I’ve been remiss in not passing on significant news that involves former colleagues at Cardiff University and Sussex University, so I thought I would remedy that lapse today. A few weeks ago it was announced that NASA has selected a far-infrared space telescope called PRIMA as the first in a new series of missions to be launched around 2033. The mission now enters a Phase B study.
In a nutshell, PRIMA (PRobe far-Infrared Mission for Astrophysics) is a far-infrared observatory based around a 1.8-m diameter telescope, cryogenically-cooled (to 4.5 K). It includes both a sensitive wideband spectrometer FIRESS, and a multi-band spectrophotometric imager /polarimeter PRIMAger. PRIMA’s sensitivity unlocks the potential of the far-IR waveband to advance astrophysics across a broad range of topics spanning from galaxy and dust evolution in the early universe to the formation of planets and planetary atmospheres. FIRESS offers full-band instantaneous coverage from 24 to 235 μm in two modes. The low-res mode offers R~100 with long slits, while the high-resolution mode offers R up to 4,400 × (112 μm / λ) in smaller fields. PRIMAger offers rapid R=8 hyperspectral imaging with continuous coverage from 25 to 84 μm, and imaging polarimetry in 4 bands from 90 to 235 μm.
Although a NASA mission, several UK institutions are involved in PRIMA: Cardiff University, Imperial College London, the University of Sussex, and RAL Space. Cardiff University’s involvement is primarily (geddit?) in instrument development (see here) and former colleague at Sussex, Seb Oliver, will lead the UK’s overall contribution.
I wish everyone involved all the best for the planning, development and future operation of this mission. I will of course be long retired before it is launched!
It’s Saturday again, so it’s time for another 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 237 and the total so far published by OJAp up to 685.
I continue to include the posts made on our Mastodon account (on Fediscience); these announcements also contain a clickable form of the DOI for each paper. Our Mastodon account has regular updates and other announcements from OJAp too, including posts from the OJAp blog.
The first new paper this week was published on Monday 5th October in the folder Solar and Stellar Astrophysics. The title of the paper is “Diameters and Temperatures VII: High-angular resolution measurements of Solar-type stars with the CHARA Array” and it isby Tabetha Boyajian (Louisiana State University, USA) and 10 others based in the USA and Australia. This study uses interferometric measurements to determine precise characteristics of 27 nearby solar-type stars, including their radii, effective temperatures, and luminosities. The findings represent benchmarks for testing stellar evolutionary theory.
The overlay for this one is here:
You can find the officially accepted version on arXiv here and the announcement on Fediverse here:
New Publication at the Open Journal of Astrophysics: "Diameters and Temperatures VII: High-angular resolution measurements of Solar-type stars with the CHARA Array" by Tabetha Boyajian (Louisiana State University, USA) and 10 others based in the USA and Australia.
New Publication at the Open Journal of Astrophysics: "The jet-shaped pipe morphology in planetary nebulae and core-collapse supernova remnants" by Jessica Braudo and Noam Soker (Technion, Israel)
New Publication at the Open Journal of Astrophysics: "Balancing bias, baryons, and scale cuts in LSST 3x2pt analysis" by Ottavia Truttero (U. Edinburgh, UK) and 5 others on behalf of the The LSST Dark Energy Science Collaboration
New Publication at the Open Journal of Astrophysics: "High-Precision Differential Radial Velocities of C3PO Wide Binaries: A Test of Modified Newtonian Dynamics (MOND)" by Serat M. Saad and Yuan-Sen Ting (Ohio State University, USA)
New Publication at the Open Journal of Astrophysics: "Simulating the jittering-jets explosion mechanism: circum-jet rings account for observed core-collapse supernova remnant morphologies" by Muhammad Akashi & Noam Soker (Technion, Israel)
The sixth paper of the week is “Radio Continuum Study of One of the Brightest Large Magellanic Cloud Supernova Remnant N 132D” by Rami Z. E. Alsaberi (Western Sydney U. Australia) and 7 others. This was the first of three papers published on Friday 9th October, and it is in the folder High-Energy Astrophysical Phenomena. This one presents a radio continuum analysis of the Large Magellanic Cloud supernova remnant N 132D, revealing insights into its magnetic field structure, energetic properties, and particle acceleration.
