Archive for Solar and Stellar Astrophysics

Weekly Update from the Open Journal of Astrophysics – 28/02/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on February 28, 2026 by telescoper

It’s Saturday once more, so it’s time for another update of activity at the Open Journal of Astrophysics. It has been a busy week. Since the last update we have published a further nine papers, bringing the number in Volume 9 (2026) to 45 and the total so far published by OJAp up to 493.

I will continue to include the posts made on our Mastodon account (on Fediscience) to encourage you to visit it. Mastodon is a really excellent service, and a more than adequate replacement for X/Twitter (which nobody should be using); these announcements also show the DOI for each paper.

The first four papers this week were all published on Monday 23rd February.

The first paper to report is “A Bayesian Exploration of The Mass of the Ursa Major III: Kinematics, Rotation and their influence on the Mass to Light Ratio” by Tim R. Adams (U. Sydney, Australia), Brendon J. Brewer (U. Auckland, New Zealand) and Geraint F. Lewis (Sydney). This paper, in the folder Astrophysics of Galaxies, describes an investigation of the kinematics of potential ultra-faint dwarf galaxy UMa III/U1, finding a preference for a non-rotating model; the object’s nature remains uncertain.

The overlay is here:

You can find the officially accepted version on arXiv here and the announcement on Fediverse here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "A Bayesian Exploration of The Mass of the Ursa Major III: Kinematics, Rotation and their influence on the Mass to Light Ratio" by Tim R. Adams (U. Sydney, Australia), Brendon J. Brewer (U. Auckland, New Zealand) and Geraint F. Lewis (Sydney)

doi.org/10.33232/001c.158197

February 23, 2026, 7:35 am 2 boosts 1 favorites

The second paper is “The Impact of Baryonic Effects on the Dynamical Masses Inferred Using Satellite Kinematics” by Josephine F.W. Baggen, Frank C. van den Bosch, and Kaustav Mitra (Yale U., USA). This paper, also in the folder Astrophysics of Galaxies, presents a model to assess the impact of stars and gas on satellite kinematics, showing that these baryonic effects can reduce the satellite velocity dispersion and increase inferred central galaxy masses.

The overlay for this one is here:

The official version of the paper can be found on arXiv here and the Fediverse announcement here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "The Impact of Baryonic Effects on the Dynamical Masses Inferred Using Satellite Kinematics" by Josephine F.W. Baggen, Frank C. van den Bosch, and Kaustav Mitra (Yale U., USA)

doi.org/10.33232/001c.158198

February 23, 2026, 7:47 am 1 boosts 1 favorites

The third paper this week, and the third published on Monday 23rd February, and the third in the folder Astrophysics of Galaxies, is “MEGATRON: Disentangling Physical Processes and Observational Bias in the Multi-Phase ISM of High-Redshift Galaxies” by Nicholas Choustikov (U. Oxford, UK) and 12 others based in UK, USA, France, Korea and Belgium. The study uses MEGATRON simulations to analyze the interstellar medium (ISM) of high-redshift galaxies, finding it denser and less metal-enriched than local galaxies with implications for line ratios as diagnostics

The overlay is here:

The official version can be found on arXiv here and the Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "MEGATRON: Disentangling Physical Processes and Observational Bias in the Multi-Phase ISM of High-Redshift Galaxies" by Nicholas Choustikov (U. Oxford, UK) and 12 others based in UK, USA, France, Korea and Belgium

doi.org/10.33232/001c.158199

February 23, 2026, 8:02 am 2 boosts 1 favorites

The fourth paper this week, also published on Monday 23rd February, but in the folder Instrumentation and Methods for Astrophysics, is “Redshift Assessment Infrastructure Layers (RAIL): Rubin-era photometric redshift stress-testing and at-scale production” by the RAIL Team (31 authors) and the Dark Energy Science Collaboration. The article introduces Redshift Assessment Infrastructure Layers (RAIL), an open-source Python library for large-scale probabilistic photo-z estimation, useful for extragalactic research and not limited to LSST data.

Here is the overlay:

The official version can be found on arXiv here and the Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Redshift Assessment Infrastructure Layers (RAIL): Rubin-era photometric redshift stress-testing and at-scale production" by the RAIL Team (31 authors) and the Dark Energy Science Collaboration

doi.org/10.33232/001c.158200

February 23, 2026, 8:32 am 1 boosts 1 favorites

Moving on to Tuesday 24th February, the fifth paper this week, is “Feedback shaped the galaxy morphological sequence in presence of mergers” by Masafumi Noguchi (Tohoku University, Japan). This article was published in the folder Astrophysics of Galaxies. This study suggests that galaxy morphology, specifically the mass ratios of bulges and disks, is influenced by galaxy mergers and feedback processes from active galactic nuclei and supernovae.

The overlay is here:

The accepted version can be found on arXiv here, and the fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Feedback shaped the galaxy morphological sequence in presence of mergers" by Masafumi Noguchi (Tohoku University, Japan)

doi.org/10.33232/001c.158272

February 24, 2026, 7:21 am 1 boosts 0 favorites

The sixth paper this week is “HelioSpectrotron 5000: an interactive solar atlas” by Alexander G.M. Pietrow (AIP Potsdam, Germany). This was published on Tuesday 24th February in the folder Solar and Stellar Astrophysics. This describes HelioSpectrotron~5000 (HS5000), which is an interactive solar spectral atlas that allows comparison between high-resolution spectra and ground-based instrument observations, aiding in wavelength calibration and line identification. The software can be found here; I had a play with it yesterday and it’s very easy to use!

