Archive for light curves

Weekly Update from the Open Journal of Astrophysics – 18/04/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on April 18, 2026 by telescoper

It is Saturday morning, and therefore time for yet 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 82 and the total so far published by OJAp up to 530.

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 “Beyond Spherical geometry: Unraveling complex features of objects orbiting around stars from its transit light curve using deep learning” by Ushasi Bhowmick & Shivam Kumaran (Indian Space Research Institute, Ahmedabad, India). This study uses deep neural networks to predict the shape of objects orbiting stars based on their transit light curves, demonstrating the potential to extract geometric information from these systems. It was published on Monday 13th April in the folder Earth and Planetary Astrophysics and the overlay can be seen 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: "Beyond Spherical geometry: Unraveling complex features of objects orbiting around stars from its transit light curve using deep learning" by Ushasi Bhowmick & Shivam Kumaran (ISRO, Ahmedabad, India)

doi.org/10.33232/001c.160561

April 13, 2026, 6:31 am 1 boosts 1 favorites

The second paper for this week, also published on Monday 13th April but in the folder Astrophysics of Galaxies, is “statmorph-lsst: Quantifying and correcting morphological biases in galaxy surveys” by Elizaveta Sazonova (U. Waterloo, Canada) and an international cast of 18 others. This paper presents an investigation of potential biases in quantitative morphology metrics used in galaxy evolution studies, proposing two new measurements to resolve biases, and provides a related Python package (statmorph-lsst), which can be found here on github.

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: "statmorph-lsst: Quantifying and correcting morphological biases in galaxy surveys" by Elizaveta Sazonova (U. Waterloo, Canada) and an international cast of 18 others.

doi.org/10.33232/001c.160562

April 13, 2026, 6:51 am 3 boosts 1 favorites

Next one up, the third paper of the week, one of four published on Friday 17th April, is “Disentangling the galactic and intergalactic components in 313 observed Lyman-alpha line profiles between redshift 0 and 5” by Siddhartha Gurung-López (Universitat de València, Spain) and 7 others based in Spain and Germany. Published in the folder Astrophysics of Galaxies, this paper uses the zELDA package to analyze Lyman-alpha photons from star-forming galaxies, revealing IGM effects dominate Lyman-alpha observability at high redshifts, while galactic outflows become more important at lower z.

The overlay for this one is here:

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

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Disentangling the galactic and intergalactic components in 313 observed Lyman-alpha line profiles between redshift 0 and 5" by Siddhartha Gurung-López (Universitat de València, Spain) and 7 others based in Spain and Germany.

doi.org/10.33232/001c.160706

April 17, 2026, 7:19 am 1 boosts 0 favorites

The fourth paper this week, also published on Friday 17th April is “Using Symbolic Regression to Emulate the Radial Fourier Transform of the Sérsic Profile for Fast, Accurate and Differentiable Galaxy Profile Fitting” by Tim B. Miller (Northwestern University, USA) and Imad Pasha (Yale University, USA). This one is published in the folder Instrumentation and Methods for Astrophysics: it develops an emulator for galaxy profile fitting in Fourier space, improving speed by 2.5 times with minimal accuracy loss, aiding in managing increasing data flow.

The overlay is here:

The finally accepted version of this paper can be found here and the Mastodon announcement follows:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Using Symbolic Regression to Emulate the Radial Fourier Transform of the Sérsic Profile for Fast, Accurate and Differentiable Galaxy Profile Fitting" by Tim B. Miller (Northwestern University, USA) and Imad Pasha (Yale University, USA)

doi.org/10.33232/001c.160755

April 17, 2026, 7:25 am 1 boosts 1 favorites

The fifth paper for this week is “The THESAN project: Lyman-alpha emitters as probes of ionized bubble sizes” by Meredith Neyer (MIT, USA) and 6 others based in the USA, Colombia, Canada, Japan and UK. The study uses THESAN simulations to explore how Lyman-alpha emitters (LAEs) trace ionized bubble sizes during the Epoch of Reionization, providing a framework for interpreting LAE surveys. This was published on Friday 17th April in the folder Astrophysics of Galaxies.