The officially-accepted version of this paper is on arXiv here and the Mastodon announcement on the fediverse here:
New Publication at the Open Journal of Astrophysics: "Radio Continuum Study of One of the Brightest Large Magellanic Cloud Supernova Remnant N 132D" by Rami Z. E. Alsaberi (Western Sydney U. Australia) and 7 others
The seventh paper of the week is “New Signs Pointing Toward a Correlation Between Astrophysical Neutrinos and Radio Flares” by Yjan Gordon (U. Wisconsin-Madison), Peter S. Ferguson (U. Washington), Eric J. Hooper & Michael N. Martinez (U. Wisconsin-Madison); all in the USA. This was also published on Friday 7th October, but in the folder Astrophysics of Galaxies. It is very topical, in the light of the award of this year’s Nobel Prize for Physics to Francis Halzen for his work on IceCube. The paper explains how data from VLASS and IceCube Neutrino Observatory reveal a correlation between radio variability and astrophysical neutrino detection, suggesting radio flares contribute to about 13% of astrophysical neutrinos detected by IceCube.
The overlay is here:
The officially accepted version is on arXiv here and the Mastodon announcement here:
New Publication at the Open Journal of Astrophysics: "New Signs Pointing Toward a Correlation Between Astrophysical Neutrinos and Radio Flares" by Yjan Gordon (U. Wisconsin-Madison), Peter S. Ferguson (U. Washington), Eric J. Hooper & Michael N. Martinez (U. Wisconsin-Madison); all in the USA
New Publication at the Open Journal of Astrophysics: "Spectroscopic follow-up of compact object binary candidates from Gaia DR3: White dwarfs, neutron stars, black holes, and the parallax zeropoint" by Kareem El-Badry (Caltech, USA) and an international cast of 14 others.
That concludes this week’s update. We’re still on target to publish over 300 papers and reach the 750 mark by the end of the year. I’ll do another update next week.
Last night, as advertised, we held our Space Week Event at Maynooth University. This has been running for a few years now but last night was the first time we have included planetarium shows in our inflatable dome shows alongside the usual short lectures.
That resulted in much greater organizational challenges, as the space in the dome is quite limited so we had to split those wanting to attend a show into manageable groups, and that in turn meant quite a few people moving in and out of the lecture theatre to and from the dome, which were in different locations. It all went off well, though.
The weather last night was inclement, cold and with heavy rain, but despite that we had about 250 in the lectures. There were lots of young children, some perhaps as young as five years old, and I was very impressed by the quality of the questions they asked at the end of the talks and in the coffee break.
We had a last-minute change of order of lectures because one of our speakers was stuck in traffic on the way to campus. I was promoted to No. 2 in the running order instead of No. 4, which I was quite happy about because it meant I finished earlier. After it was all over we adjourned to O’Neill’s for a pint or two.
Thanks to everyone from the Department of Physics who participated in the preparations for, and running of, the event, and to all the people who came long and made it such fun!
P.S. The resemblance between the title of the event at the title of this blog is purely coincidental.
There’s a short article on arXiv by astronomer Luigi Rolly Bedin with the title The Preprint Evolution: The Rise of Unreviewed Drafts on arXiv and its Implications for Astronomy and abstract:
The arXiv preprint server originally democratized astronomical research by digitizing the circulation of early manuscripts and removing the financial barriers of journal subscriptions. However, a system designed for the lower publication volumes of the 1990s has fractured under modern research output. Today, the sheer volume of unreviewed manuscripts—often tagged as “submitted”, “under review”, or “comments welcome” imposes a severe cognitiv “tax” on the community. Researchers are forced to track multiple, unvetted versions of the same work, creating a massive redundant workload. This practice also bypasses the blinded peer-review process by establishing premature precedence, and it takes a heavy toll on early-career researchers. The pressure to rapidly post unvetted results stifles independent research, pushing young scientists toward massive mainstream collaborations where individual creativity gets lost. In this Short Communication, I analyze a decade of astro-ph metadata to quantify this trend. To safeguard both researchers’ time and research freedom, I propose bifurcating submissions into two separate streams. Level-1 (peer-reviewed science) would host peer-reviewed science (accompanied by a journal acceptance or final DOI), while Level-2 (pre-review drafts) would be reserved for discussion drafts. This distinction would remove the unfair advantage of establishing false precedence through drafts and drastically cut the daily reading burden by allowing researchers to opt out of tracking unvetted versions.
arXiv:2609.35787
I’ve mentioned this paper on this blog because a couple of readers commented about it on a post earlier this week (here and here) I’ll leave it to readers to decide for themselves what they think about the suggestion of having a two-tier arXiv as described in the abstract. A rebuttal has been posted on arXiv here.