The overlay is here:

You can find the officially accepted version on arXiv here and the Mastodon announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "HelioSpectrotron 5000: an interactive solar atlas" by Alexander G.M. Pietrow (AIP Potsdam, Germany)

doi.org/10.33232/001c.158273

February 24, 2026, 7:35 am 1 boosts 0 favorites

The seventh paper of this week was published on Thursday 26th February is “The Rise of Ionized Gas Filaments in Early-Type Galaxies” by Ryan Eskenasy (U. Kentucky, USA), Valeria Olivares (Universidad de Santiago de Chile) and Yuanyuan Su (U. Kentucky, USA). This article, in the folder Astrophysics of Galaxies, is an exploration of the formation of multiphase filamentary nebulae in early-type galaxies (ETGs), using VLT-MUSE IFU observations of 126 non-central ETGs, focussing on the hot gas components thereof.

The overlay is here:

The officially accepted version of this paper can be found on the arXiv here and the Mastodon announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "The Rise of Ionized Gas Filaments in Early-Type Galaxies" by Ryan Eskenasy (U. Kentucky, USA), Valeria Olivares (Universidad de Santiago de Chile) and Yuanyuan Su (U. Kentucky, USA)

doi.org/10.33232/001c.158379

February 26, 2026, 7:27 am 1 boosts 0 favorites

Number eight for this week is “Relationship Between Major Stellar Physical Parameters and Normal Mode Frequencies in Accreting White Dwarf Stars” by Praphull Kumar, Dean M. Townsley and Hunter Anz (U. Alabama, USA). This was published on Thursday 26th February in the category Solar and Stellar Astrophysics; the paper presents a new method for identifying pulsation modes in white dwarfs, improving upon previous models by using more realistic parameters and considering thermohaline mixing and element diffusion. The overlay is here:

The final version of this paper can be found on the arXiv here and the Mastodon announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Relationship Between Major Stellar Physical Parameters and Normal Mode Frequencies in Accreting White Dwarf Stars" by Praphull Kumar, Dean M. Townsley and Hunter Anz (U. Alabama, USA)

doi.org/10.33232/001c.158380

February 26, 2026, 7:37 am 1 boosts 0 favorites

The ninth, and final, paper for this week is “A Semi-Supervised Learning Method for the Identification of Bad Exposures in Large Imaging Surveys” by Yufeng Luo (U. Wyoming, USA) and 8 others from the DESI Legacy Imaging Surveys Team. This was published on Friday 27th February, i.e yesterday, in the folder Instrumentation and Methods for Astrophysics. The paper describes a machine-learning approach for detecting poor-quality exposures in large astronomical imaging surveys, proving efficient and accurate in identifying problematic exposures.

The overlay is here:

The official version on arXiv can be found here and the Mastodon announcement follows:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "A Semi-Supervised Learning Method for the Identification of Bad Exposures in Large Imaging Surveys" by Yufeng Luo (U. Wyoming, USA) and 8 others from the DESI Legacy Imaging Surveys Team

doi.org/10.33232/001c.158430

February 27, 2026, 8:52 am 1 boosts 1 favorites

And that concludes this week’s update. We have now published 45 papers in two complete months of 2026, on which basis we can estimate about 270 papers in the year.

P.S. Thank you to the many people who responded to the latest call for editors. I’ve been sending out invitations and getting people onboard as quickly as I can, but I still have a number to get to so please bear with me!

Weekly Update from the Open Journal of Astrophysics – 21/02/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on February 21, 2026 by telescoper

It’s Saturday once more so time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further six papers, bringing the number in Volume 9 (2026) to 36 and the total so far published by OJAp up to 484.

I will continue to include the posts made on our Mastodon account (on Fediscience) to encourage you to visit it. Mastodon is a really excellent service, and a more than adequate replacement for X/Twitter (which nobody should be using); these announcements also show the DOI for each paper.

The first paper to report this week is “SKA-Low simulations for a cosmic dawn/epoch of reionisation deep field” by Anna Bonaldi, Philippa Hartley, Simon Purser & Omkar Bait (SKAO, UK), Eunseong Lee (U. Manchester, UK), Robert Braun (SKAO), Florent Mertens (Sorbonne Université, France), Andrea Bracco (Osservatorio Astrofisico di Arcetri, IT), Wendy Williams (SKAO) and Cath Trott (Curtin U., Australia). This paper presents a simulation of an SKA-Low cosmic dawn/epoch of reionisation observation to advance foreground-mitigation approaches: the simulation includes various sky components and modelled errors, allowing for efficacy assessment. It was published on Monday 16th February in the folder Cosmology and Nongalactic Astrophysics.

The overlay is here:

You can find the officially accepted version on arXiv here and the announcement on Fediverse here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "SKA-Low simulations for a cosmic dawn/epoch of reionisation deep field" by Anna Bonaldi, Philippa Hartley, Simon Purser & Omkar Bait (SKAO, UK), Eunseong Lee (U. Manchester, UK), Robert Braun (SKAO), Florent Mertens (Sorbonne Université, France), Andrea Bracco (Osservatorio Astrofisico di Arcetri, IT), Wendy Williams (SKAO) and Cath Trott (Curtin U., Australia)

doi.org/10.33232/001c.157763

February 16, 2026, 8:28 am 1 boosts 1 favorites

The second paper is “V717 Andromedae: An Active Low Mass Ratio Contact Binary” by Surjit S. Wadhwa (Western Sydney U. Australia), Marko Grozdanovic (Astronomical Observatory Belgrade, Serbia), and Nicholas F.H Tothill, Miroslav D. Filipovic, Ain Y. De Horta (Western Sydney U.). This was also published on Monday 1th February, but in the folder Solar and Stellar Astrophysics. The article discusses the contact binary V717 Andromedae, an extreme low mass ratio system with high inclination and moderate contact, showing signs of chromospheric activity but stable and not a merger candidate

The overlay for this one is here:

The official version of the paper can be found on arXiv here and the Fediverse announcement here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "V717 Andromedae: An Active Low Mass Ratio Contact Binary" by Surjit S. Wadhwa (Western Sydney U. Australia), Marko Grozdanovic (Astronomical Observatory Belgrade, Serbia), and Nicholas F.H Tothill, Miroslav D. Filipovic, Ain Y. De Horta (Western Sydney U.)

doi.org/10.33232/001c.157764

February 16, 2026, 8:56 am 0 boosts 0 favorites

Next, published on Tuesday 17th February in the folder High-Energy Astrophysical Phenomena, is “DIPLODOCUS II: Implementation of transport equations and test cases relevant to micro-scale physics of jetted astrophysical sources” by Christopher N Everett (Oxford U., UK), Marc Klinger-Plaisier (U. Amsterdam, NL) and Garret Cotter (Oxford). This one discusses further applications of DIPLODOCUS, which is a framework developed for particle distribution transport, with its numerical implementation detailed in Diplodocus.jl. It uses a new sampling technique and is tested on micro-scale physical effects. The first paper in the series can be found here.

The overlay is here:

The official version can be found on arXiv here and the Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "DIPLODOCUS II: Implementation of transport equations and test cases relevant to micro-scale physics of jetted astrophysical sources" by Christopher N Everett (Oxford U., UK), Marc Klinger-Plaisier (U. Amsterdam, NL) and Garret Cotter (Oxford)

doi.org/10.33232/001c.157823

February 17, 2026, 7:13 am 1 boosts 2 favorites

The fourth paper this week, also published on Tuesday 17th February, but in the folder Cosmology and Nongalactic Astrophysics is “Revisiting the Great Attractor: The Local Group’s streamline trajectory, cosmic velocity and dynamical fate” by Richard Stiskalek (Oxford U., UK), Harry Desmond (U. Portsmouth, UK), Stuart McAlpine (Stockholm, SE), Guilhem Lavaux (Sorbonne Université, FR), Jens Jasche (Stockholm) and Michael J. Hudson (U. Waterloo, Canada). This paper revisits the so-called “Great Attractor” concept, finding that it doesn’t dominate the Local Group’s cosmic velocity; multiple structures contribute to the motion, with no single attractor accounting for the flow.

Here is the overlay:

The official version can be found on arXiv here and the Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Revisiting the Great Attractor: The Local Group’s streamline trajectory, cosmic velocity and dynamical fate" by Richard Stiskalek (Oxford U., UK), Harry Desmond (U. Portsmouth, UK), Stuart McAlpine (Stockholm, SE), Guilhem Lavaux (Sorbonne Université, FR), Jens Jasche (Stockholm) and Michael J. Hudson (U. Waterloo, Canada)

doi.org/10.33232/001c.157824

February 17, 2026, 7:33 am 3 boosts 1 favorites

The fifth paper this week, is “JWST observations of three long-period AM CVn binaries: detection of the donors and hints of magnetically truncated disks” by Kareem El-Badry (Caltech), Antonio C. Rodriguez (CfA Harvard), Matthew J. Green (U. Oklahoma) & Kevin B. Burdge (MIT); all based in the USA. The article was published on Thursday 19th February 2026 in the folder Solar and Stellar Astrophysics. The paper describes high-cadence infrared spectroscopy used to analyze three long-period, eclipsing AM CVn (AM Canum Venaticorum) binaries; findings suggest the presence of magnetized white dwarf accretors, with surface magnetic fields of 30-100 kG.

The overlay is here:

The accepted version can be found on arXiv here, and the fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "JWST observations of three long-period AM CVn binaries: detection of the donors and hints of magnetically truncated disks" by Kareem El-Badry (Caltech), Antonio C. Rodriguez (CfA Harvard), Matthew J. Green (U. Oklahoma) & Kevin B. Burdge (MIT); all in USA

doi.org/10.33232/001c.157856

February 18, 2026, 8:15 am 1 boosts 0 favorites

Finally for this week we have “Ultra-long Gamma-ray Bursts from Micro-Tidal Disruption Events: The Case of GRB 250702B” by Paz Beniamini (Open University, IL), Hagai B. Perets (Technion, IL) and Jonathan Granot (Open University, IL); all based in Israel. The paper was published on Friday 18th February 2026 in the folder High-Energy Astrophysical Phenomena.

The overlay is here:

You can find the officially accepted version on arXiv here and the Mastodon announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Ultra-long Gamma-ray Bursts from Micro-Tidal Disruption Events: The Case of GRB 250702B" by Paz Beniamini (Open University, IL), Hagai B. Perets (Technion, IL) and Jonathan Granot (Open University, IL)

doi.org/10.33232/001c.157985

February 20, 2026, 8:43 am 0 boosts 0 favorites

And that concludes this week’s update. I will do another next Saturday, by which time I expect we will have published a similar number of papers to this week.

Weekly Update from the Open Journal of Astrophysics – 07/02/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on February 7, 2026 by telescoper

It’s Saturday once more so time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further six papers, bringing the number in Volume 9 (2026) to 24 and the total so far published by OJAp up to 472.

I will continue to include the posts made on our Mastodon account (on Fediscience) to encourage you to visit it. Mastodon is a really excellent service, and a more than adequate replacement for X/Twitter which nobody should be using; these announcement also show the DOI for each paper.

The first paper to report this week is “The Impact of Star Formation and Feedback Recipes on the Stellar Mass and Interstellar Medium of High-Redshift Galaxies” by Harley Katz (U. Chicago, USA), Martin P. Rey (U. Oxford, UK), Corentin Cadiou (Lund U., Sweden) Taysun Kimm (Yonsei U., Korea) and Oscar Agertz (Lund). This paper was published on Monday 2nd February 2026 in the folder Astrophysics of Galaxies. It introduces MEGATRON, a new model for galaxy formation simulations, highlighting that feedback energy controls star formation at high redshift and highlighting the importance of the interstellar medium.