The overlay for this one is here:

You can find the authorized version of this paper on arXiv here and the Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "The THESAN project: Lyman-alpha emitters as probes of ionized bubble sizes" by Meredith Neyer (MIT, USA) and 6 others based in the USA, Colombia, Canada, Japan and UK.

doi.org/10.33232/001c.160756

April 17, 2026, 7:34 am 1 boosts 0 favorites

The sixth and final paper for this week is “Closed-Form Statistical Relations Between Projected Separation, Semimajor Axis, Companion Mass, and Host Acceleration” by Timothy D Brandt (Space Telescope Science Institute, USA). This was published on Friday 17th April in the folder Solar and Stellar Astrophysics. In this paper the author derives statistical relationships between radial velocity, a companion’s mass, and projected separation, useful for calculations requiring derivatives. The results are verified with empirical comparisons to existing literature.

The overlay for this one is here:

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

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Closed-Form Statistical Relations Between Projected Separation, Semimajor Axis, Companion Mass, and Host Acceleration" by Timothy D Brandt (Space Telescope Science Institute, USA)

doi.org/10.33232/001c.160757

April 17, 2026, 7:46 am 1 boosts 1 favorites

And that concludes this week’s update. I’ll do another one at the end of next week.

P.S. Just a reminder, for those of you into LinkedIn, that we now have a page there.

Weekly Update from the Open Journal of Astrophysics – 28/03/2026

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

Once again it’s time for the usual Saturday morning update of activity at the Open Journal of Astrophysics. Since the last update we have published a further eight papers, bringing the number in Volume 9 (2026) to 67 and the total so far published by OJAp up to 515.

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”Constraining Brown Dwarf Desert Formation Mechanisms through Bayesian Statistical Comparison of Observed and Simulated Populations” by Behrooz Karamiqucham (College of Charleston, USA). This paper was published on Tuesday March 24th in the folder Earth and Planetary Astrophysics. It presents a Bayesian statistical analysis exploring why brown dwarf companions are rarely found at orbital separations <5 AU. The results suggest that brown dwarfs form at wider separations then migrate.

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: "Constraining Brown Dwarf Desert Formation Mechanisms through Bayesian Statistical Comparison of Observed and Simulated Populations" by Behrooz Karamiqucham (College of Charleston, USA)

doi.org/10.33232/001c.159460

March 24, 2026, 7:10 am 1 boosts 1 favorites

The second paper for this week, also published on Tuesday March 24th, but in the folder Astrophysics of Galaxies, is “JWST observes the assembly of a massive galaxy at z ~ 4” by Aayush Saxena (University of Oxford, UK) and 20 others (based in the UK, Europe, USA, Brazil, Japan and China). The paper presents observations of radio galaxy TGSSJ1530+1049, revealing it as part of a dense structure of emitting objects likely to merge to form a massive galaxy within a few Gyr.

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: "JWST observes the assembly of a massive galaxy at z ~ 4" by Aayush Saxena (University of Oxford, UK) and 20 others (based in the UK, Europe, USA, Brazil, Japan and China)

doi.org/10.33232/001c.159461

March 24, 2026, 7:25 am 1 boosts 1 favorites

Next one up, the third paper of the week, also published on Tuesday March 24th in the folder Astrophysics of Galaxies, is “The dawn is quiet II: Gaia XP constraints on the Milky Way’s proto-Galaxy from very metal-poor MDF tails” by Boquan Chen (Ohio State U., USA), Matthew D. A. Orkney (Universitat de Barcelona, Spain), Yuan-Sen Ting (Ohio State U.) & Michael R. Hayden (U. Oklahoma, USA). The paper aegues that the Milky Way’s metallicity distribution suggests that its early evolution involved a moderate gas reservoir, sustained by weak continuous inflow, and star formation efficiency similar to the present value.