For myself I’ll just say that I think that, for such a short paper, it contains a very large number of unsubstantiated claims. I don’t doubt that the number of pre-review submissions has increased over the years, but are researchers really “forced to track multiple, unvetted versions of the same work, creating a massive redundant workload”? Is it really the case that the existence of unrefereed articles on arXiv “stifles independent research, pushing young scientists toward massive mainstream collaborations where individual creativity gets lost”? Where is the evidence for this claim? The claim of a `severe cognitive “tax” on the community’ seems a huge stretch to me too. If you really don’t want to read unrefereed articles on arXiv then you can just ignore those that don’t have a journal reference in their metadata.
I wrote a piece about preprints some time ago here. In it I tried to explain how preprints were initially used to circulate refereed work in advance of the final printed version being available, which often took many months after acceptance. Back in the old days these were usually produced by institutions with a distinctive design, logo, etc which gave them a professional look, which made it easier to distinguish `serious’ papers from crank material (which was also in circulation). This also suggested that some internal refereeing inside an institution had taken place before an “official” preprint was produced, lending it an air of trustworthiness. Smaller institutions couldn’t afford all this, so were somewhat excluded from the preprint business.
With the arrival of the arXiv the practice of circulating hard copies of preprints in astrophysics gradually died out, to be replaced by ever-increasing numbers of electronic articles. The arXiv does have some gatekeeping – in the sense there are some controls on who can deposit a preprint there – but it is far easier to circulate a preprint now than it was.
(I am, incidentally, very surprised that this article – with only reference (to itself) and no evidence to support its claims – passed the arXiv moderation process for astro-ph, but there you go…
Anyway, it is still the case that big institutions and collaborations insist on quite strict internal refereeing before publishing a preprint – and some even insist on waiting for a paper to be accepted by a journal before adding it to the arXiv – but there’s no denying that among the wheat there is quite a lot of chaff, some of which attracts media coverage that it does not deserve. It is also the case that some articles that have passed peer review are flawed in crucial ways not spotted by referees. No system that is operated by human beings will ever be flawless, and peer review is no different. Not everything in “Tier 1” is perfect.
The most important thing is for science to advance. Circulating a paper in advance of review can help to achieve that. I have very often found that comments from other researchers reading the arXiv version supply comments and suggestions far more useful than one gets from a journal reviewer. Sometimes they can spot a fundamental flaw missed by a referee. If you put your paper on arXiv ahead of official peer review you will subject it to an additional level of scrutiny, increasing the chance that the final version will turn out to be a useful contribution to the literature.
Nowadays, in astrophysics, the single most important point of access to scientific literature is through the arXiv, which is why the Open Journal of Astrophysics was set up as an overlay journal to provide a level of rigorous peer review for preprints, not only to provide a sort of quality mark but also to improve the paper through the editorial process. There’s your Tier 1 for you.
P.S. I didn’t think of this at the time but one of the reasons that the fraction of unreviewed preprints is increasing is simply that people are not very good at updating their arXiv entry when a paper is actually published. I noticed this with Euclid papers, for example, which are generally posted on arXiv as preprints and subsequently published in A&A. It was noticeable, however, that some authors do not update the arXiv metadata after acceptance.
Just to mention the announcement of this year’s Nobel Prize for Physics will take place tomorrow (Tuesday, October 6th,2026). I must remember to make sure my mobile phone is fully charged so I can be easily reached, although I am likely to be lecturing when the announcement is made.
I was, however, a guest of the Nobel Foundation rather than a prizewinner, so my medal is made of chocolate rather than gold. I think after 20 years the chocolate is now inedible, but it serves as a souvenir of a very nice weekend in Stockholm! Sadly one of the Laureates whose award we were celebrating passed away recently.
I drew a blank in 2023 when “attosecond light pulses” were the topic and was completely wrongfooted when the 2024 Nobel Prize for Physics was awarded to John J. Hopfield and Geoffrey E. Hinton “for foundational discoveries and inventions that enable machine learning with artificial neural networks”. I didn’t see that one coming at all. Last year’s went to John Clarke, Michel H. Devoret and John M. Martinis “for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit”.
I really have no idea who will win it this year, but I’ll suggest that there’s still an outside chance for Michael Berry and Yakir Aharonov for their work on the geometric phase, although if they were going to win they would probably have done so by now.