The overlay is here:

You can find the officially accepted version on arXiv here and the announcement on Fediverse here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "The Impact of Star Formation and Feedback Recipes on the Stellar Mass and Interstellar Medium of High-Redshift Galaxies" by Harley Katz (U. Chicago, USA), Martin P. Rey (U. Oxford, UK), Corentin Cadiou (Lund U., Sweden) Taysun Kimm (Yonsei U., Korea) and Oscar Agertz (Lund)

doi.org/10.33232/001c.156097

February 2, 2026, 11:02 am 1 boosts 1 favorites

The second paper is “Photometric Redshifts in JWST Deep Fields: A Pixel-Based Alternative with DeepDISC” by Grant Merz (U. Illinois at Urbana-Champaign) and 6 others, all based in the USA. This paper was published on Monday February 2nd 2026 in the folder Instrumentation and Methods for Astrophysics. This paper explores the effectiveness of the DeepDISC machine learning algorithm in estimating photometric redshifts from near-infrared data, demonstrating its potential for larger image volumes and spectroscopic samples

The overlay for this one is here:

The official version of the paper can be found on arXiv here and the Fediverse announcement here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Photometric Redshifts in JWST Deep Fields: A Pixel-Based Alternative with DeepDISC" by Grant Merz (U. Illinois at Urbana-Champaign) and 6 others, all based in the USA

doi.org/10.33232/001c.156099

February 2, 2026, 11:23 am 1 boosts 0 favorites

Next, published on Wednesday 4th February in the folder Astrophysics of Galaxies, is “Inferring Interstellar Medium Density, Temperature, and Metallicity from Turbulent H II Regions” by Larrance Xing (U. Chicago, USA), Nicholas Choustikov (U. Oxford, UK), Harley Katz (U. Chicago) and Alex J. Cameron (DAWN, Denmark). This paper argues that supersonic turbulenc affects the interpretation of H II region properties, potentially impacting inferred metallicity, ionization, and excitation from in nebular emission lines, motivating more extensive modelling.

The overlay is here:

The official version can be found on arXiv here and the Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Inferring Interstellar Medium Density, Temperature, and Metallicity from Turbulent H II Regions" by Larrance Xing (U. Chicago, USA), Nicholas Choustikov (U. Oxford, UK), Harley Katz (U. Chicago) and Alex J. Cameron (DAWN, Denmark)

doi.org/10.33232/001c.156223

February 4, 2026, 8:20 am 1 boosts 0 favorites

The fourth paper this week, also published on Wednesday 4th February, but in the folder Solar and Stellar Astrophysics, is “A Systematic Search for Big Dippers in ASAS-SN” by B. JoHantgen, D. M. Rowan, R. Forés-Toribio, C. S. Kochanek, & K. Z. Stanek (Ohio State University, USA), B. J. Shappee (U. Hawaii, USA), Subo Dong (Peking University), J. L. Prieto Universidad Diego Portales, Chile) and Todd A. Thompson (Ohio State). This study identifies 4 new dipper stars and 15 long-period eclipsing binary candidates using ASAS-SN light curves and multi-wavelength data, categorizing them based on their characteristics.

Here is the overlay:

The official version can be found on arXiv here and the Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "A Systematic Search for Big Dippers in ASAS-SN" by B. JoHantgen , D. M. Rowan, R. Forés-Toribio, C. S. Kochanek, & K. Z. Stanek (Ohio State University, USA), B. J. Shappee (U. Hawaii, USA), Subo Dong (Peking University), J. L. Prieto Universidad Diego Portales, Chile) and Todd A. Thompson (Ohio State)

doi.org/10.33232/001c.156224

February 4, 2026, 8:40 am 1 boosts 0 favorites

Fifth, and next to last this week we have “Unveiling the drivers of the Baryon Cycles with Interpretable Multi-step Machine Learning and Simulations” by Mst Shamima Khanom, Benjamin W. Keller and Javier Ignacio Saavedra Moreno (U. Memphis, USA). This paper was published on Thursday 5th February 2026 in the folder Astrophysics of Galaxies. This study uses machine learning methods to understand how galaxies lose or retain baryons, highlighting the relationship between baryon fraction and various galactic measurements.

The overlay is here:

The accepted version can be found on arXiv here, and the fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Unveiling the drivers of the Baryon Cycles with Interpretable Multi-step Machine Learning and Simulations" by Mst Shamima Khanom, Benjamin W. Keller and Javier Ignacio Saavedra Moreno (U. Memphis, USA)

doi.org/10.33232/001c.156271

February 5, 2026, 7:39 am 1 boosts 1 favorites

Finally for this week we have “The Bispectrum of Intrinsic Alignments: II. Precision Comparison Against Dark Matter Simulations” by Thomas Bakx (Utrecht U., Netherlands), Toshiki Kurita (MPA Garching, Germany), Alexander Eggemeier (U. Bonn, Germany), Nora Elisa Chisari (Utrecht) and Zvonimir Vlah (Ruđer Bošković Institute, Croatia). This paper was accepted in December, but publication got delayed by the Christmas effect so was published on February 6th 2026, in the folder Cosmology and Nongalactic Astrophysics. This study uses N-body simulations to accurately measure three-dimensional bispectra of halo intrinsic alignments and dark matter overdensities, providing a method to determine higher order shape bias parameters.

The overlay is here:

You can find the published version of the article here, and the Mastodon announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "The Bispectrum of Intrinsic Alignments: II. Precision Comparison Against Dark Matter Simulations" by Thomas Bakx (Utrecht U., Netherlands), Toshiki Kurita (MPA Garching, Germany), Alexander Eggemeier (U. Bonn, Germany), Nora Elisa Chisari (Utrecht) and Zvonimir Vlah (Ruđer Bošković Institute, Croatia)

doi.org/10.33232/001c.156361

February 6, 2026, 7:43 am 1 boosts 0 favorites

And that concludes this week’s update. I will do another next Saturday.