The overlay for this one is here:

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

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "The dawn is quiet II: Gaia XP constraints on the Milky Way’s proto-Galaxy from very metal-poor MDF tails" by Boquan Chen (Ohio State U., USA), Matthew D. A. Orkney (Universitat de Barcelona, Spain), Yuan-Sen Ting (Ohio State U.) & Michael R. Hayden (U. Oklahoma, USA)

doi.org/10.33232/001c.159462

March 24, 2026, 7:41 am 1 boosts 1 favorites

The fourth paper this week, published on Wednesday 25th March 2026 in the folder High-Energy Astrophysical Phenomena is “Shaping the diffuse X-ray sky: Structure, Variability and Visibility” by Philipp Girichidis (Heidelberg U., Germany) and 7 others based in Germany, USA, Austria and Italy. The paper argues that the X-ray properties of the Local Bubble (LB), a low-density cavity in the solar neighborhood reveal that supernova events significantly influence X-ray emissions, which show pronounced temporal variability

The overlay is here:

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

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Shaping the diffuse X-ray sky: Structure, Variability and Visibility" by Philipp Girichidis (Heidelberg U., Germany) and 7 others based in Germany, USA, Austria and Italy

doi.org/10.33232/001c.159505

March 25, 2026, 8:40 am 1 boosts 0 favorites

The fifth paper this week, also published on Wednesday 25th March 2026, is “Graph-Based Light-Curve Features for Robust Transient Classification” by Jesús D. Petro-Ramos David J. Ruiz-Morales, David Sierra Porta (Universidad Tecnológica de Bolívar, Colombia). This paper, which is in the folder Instrumentation and Methods for Astrophysics, uses graph-based representations of astronomical light curves for transient classification, achieving competitive multiclass performance, highlighting the potential of visibility graphs as a survey-agnostic tool for classifying time series.

This is the overlay:

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

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Graph-Based Light-Curve Features for Robust Transient Classification" by Jesús D. Petro-Ramos David J. Ruiz-Morales, David Sierra Porta (Universidad Tecnológica de Bolívar, Colombia)

doi.org/10.33232/001c.159506

March 25, 2026, 8:57 am 1 boosts 1 favorites

The sixth paper this week is “Redshift-Frame Systematics and Their Impact on the Hubble Constant from Pantheon+ Supernovae” by Said Laaroua (Santa Rosa Junior College, USA)This was published on Thursday 26th March in the folder Cosmology and Nongalactic Astrophysics. The study analyzes redshift-frame transformations in the Pantheon+ Type Ia supernova sample, finding a negligible shift in the Hubble constant, thus limiting redshift-frame systematics.

The overlay is here:

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

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Redshift-Frame Systematics and Their Impact on the Hubble Constant from Pantheon+ Supernovae" by Said Laaroua (Santa Rosa Junior College, USA)

doi.org/10.33232/001c.159558

March 26, 2026, 7:22 am 1 boosts 0 favorites

The penultimate, that is to say the seventh, paper for this week is “Why Machine Learning Models Systematically Underestimate Extreme Values II: How to Fix It with LatentNN” by Yuan-Sen Ting (Ohio State University, USA). The paper introduces LatentNN, a method that reduces attenuation bias in neural networks by optimizing network parameters and latent input values, improving inference in low signal-to-noise astronomical data; the code is available here. This article was published on Thursday 26th March 2026 in the folder Instrumentation and Methods for Astrophysics

The overlay for this one is here:

The official version of this paper can be found here. This is the Mastodon announcement:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Why Machine Learning Models Systematically Underestimate Extreme Values II: How to Fix It with LatentNN" by Yuan-Sen Ting (Ohio State University, USA)

doi.org/10.33232/001c.159559

March 26, 2026, 7:36 am 2 boosts 1 favorites

And finally for this week, published yesterday (Friday 27th March 2026) in the folder Astrophysics of Galaxies, we have “Catalog of Mock Stellar Streams in Milky Way-Like Galaxies” by Colin Holm-Hansen, Yingtian Chen and Oleg Y. Gnedin (University of Michigan, USA).

Here is the overlay for this one:

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

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Catalog of Mock Stellar Streams in Milky Way-Like Galaxies" by Colin Holm-Hansen, Yingtian Chen and Oleg Y. Gnedin (University of Michigan, USA)

doi.org/10.33232/001c.159598

March 27, 2026, 8:44 am 1 boosts 1 favorites

And that concludes the update for this week.

You will have observed that this week’s papers cover five of the six main categories on astro-ph. We haven’t yet managed to cover all six in a week – we only missed Solar and Stellar Astrophysics this time!