Feel free to make your own predictions through the comments box below! To find out who the lucky winners you’ll have to wait for the announcement, around about 10.45 (UK/Irish time) on Tuesday morning. I’ll update this post when the wavefunction has collapsed.
Update: I’m not often right but I was wrong again.
I’m a little surprised to see this going to just one person, but there you are.
It’s Saturday again, so it’s time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further 13 papers, including one correction to an article already published, bringing the number in Volume 9 (2026) to 229 and the total so far published by OJAp up to 677. This would have been a busy week even without the clutch of four MEGATRON papers announced on Wednesday!
I continue to include the posts made on our Mastodon account (on Fediscience); these announcements also contain a clickable form of the DOI for each paper. Our Mastodon account has regular updates and other announcements from OJAp too, including posts from the OJAp blog.
The first new paper this week was published on Tuesday 28th September in the folder Solar and Stellar Astrophysics. The title is “Phlegethon: a fully compressible magnetohydrodynamic code for simulations in stellar astrophysics” and it is by G. Leidi (Heidelberger Institut für Theoretische Studie, Germany) and 14 others. PHLEGETHON is a magnetohydrodynamic code designed for multidimensional simulations in stellar astrophysics, capable of modeling a wide range of dynamical processes in stars. It is publicly accessible online.
The overlay for this one is here:
You can find the officially accepted version on arXiv here and the announcement on Fediverse here:
New Publication at the Open Journal of Astrophysics: "Phlegethon: a fully compressible magnetohydrodynamic code for simulations in stellar astrophysics" by G. Leidi (Heidelberger Institut für Theoretische Studie, Germany) and 14 others.
New Publication at the Open Journal of Astrophysics: "The impact of source and survey modelling on the connection between [O III] emitters and Ly-α forest transmission at z ~ 6" by Luke Conaboy (U. Nottingham, UK) and 5 others based in the UK, India and Germany.
Next we have four related papers produced by the MEGATRON Project, led by Harley Katz (U. Chicago) and Martin Rey (U. Bath, UK), Corentin Cadiou (IAP Paris, France). These were all published on Wednesday 30th September in the folder Astrophysics of Galaxies.
I mentioned this in a separate blog post here, so I won’t describe them in detail again here. Here are the four overlays:
The Mastodon announcement for these is in the form of a thread:
Today we have published four related papers produced by the MEGATRON Project, led by Harley Katz (U. Chicago) and Martin Rey (U. Bath, UK), Corentin Cadiou (IAP Paris, France)
These articles are announced in the following thread:
The four papers can be found on arXiv here, here, here and here.
The four MEGATRON papers were not the only ones published on Wednesday 30th September, however. We published “The Chirp-Mass Ladder: A New Rung Emerges” by Vaibhav Tiwari (U. Birmingham, UK) in the folder High-Energy Astrophysical Phenomena on that day too. This paper presents an analysis of 256 binary black-hole (BBH) events, suggesting a hierarchical merger scenario to explain the structured mass distribution, and encouraging further investigation into hierarchical mergers’ role in the BBH population. The overlay for this is here:
The accepted version of this one can be found on the arXiv here and the Mastodon announcement here:
New Publication at the Open Journal of Astrophysics: "Kinematics of the Weak Cool-Core Cluster A3571 Observed with XRISM: Low Cooling Rate Balanced by Low Heating Rate?" by Hannah McCall (U. Chicago, USA) and 12 others based around the world.
We now have four papers all published on Friday 2nd October (i.e. yesterday).
The first of this batch is “Analytical weak-lensing shear response of galaxy model fitting” by Xiangchong Li (Brookhaven National Laboratory, USA). This is in the folder marked Cosmology and Nongalactic Astrophysics: it explores how galaxy model fitting responds to weak-lensing shear distortions using a new algebraic system, quintuple numbers, within the AnaCal framework, keeping multiplicative bias low.
The overlay is here:
The officially-accepted version of the paper can be found on arXiv here and the Fediverse announcement here:
New Publication at the Open Journal of Astrophysics: "Analytical weak-lensing shear response of galaxy model fitting" by Xiangchong Li (Brookhaven National Laboratory, USA)
New Publication at the Open Journal of Astrophysics: "Evidence for inefficient dust production in a massive, metal-rich galaxy at z=7.13 uncovered by JWST and ALMA" by Kasper E. Heintz (Cosmic Dawn Center, Copenhagen, Denmark) and 19 others in Europe, UK and USA.