Weekly Update from the Open Journal of Astrophysics – 24/01/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , on January 24, 2026 by telescoper

It’s Saturday once more so time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further three papers, bringing the number in Volume 9 (2026) to 14 and the total so far published by OJAp up to 462. This week was slightly affected by a Federal holiday in the USA on January 19th; there were no arXiv announcements the following day.

I will continue to include the posts made on our Mastodon account (on Fediscience) to encourage you to visit it. Mastodon is a really excellent service, and a more than adequate replacement for X/Twitter which nobody should be using.

The first paper to report this week is “The Properties of Little Red Dot Galaxies in the ASTRID Simulation” by Patrick LaChance, Rupert A. C. Croft, Tiziana Di Matteo & Yihao Zhou (Carnegie Mellon U.), Fabio Pacucci (Harvard-Smithsonian CfA), Yueying Ni (U. Michigan Ann Arbor), Nianyi Chen (Princeton U.) and Simeon Bird (UC Riverside), all based in the USA. This paper was published on Monday 19th January 2026 in the folder Cosmology and Nongalactic Astrophysics; the study analyses mock observations of “Little Red Dot” galaxies created from the ASTRID simulation, having high stellar masses and containing massive black holes; not all features match real observations.

The overlay is here:

You can find the officially accepted version on arXiv here and the announcement on Fediverse here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics; "The Properties of Little Red Dot Galaxies in the ASTRID Simulation" by Patrick LaChance, Rupert A. C. Croft, Tiziana Di Matteo & Yihao Zhou (Carnegie Mellon U.), Fabio Pacucci (Harvard-Smithsonian CfA), Yueying Ni (U. Michigan Ann Arbor), Nianyi Chen (Princeton U.) and Simeon Bird (UC Riverside), all based in the USA

doi.org/10.33232/001c.155493

January 19, 2026, 10:33 am 2 boosts 1 favorites

The second paper is “Angular bispectrum of matter number counts in cosmic structures” by Thomas Montandon (U. Montpellier, France), Enea Di Dio (U. Genève, Switzerland), Cornelius Rampf (Ruđer Bošković Institute, Croatia) and Julian Adamek (U. Zürich, Switzerland). This was published on Wednesday January 21st, also in the folder Cosmology and Nongalactic Astrophysics. This paper presents thee first full-sky computation of the angular bispectrum in second-order perturbation theory, offering insights into the Universe’s initial conditions, gravity, and cosmological parameters. The results align well with simulations.

The overlay for this one is here:

The official version of the paper can be found on arXiv here and the Fediverse announcement here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Angular bispectrum of matter number counts in cosmic structures" by Thomas Montandon (U. Montpellier, France), Enea Di Dio (U. Genève, Switzerland), Cornelius Rampf (Ruđer Bošković Institute, Croatia) and Julian Adamek (U. Zürich, Switzerland)

doi.org/10.33232/001c.155624

January 21, 2026, 9:30 am 1 boosts 0 favorites

Next, and last for this week, we have “The Kinematic Properties of TŻO Candidate HV 11417 with Gaia DR3” by Anna J. G. O’Grady (Carnegie Mellon University, USA). This was published on Wednesday 21st January 2026 in the folder Solar and Stellar Astrophysics. This work uses updated data to confirm that HV 11417, a potential Thorne-Żytkow Object, is probably part of the Small Magellanic Cloud and qualifies as a runaway star.

The overlay is here:

The official version can be found on arXiv here and the Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "The Kinematic Properties of TŻO Candidate HV 11417 with Gaia DR3" by Anna J. G. O'Grady (Carnegie Mellon University, USA)

doi.org/10.33232/001c.155625

January 21, 2026, 9:45 am 1 boosts 1 favorites

That concludes the update for this week. I will do another next Saturday.

Weekly Update from the Open Journal of Astrophysics – 13/12/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , , , , , , on December 13, 2025 by telescoper

It’s time once again for the usual Saturday morning update of the week’s new papers at the Open Journal of Astrophysics. Since the last update we have published a further five papers, which brings the number in Volume 8 (2025) up to 195, and the total so far published by OJAp up to 430.

The first paper this week is “Cosmic Rays Masquerading as Cool Cores: An Inverse-Compton Origin for Cool Core Cluster Emission” by Philip F. Hopkins (Caltech), Eliot Quataert (Princeton), Emily M. Silich, Jack Sayers, Sam B. Ponnada and Isabel S. Sands (Caltech).  This was published on Tuesday 9th December 2025 in the folder marked High-Energy Astrophysical Phenomena. It presents an argument  that cosmic-ray inverse-compton emission could contribute significantly to the X-ray surface brightness (SB) in cool-corre clusters, implying that gas densities may have been overestimated therein.

The overlay is here:

You can find the officially accepted version on arXiv here and the Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Cosmic Rays Masquerading as Cool Cores: An Inverse-Compton Origin for Cool Core Cluster Emission" by

Philip F. Hopkins (Caltech), Eliot Quataert (Princeton), Emily M. Silich, Jack Sayers, Sam B. Ponnada and Isabel S. Sands (Caltech)

doi.org/10.33232/001c.154053

December 9, 2025, 7:22 am 1 boosts 0 favorites

The second paper of the week is “Detecting False Positives With Derived Planetary Parameters: Experimenting with the KEPLER Dataset” by Ayan Bin Rafaih (Aitchison College, Lahore, Pakistan) and Zachary Murray (Université Côte d’Azur, France). This one was published on 9th December 2025 in the folder Earth and Planetary Astrophysics. It is an investigation into the performance of a range of machine-learning algorithms on the KEPLER dataset, using precision-recall trade-off and accuracy metrics.

The overlay is here:

You can find the official version of this one on arXiv here. The federated announcement on Mastodon is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Detecting False Positives With Derived Planetary Parameters: Experimenting with the KEPLER Dataset" by Ayan Bin Rafaih (Aitchison College, Lahore, Pakistan) and Zachary Murray (Université Côte d’Azur, France)

doi.org/10.33232/001c.154054

December 9, 2025, 7:34 am 1 boosts 0 favorites

Next one up is “The role of peculiar velocity uncertainties in standard siren cosmology” by Chris Blake and Ryan J. Turner (Swinburne, Australia). This paper discusses the impact of peculiar velocities on the error in H0 determinations from local distance indicators with observed redshifts, incorporating the effect of bulk flows. It was published on Tuesday 9th December in the folder Cosmology and Nongalactic Astrophysics.

The overlay is here:

You can find the official accepted version on arXiv here. The fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "The role of peculiar velocity uncertainties in standard siren cosmology" by Chris Blake and Ryan J. Turner (Swinburne, Australia)

doi.org/10.33232/001c.154055

December 9, 2025, 7:47 am 1 boosts 0 favorites

The fourth article of the week is “Transient QPOs of Fermi-LAT blazars with Linearly Multiplicative Oscillations” by P. Penil (Clemson University, USA) and 7 others based in the USA, Italy and Germany. This was published on Thursday 10th December in the folder High-Energy Astrophysical Phenomena. This paper presents an investigation of patterns of quasi-periodic oscillations in observed blazar systems characterized by periodic multiplicative amplitudes including both the periodicities and long-term variations.  The overlay is here:

You can find the official published version on arXiv here. The Fediverse announcement follows:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Transient QPOs of Fermi-LAT blazars with Linearly Multiplicative Oscillations" by P. Penil (Clemson University, USA) and 7 others based in the USA, Italy and Germany

doi.org/10.33232/001c.154123

December 10, 2025, 12:22 pm 0 boosts 1 favorites

The last paper for this week is “Tidally Delayed Spin-Down of Very Low Mass Stars” by Ketevan Kotorashvili and Eric G. Blackman (U. Rochester, USA). This was published on Friday 12th December (yesterday) in the folder Solar and Stellar Astrophysics. It discusses the effect of tides from sub-stellar companions on rotational evolution of very low-mass stars, suggesting that these may explain the dearth of field, late-type M dwarfs with intermediate rotation periods.

The overlay is here:

 

You can find the officially-accepted version on arXiv here, and the Mastodon announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Tidally Delayed Spin-Down of Very Low Mass Stars" by Ketevan Kotorashvili and Eric G. Blackman (U. Rochester, USA)

doi.org/10.33232/001c.154268

December 12, 2025, 10:31 am 1 boosts 0 favorites

 

And that concludes the update for this week. I will do another of these regular announcements next Saturday, which will be the last such update for 2025. Will we make it past 200 for the year? Tune in next week to find out!

Weekly Update from the Open Journal of Astrophysics – 01/11/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , on November 1, 2025 by telescoper

It’s time once again for the usual Saturday update of the week’s new papers at the Open Journal of Astrophysics (although a bit later in the day than usual). Since the last update we have published another two papers, which brings the number in Volume 8 (2025) up to 163, and the total so far published by OJAp up to 398.

The first paper this week is “Instability and vertical eccentricity variation in global hydrodynamic disk simulations” by Janosz W Dewberry (U. Mass. Amherst, USA), Henrik N. Latter and Gordon I. Ogilvie (U. Cambridge, UK) and Sebastien Fromang (U. Paris Saclay, France). This article was published in the folder Solar and Stellar Astrophysics on Tuesday 28th October 2025; it discusses the instabilities and eccentricity variations generated in numerical hydrodynamic simulations of accretion disks.

The overlay is here:

You can find the officially accepted version on arXiv here.

The Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Instability and vertical eccentricity variation in global hydrodynamic disk simulations" by Janosz W Dewberry (U. Mass. Amherst, USA), Henrik N Latter and Gordon I Ogilvie (U. Cambridge, UK) & Sebastien Fromang (U. Paris Saclay, France)

doi.org/10.33232/001c.146332

October 28, 2025, 9:43 am 2 boosts 0 favorites

The second (and last) paper of the week is “Fast X-ray Transient Detection with AXIS: application to Magnetar Giant Flares” by Michela Negro (Louisiana State University, USA) and 8 others based in the USA and Canada. This one was also published on Tuesday 28th October, but in the folder High-Energy Astrophysical Phenomena. It presents a feasibility study of detecting Magnetar Giant Flares with the Advanced X-ray Imaging Satellite (AXIS). The overlay is here:

You can find the official version of this one on arXiv here. The announcement on Mastodon is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Fast X-ray Transient Detection with AXIS: application to Magnetar Giant Flares" by Michela Negro (Louisiana State University, USA) and 8 others based in the USA and Canada

doi.org/10.33232/001c.146360

October 28, 2025, 10:02 am 1 boosts 1 favorites

It being a relatively slow week we didn’t reach the 400 mark as I thought we might, but we will probably get there next week. After 10 months of the year 2025, in which we have published 163 papers, a rough projection for the 2025 total is 195. We do have some extra papers up our sleeve, however, so we might well reach 200 for the year. We will find out soon enough!

Weekly Update from the Open Journal of Astrophysics – 20/09/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , on September 20, 2025 by telescoper

It’s Saturday again, so it’s time for a summary of the week’s new papers at the Open Journal of Astrophysics. Since the last update we have published two new papers, which brings the number in Volume 8 (2025) up to 136, and the total so far published by OJAp up to 371.