The 11th paper of the week is “Starbursts hiding in the main sequence: a pathway toward quenching?” by Florent Renaud (Observatoire Astronomique de Strasbourg, France) and 12 others based in France and UK. This article explores the “starbursts in the main sequence” (SBMSs) that intermittently appear in galaxy evolution, attributing their existence to earlier stellar mass assembly and frequent mergers. It was published on Friday 2nd October 2026, in the folder Astrophysics of Galaxies.
The overlay is here:
The officially accepted version is on arXiv here and the Mastodon announcement here:
New Publication at the Open Journal of Astrophysics: "Starbursts hiding in the main sequence: a pathway toward quenching?" by Florent Renaud (Observatoire Astronomique de Strasbourg, France) and 12 others based in France and UK.
New Publication at the Open Journal of Astrophysics: "Ring Position Angles and Spin in M87* and Sgr A*" by Nicholas S. Conroy (U. Illinois at Urbana-Champaign, USA) and 6 others all based in the USA.
And finally, on Monday 28th September we announced one (minor) correction to a previously published article. The overlay of the correction notice is here:
Correction Notice issued at the Open Journal of Astrophysics: "CORRECTION – TDCOSMO XXVI: Uniform Lens Modeling of Eight Doubly Imaged Quasars" by Brady et al. (originally published 7th August 2026).
The corrected version of this paper can be found on arXiv here.
That concludes this week’s update. As things are going we seem likely to publish over 300 papers this year, and may reach the 750 mark by the end of the year too. I’ll do another update next week.
Today we published four papers at the Open Journal of Astrophysics all related to the Megatron Project which is co-led by Martin Rey of the University of Bath (UK), Harley Katz of the University of Chicago (USA) and Corentin Cadiou of the Institut d’Astrophysique de Paris in France. I will include this quartet in my regular weekly update on Saturday but there is a press release accompanying these publications so I thought I’d splash them a bit here too.
I’ll show the overlays on Saturday but in the meantime here are some pretty graphics from three of the papers:
New simulations connect the first stars to cosmic fingerprints still visible today
International MEGATRON project links space telescope observations of the infant Universe with the chemical fossil record of the Milky Way.
Researchers have used some of the most detailed simulations yet of the early Universe to investigate how the first stars and galaxies formed.
Led by researchers at the University of Bath, alongside collaborators at the University of Chicago in the US and the Institut d’Astrophysique de Paris in France, the MEGATRON project uses advanced simulations to explore how the first stars and galaxies lit up the previously dark cosmos and enriched it with the chemical elements that would later become the building blocks of everything around us.
Published today in the Open Journal of Astrophysics, four studies from the MEGATRON project combine cutting-edge cosmological simulations with sophisticated models of radiation, chemistry and galaxy formation. Together, these constitute the collaboration’s first substantial body of published results, with further papers expected to follow.
The findings from the study of the first stars show that accurately capturing the interplay between starlight, gas and newly forged elements is essential for connecting two previously separate views of the early Universe: observations of young galaxies by the James Webb Space Telescope (JWST) and the chemical clues preserved in ancient stars in and around the Milky Way – the galaxy that contains our Solar System.
JWST provides a direct view of galaxies in the infant Universe, while ancient stars act as a fossil record of cosmic history. By studying the chemical fingerprints of these ancient stars, astronomers can reconstruct the properties of the first stars and trace how they enriched the cosmos with the first chemical elements.
The simulations follow the evolution of a young galaxy that will eventually grow into a system similar in mass to the Milky Way. Using advanced computer models that simultaneously track the movement of gas, the propagation of starlight and the evolution of chemical concentrations, the team investigated how stars shape the gas in and around galaxies over billions of years.
The study suggests that simplified models may underestimate the influence of stellar radiation and complex chemical processes on the gas surrounding galaxies. By modelling these effects at exceptionally high resolution, the team resolved structures in the gas that are not captured by simpler models, helping to improve predictions for current and future astronomical observations.
A direct glimpse of the infant cosmos
Dr Martin Rey from the Department of Physics at the University of Bath and a lead contributor to the MEGATRON collaboration, said: “The James Webb Space Telescope gives us a direct glimpse of the infant cosmos, while stellar archaeology allows us to study the relics of those earliest times in our own Galactic neighbourhood. MEGATRON provides a physical bridge between the two.”
The simulations begin with pristine gas containing no heavy elements, mirroring conditions shortly after the Big Bang. They then follow the birth of the first stars, the radiation they emit, the supernova explosions that mark their deaths and the dispersal of newly forged elements into subsequent generations of stars and galaxies.
Understanding this process is central to one of astronomy’s most fundamental questions: where the elements that make up today’s Universe came from.
Dr Rey said: “The elements that make our world and life possible – carbon, oxygen, iron and many others – were forged by stars. To understand where those elements came from, we need to understand how the first stars formed and enriched their surroundings. MEGATRON allows us to test these ideas directly by comparing detailed simulations with observations from JWST and the chemical fingerprints preserved in ancient stars.”
Looking ahead, the team plans to use MEGATRON to strengthen links between theory and emerging observational data. As JWST continues to transform our understanding of the earliest galaxies, large-scale stellar surveys will provide increasingly detailed information about ancient stars in and around the Milky Way.
Dr Rey and his colleagues at Bath are already developing the next generation of simulations. The project has been awarded 40 million processor hours on the UK’s national supercomputers, equivalent to running five million laptops in parallel for a year. These resources will enable simulations with higher resolution and more complete physical models, allowing even more direct comparisons with JWST observations and the chemical fossil record preserved in ancient stars.
“MEGATRON provides a common physical framework for interpreting two of astronomy’s most exciting new datasets: JWST’s view of the earliest galaxies and the stellar fossil record,” said Dr Rey. “Together, these complementary observations allow us to test competing models of the first stars in ways that weren’t previously possible.”
The MEGATRON project started in 2023 and is scheduled to run until 2030.
It’s time once more for another Saturday update of activity at the Open Journal of Astrophysics. Since the last update we have published a further eight papers, including one correction to an article already published, bringing the number in Volume 9 (2026) to 217 and the total so far published by OJAp up to 664. This is the third week running that we have published 7 new papers.
I continue to include the posts made on our Mastodon account (on Fediscience); these announcements also contain a clickable form of the DOI for each paper. Our Mastodon account has regular updates and other announcements from OJAp too, including posts from the OJAp blog.
The first paper this week was published on Monday 21st September in the folder Solar and Stellar Astrophysics. The title is “The Payne Zero Project I: Stellar Spectra from Physical Models in Seconds” and it is by Yuan-Sen Ting (Ohio State U., USA) and Elliot M. Kim (Cornell U., USA). The study introduces Payne Zero, a tool that reorganizes stellar spectra calculations for GPU-native synthesis, significantly speeding up the process and enabling direct physical fitting and atomic-data calibration at survey scale.
The overlay for this one is here:
You can find the officially accepted version on arXiv here and the announcement on Fediverse here:
New Publication at the Open Journal of Astrophysics: "The Payne Zero Project I: Stellar Spectra from Physical Models in Seconds" by Yuan-Sen Ting (Ohio State U., USA) and Elliot M. Kim (Cornell U., USA)
The second paper for this week, published on Tuesday 22nd September, is titled “RUBIES: The Evolution of the Ionization Parameter from 0 < z < 9” and is in the folder Astrophysics of Galaxies. The authors are Nikko Cleri (Penn State U., USA) and 12 others based in the USA, Switzerland and Germany. The article involves an examination of the time evolution of the ionization parameter in galaxies, finding that it increases with redshift and specific star formation rate, and decreases with stellar mass.
The overlay looks like this:
The official version of the paper can be found on arXiv here and the Fediverse announcement here:
New Publication at the Open Journal of Astrophysics: "RUBIES: The Evolution of the Ionization Parameter from 0 < z < 9" by Nikko Cleri (Penn State U., USA) and 12 others based in the USA, Switzerland and Germany
New Publication at the Open Journal of Astrophysics: "Kinematics of the Weak Cool-Core Cluster A3571 Observed with XRISM: Low Cooling Rate Balanced by Low Heating Rate?" by Hannah McCall (U. Chicago, USA) and 12 others based around the world.
New Publication at the Open Journal of Astrophysics: "The Simons Observatory: Development of a Pipeline to Detect Rapid Transients in Time-Ordered Data" by Justin Clancy (U. Melbourne, Australia) and 16 others from around the world.
The fifth paper of the week is “Fisher Forecasting for the DESC with Augur” by Paul Rogozenski (Carnegie Mellon U., USA) and 16 others on behalf of the The LSST Dark Energy Science CollaborationThis was also published on Wednesday 16th September, but in the folder Cosmology and Nongalactic Astrophysics. This paper introduces the Augur tool, designed to provide Fisher forecasts for cosmological inference for the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST).