The first paper to report this week is “The Moon as a possible source for Earth’s co-orbital bodies” by Rafael Sfair, L. C. Gomes, O. C. Winter & R. A. Moraes (São Paulo State University, Brazil), G. Borderes-Motta (Astronomical Institute of the Czech Academy of Sciences, Czech Republic) and C. M. Schäfer (Universität Tübingen, Germany). This paper was published on Monday 15th September, in the folder Earth and Planetary Astrophysics, and it presents a numerical exploration of the ejection velocities and launch locations necessary for lunar ejecta to evolve into Earth’s co-orbital bodies.

The overlay is here:

 

You can make this larger by clicking on it.  The officially accepted version of this paper can be found on the arXiv here.

The second paper this week, published on Friday 19th September in the folder Solar and Stellar Astrophysics, is  “Jet-Driven Formation of Bipolar Rings in Planetary Nebulae: Numerical Simulations Inspired by NGC 1514” by Muhammad Akashi, Ealeal Bear, and Noam Soker (Technion, Haifa, Israel). This paper presents evidence from numerical simulations notion that jets play a substantial role in shaping planetary nebulae (PNe).

The corresponding overlay is here:

 

You can find the officially accepted version on arXiv here.

Weekly Update from the Open Journal of Astrophysics – 13/09/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , on September 13, 2025 by telescoper

It’s Saturday again, so it’s time for another summary of the week’s new papers at the Open Journal of Astrophysics. Since the last update we have published seven new papers, which brings the number in Volume 8 (2025) up to 134, and the total so far published by OJAp up to 369. We seem to be emerging for the slight late-summer hiatus we have experienced over the last few weeks.

Anyway, the first paper to report this week is “Observing the Sun with the Atacama Large Aperture Submillimeter Telescope (AtLAST): Forecasting Full-disk Observations” by Mats Kirkaune & Sven Wedemeyer (U. Oslo, Norway), Joshiwa van Marrewijk (Leiden U., Netherlands), Tony Mroczkowski (ESO, Garching, Germany) and Thomas W. Morris (Yale, USA). This paper discusses possible strategies and parameters for full-disk observations of the Sun using the proposed Atacama Large Aperture Submillimeter Telescope (AtLAST). It was published on Tuesday 9th September 2025 in the folder Solar and Stellar Astrophysics.

The overlay is here:

 

You can make this larger by clicking on it.  The officially accepted version of this paper can be found on the arXiv here.

The second paper this week, published on Wednesday 10th September in the folder Cosmology and NonGalactic Astrophysics, is “The exact non-Gaussian weak lensing likelihood: A framework to calculate analytic likelihoods for correlation functions on masked Gaussian random fields” by Veronika Oehl and Tilman Tröster (ETH Zurich, Switzerland).  This paper shows how to calculate likelihoods for the correlation functions of spin-2 Gaussian random fields defined on the sphere in the presence of a mask with applications to weak gravitational lensing.

The overlay is here:

and you can find the final accepted version on arXiv here.

Next one up, the third paper this week, is  “Subspace Approximation to the Focused Transport Equation. II. The Modified Form” by B. Klippenstein and Andreas Shalchi (U. Manitoba, Canada). This was also published on 10th September 2025 in the folder Solar and Stellar Astrophysics. It is about solving the focused transport equation analytically and numerically using the subspace method in two or more dimensions.

You can find the final accepted version on arXiv here.

The fourth paper of this week was also published on Wednesday 10th September. It is “Mass models of galaxy clusters from a non-parametric weak-lensing reconstruction” by Tobias Mistele (Case Western Reserve U., USA), Federico Lelli (INAF, Firenze, Italy), Stacy McGaugh (Case Western), James Schombert (U. Oregon, USA) and Benoit Famaey (Université de Strasbourg, France).  Published in the folder Cosmology and NonGalactic Astrophysics, it presents new, non-parametric deprojection method for weak gravitational lensing applied to a sample of galaxy clusters. The overlay is here:

You can find the officially accepted version on arXiv here.

The fifth paper of the week is “A Swift Fix II: Physical Parameters of Type I Superluminous Supernovae” by Jason T. Hinkle & Benjamin J. Shappee (U. Hawaii, USA) and Michael A. Tucke (Ohio State, USA). This one was published on Thursday 11th September 2025 in the folder High-Energy Astrophysical Phenomena. The paper uses recalibrated Swift photometry to recompute peak luminosities and other properties of a sample of superluminous Type I supernovae. The overlay is here:

You can find the official accepted version on arXiv here.

Paper No. 6 for this week is “Detailed Microwave Continuum Spectra from Bright Protoplanetary Disks in Taurus” by Caleb Painter (Harvard, USA) and 11 others, too numerous to mention by name, based in the USA, Germany, Mexico and Taiwan.  This one was published in the folder marked Solar and Stellar Astrophysics on September 11th 2025. It presents new observations sampling the microwave (4-360 GHz) continuum spectra from eight young stellar systems in the Taurus region. The overlay is here:

 

The final version can be found on arXiv here.

The last paper for this update is “On Soft Clustering For Correlation Estimators” by Edward Berman (Northeastern University, USA) and 13 others based in the USA, France, Denmark and Finland and Cosmos-Web:The JWST Cosmic Origins Survey. This was published on Friday 12th September 2025 in the folder Instrumentation and Methods for Astrophysics. It presents an algorithm for estimating correlations that clusters objects in a probabilistic fashion, enabling the uncertainty caused by clustering to be quantified simply through model inference. The overlay is here:

You can find the final version on arXiv here.

And that’s all the papers for this week. I’ve noticed a significant recent increase in the number of papers in Solar and Stellar Astrophysics, which means we’re broadening our impact across the community. Which is nice.