The overlay for this one looks like this:
The officially-accepted version of this paper is on arXiv here and the Mastodon announcement on the fediverse here:
New Publication at the Open Journal of Astrophysics: "Fisher Forecasting for the DESC with Augur" by Paul Rogozenski (Carnegie Mellon U., USA) and 16 0thers on behalf of the The LSST Dark Energy Science Collaboration
The sixth paper of the week is “Profile Analysis of the Multiwavelength 2.1-year Oscillations of PG 1553+113” by Pablo Penil (Clemson U. USA) and 7 others based in the USA, Germany and Spain. This was also published on Wednesday 23rd September, in the Astrophysics of Galaxies. The study examines the oscillation profiles of blazar PG~1553+113, finding that its 2.1-year periodicity is not strictly sinusoidal and varies across energy bands.
The overlay is here:
The officially accepted version is on arXiv here and the Mastodon announcement here:
New Publication at the Open Journal of Astrophysics: "Profile Analysis of the Multiwavelength 2.1-year Oscillations of PG 1553+113" by Pablo Penil (Clemson U. USA) and 7 others based in the USA, Germany and Spain.
Our seventh, and last, new paper of the week is “Radial Pulsations in Polaris: A Secondary Science Application of Cherenkov Telescopes via Intensity Interferometry” by Km Nitu Rai (IISER, India), Prasenjit Saha (U. Zurich, Switzerland) and Subrata Sarangi (IUCAA, India). This study demonstrates how Cherenkov telescopes, typically unused during moonlit nights, can be used for advanced optical stellar measurements, particularly for characterizing bright stars such as Polaris.
The overlay is here:
The final version of this paper is on the arXiv here and the Mastodon announcement here:
New Publication at the Open Journal of Astrophysics: "Radial Pulsations in Polaris: A Secondary Science Application of Cherenkov Telescopes via Intensity Interferometry" by Km Nitu Rai (IISER, India), Prasenjit Saha (U. Zurich, Switzerland) and Subrata Sarangi (IUCAA, India)
Correction Notice issued at the Open Journal of Astrophysics: "CORRECTION: The Abundance of Thin Dwarf Galaxies: a Challenge for Cosmological Simulations" by Jose Benavides et al. (originally published 12th May 2026)
The corrected version of this paper can be found on arXiv here.
That concludes this week’s update. I’ll just add a mention of yesterday’s post announcing that the Open Journal of Astrophysics is a Q1 Journal. It will be interesting to see if that stimulates another increase in submissions. As things are going we seem likely to publish about 300 papers this year. I’ll also mention that an exciting development is in the pipeline for next week, but I can’t say more until it happens.
Today is a very busy teaching day, so I just have time to post a quick note to say that the Autumnal Equinox (in the Northern Hemisphere) takes place in the early hours of tomorrow morning, Wednesday 23rd September 2026, at 01:05 Irish Time (00:05 UTC). I don’t intend to be awake then, so I’m posting this now. Of course the Equinox will be later today rather than tomorrow for some of you, depending on your time zone. Of course for those of you in the Southern Hemisphere it will be the Spring (or Vernal) Equinox.
Although the term `equinox’ refers to a situation in which day and night are of equal length, which implies that it’s a day rather than a specific time, the astronomical equinox is more accurately defined by a specific event, i.e. when the plane defined by Earth’s equator passes through the centre of the Sun’s disk (or, if you prefer, when the centre of the Sun passes through the plane defined by Earth’s equator). Day and night are not necessarily exactly equal on the equinox, but they’re the closest they get. From now on days in the Northern hemisphere will be shorter than nights and they’ll get shorter still until the Winter Solstice on Monday 21st December 2026 at 11.50 pm Irish Time.
Many people take the autumnal equinox to be the end of summer. There is a saying in some quarters, however, that `Summer is Summer to Michaelmas Day’ (September 29th), which is not until next week. The weather has indeed been very nice in Maynooth for the first couple of days of term. The temperature reached 23°C yesterday!
It’s time once more for another Saturday update of activity at the Open Journal of Astrophysics. Since the last update we have published a further seven papers, bringing the number in Volume 9 (2026) to 209 and the total so far published by OJAp up to 656. This is the second week running that we have published 7 papers.
I continue to include the posts made on our Mastodon account (on Fediscience); these announcements also contain a clickable form of the DOI for each paper. Our Mastodon account has regular updates and other announcements from OJAp too.
The first paper this week was published on Monday 14th September in the folder Cosmology and Nongalactic Astrophysics. The title is “The Power of DESI for Photometric Redshift Calibration: A Case Study with KiDS-1000” and it is by Diana Blanco (UC Santa Cruz, USA) and 66 others distributed internationally. This study explores using the Dark Energy Spectroscopic Instrument (DESI) to calibrate photometric redshift distributions for gravitational lensing, which could improve understanding of dark energy and cosmic structure. In fact this paper was ready for publication a few months ago, but the first author left for another job before putting the final version on arXiv so it took a while to finish it.
The overlay for this one is here:
You can find the officially accepted version on arXiv here and the announcement on Fediverse here:
New Publication at the Open Journal of Astrophysics: "The Power of DESI for Photometric Redshift Calibration: A Case Study with KiDS-1000" by Diana Blanco (UC Santa Cruz, USA) and 66 others distributed internationally.
The second paper for this week, published on Tuesday 15th September in the folder Solar and Stellar Astrophysics, is “Exploration of groups and outliers in Gaia RVS stellar spectra with metric learning” by Yarden Eilat Bloch & Dovi Poznanski (Tel-Aviv U., Israel), Nick L. J. Cox & Emmanuel Bernhard (ACRI-ST, Grasse, France), Iain McDonald (U. Manchester, UK), Manuela Rauch (Know Center, GmbH, Graz, Austria), and Albert Zijlstra (Manchester). This article presents a new dataset and interactive portal that applies advanced techniques to analyze and visualize nearly a million spectra from the Gaia mission, potentially revealing undiscovered stellar phenomena.
The overlay looks like this:
The official version of the paper can be found on arXiv here and the Fediverse announcement here:
New Publication at the Open Journal of Astrophysics: "Exploration of groups and outliers in Gaia RVS stellar spectra with metric learning" by Yarden Eilat Bloch & Dovi Poznanski (Tel-Aviv U., Israel), Nick L. J. Cox & Emmanuel Bernhard (ACRI-ST, Grasse, France), Iain McDonald (U. Manchester, UK), Manuela Rauch (Know Center, GmbH, Graz, Austria), and Albert Zijlstra (Manchester)
New Publication at the Open Journal of Astrophysics: "XID+PRIMA, II: Stepping Through Hyperspectral Imaging to Deblend PRIMAger Beyond the Extragalactic Confusion Limit" by James M. S. Donnellan (U. Sussex, UK) and 12 others based in the UK, France, USA, and The Netherlands
The fourth paper of the week, also published on Wednesday 16th September but in the folder Astrophysics of Galaxies is “The Curious Case of Centaurus A: On the Subject of the Quenched satellites” by Sachi Weerasooriya (Carnegie Obs., USA) and 8 others based in the USA and Canada. This study investigates the lack of luminous satellite galaxies in Centaurus A’s inner regions, suggesting that AGN-driven thermal feedback could suppress star formation, affecting the survival and evolution of satellites
The overlay is here:
The officially-accepted version of the paper can be found on arXiv here and the Fediverse announcement here:
New Publication at the Open Journal of Astrophysics: "The Curious Case of Centaurus A: On the Subject of the Quenched satellites" by Sachi Weerasooriya (Carnegie Obs., USA) and 8 others based in the USA and Canada
New Publication at the Open Journal of Astrophysics: "Weak-lensing Shear-Selected Galaxy Clusters from the Hyper Suprime-Cam Subaru Strategic Program: III. A precision cosmological sample enabled by optical confirmation" by I-Non Chiu (National Cheng Kung U., Taiwan) and 11 others from around the world.
Last, but by no means least, we have our seventh paper of the week: “The Cosmological Simulation Code OpenGadget3 – Implementation of Self-Interacting Dark Matter” by Moritz S. Fischer (Donastia International Physics Center, Spain) and 9 others based in Germany, Italy, USA , Sweden and Denmark. This was published on Friday 18th September (i.e. yesterday) in the folder Instrumentation and Methods for Astrophysics. This paper discusses the use of OpenGadget3, a tool for simulating self-interacting dark matter (SIDM), and highlights its capabilities, performance, and areas for improvement.
The overlay is here:
The final version of this paper is on the arXiv here and the Mastodon announcement here:
That concludes this week’s update. At the rate we’re going we could well reach 300 by the end of the year, but we’ll just have to wait and see about that. I’ll do another next weekend.
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