P.S. I found out last week that, according to NASA/ADS, papers in OJAp have now accumulated over 5000 citations.

Weekly Update from the Open Journal of Astrophysics – 06/09/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , on September 6, 2025 by telescoper

It’s Saturday again, so it’s time for a summary of the week’s new papers at the Open Journal of Astrophysics. Since the last update we have published two new papers, which brings the number in Volume 8 (2025) up to 127, and the total so far published by OJAp up to 362. It’s been another relatively slow week, not least because of the Labor (sic) Day holiday in the USA on Monday which, among other things, meant there was no arXiv update on Tuesday.

Anyway, the first paper to report this week is “An analytical model for the dispersion measure of Fast Radio Burst host galaxies” by Robert Reischke, Michael Kovač & Andrina Nicola (U. Bonn, Germany), Steffen Hagstotz (Ludwig-Maximilians Universität München) and Aurel Schneider (U. Zurich, Switzlerland). This is a theoretical study of the dispersion measures (DMs) intrinsic to host galaxies of Fast Radio Burst (FRB) sources to enable separation of that from the line-of-sight DM. This one was published on Monday 1st September 2025 in the folder Cosmology and NonGalactic Astrophysics.

The overlay is here:

 

You can make this larger by clicking on it.  The officially accepted version of this paper can be found on the arXiv here.

The second paper this week, published on Wednesday 3rd Sepember in the folder Solar and Stellar Astrophysics, is “Complex spectral variability and hints of a luminous companion in the Be star + black hole binary candidate ALS 8814” by Kareem El-Badry (Caltech, USA), Matthias Fabry (Villanova U., USA), Hugues Sana (KU Leuven, Belgium), Tomer Shenar (Tel Aviv U., Israel) and Rhys Seeburger (MPA Heidelberg, Germany).

The overlay for this one is here:

 

You can find the officially accepted version on arXiv here.

And that’s all the papers for this week. It’s still a bit slow as we emerge from the summer vacations, we have a lot of papers in the pipeline that I expect to emerge pretty soon.

Weekly Update from the Open Journal of Astrophysics – 23/08/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , , , , , on August 23, 2025 by telescoper

So it’s Saturday again, so it’s time for the usual update of papers published at the Open Journal of Astrophysics which I do every Saturday. Since the last update we have published six new papers, which brings the number in Volume 8 (2025) up to 122, and the total so far published by OJAp up to 357. As I mentioned here we have overtaken the total of 120 published in Volume 7 (2024) and are on track for in excess of 180 publications in 2025.

The first paper to report this week is “Mass-feeding of jet-launching white dwarfs in grazing and common envelope evolution” by Noam Soker (Technion, Haifa, Israel). This was published on Tuesday 19th August in the folder Solar and Stellar Astrophysics. It proposes a theoretical suggestion about the production of jets in common-envelope evolution with massive stars.

The overlay is here:

You can make this larger by clicking on it, as you can with all the overlays below. The officially accepted version of this paper can be found on the arXiv here.

The second paper this week, published on Wednesday 20th August in the folder Earth and Planetary Astrophysics, is “Transition metal abundance as a key parameter for the search of Life in the Universe” by Giovanni Covone and Donato Giovannelli (University of Naples, Italy). This paper presents an argument that the availability of transition elements is an essential feature of habitability, and should be considered as such in selecting exoplanetary targets in the search for life.

The overlay is here:

You can find the officially accepted version of the paper on arXiv here.

The third paper this week, also published on 20th August 2025 in the folder Earth and Planetary Astrophysics, is “Discrete element simulations of self-gravitating rubble pile collisions: the effects of non-uniform particle size and rotation” by Job Guidos, Lucas Kolanz and Davide Lazzati (Oregon State University, USA).  This presents a new computer code for simulating the growth of granular masses through collisions of smaller particles and discusses results generated by it.

The overlay for this one is here:

You can find the officially accepted version on arXiv here.

The next paper, the fourth this week, is “Seeing the Outer Edge of the Infant Type Ia Supernova 2024epr in the Optical and Near Infrared” by W.B. Hoogendam (University of Hawaii, USA) and 32 others – too numerous to list by name – based in various institutes in the USA, Australia, UK, Denmark, Taiwan and China. This paper was also published on Wednesday 20th August 2025, but in the folder High-Energy Astrophysical Phenomena.  The article reports on the results of optical-to-near-infrared photometry and spectroscopy of the Type Ia supernova (SN Ia) 2024epr and a discusses how these challenge models for this sort of supernova.

The overlay is here:

You can find the officially accepted version on arXiv here.

The fifth paper this week is “Computing Nonlinear Power Spectra Across Dynamical Dark Energy Model Space with Neural ODEs” by Peter L. Taylor of Ohio State University (USA).  This one shows how to compute the evolution of cosmological power spectra into the non-linear regime via neural differential equations. It was published on Friday 22nd August 2025 in the folder Cosmology and NonGalactic Astrophysics. The overlay is here:

You can find the officially accepted version on arXiv here.

And finally for this week we have “Symbiotic star candidates in Gaia Data Release 3” by Samantha E. Ball & Benjamin C Bromley (University of Utah, USA) and Scott J. Kenyon (Smithsonian Observatory, USA). This paper was published on Friday 22nd August in the folder Solar and Stellar Astrophysics. It describes a new search for symbiotic star candidates in Gaia Data Release 3 (GDR3), based on astrometric, photometric, and spectroscopic information. The overlay is here:

You can find the officially accepted version of this one on arXiv here.

And that’s all the papers for this week. I suppose there will come a time when we publish a paper on every day of the week and each week’s summary will contain a paper in each of the astro-ph categories on arXiv, but we haven’t done that yet. This week we published on every day but Monday 18th August, and have papers in four of the six categories.