Weekly Update from the Open Journal of Astrophysics – 30/05/2026

It’s Saturday once 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 four papers, bringing the number in Volume 9 (2026) to 114 and the total so far published by OJAp up to 562.

I will continue to include the posts made on our Mastodon account (on Fediscience); these announcements also show the DOI for each paper.

The first paper to report this week, published on Monday 25th May is “Little Red Dot – Host Galaxy = Black Hole Star: A Gas-Enshrouded Heart at the Center of Every Little Red Dot” by Wendy Q. Sun (MIT, USA) and 32 others from around the world. This study presents evidence that “black hole stars” (BH*), early stages of black hole growth, power Little Red Dots (LRDs) and every massive black hole may have been a BH*.

The overlay for this paper is here

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

https://fediscience.org/@OJ_Astro/116633975428093674

The second paper for this week, also published on Monday 25th May but in the folder Cosmology and Nongalactic Astrophysics, is “Catalog-based detection of unrecognized blends in deep optical ground based imaging” by Shuang Liang (Stanford U., USA) and Prakruth Adari & Anja von der Linden (Stony Brook U., USA) on behalf of the LSST Dark Energy Science Collaboration. The study uses machine learning to detect unrecognized blends in deep ground-based imaging, improving sample purity and potentially enhancing accuracy in future cosmological surveys.

The overlay for this one is here:

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

https://fediscience.org/@OJ_Astro/116634039240557325

Next one up, the third paper of the week, published on Tuesday 26th May in the folder Cosmology and Nongalactic Astrophysics is “Control variates from Eulerian and Lagrangian perturbation theory: Application to the bispectrum” by Nickolas Kokron and Shi-Fan Chen (Institute for Advanced Study, Princeton, USA). This paper hexplores the use of control variates in cosmological simulations, introducing a new ‘shifted control variate’ that improves precision and enables accurate bispectrum emulators, aiding in cosmology modeling.

The overlay for this one is here:

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

https://fediscience.org/@OJ_Astro/116594304124291605

The fourth and final paper this week, also published on Tuesday 26th May is “How precisely can we measure the ages of subgiant and giant stars?” by Cheyanne Shariat, Kareem El-Badry and Soumyadeep Bhattacharjee (California Institute of Technology, USA). This article, published in the folder Solar and Stellar Astrophysics, is about testing the accuracy of stellar age estimates from recent catalogs, finding that spectroscopic metallicities provide reliable subgiant ages, while photometric ages underestimate uncertainties. Accurate chemical abundance measurements are essential.

The overlay is here:

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

https://fediscience.org/@OJ_Astro/116639604621500984

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

#arXiv250316680v2 #arXiv251007375v2 #arXiv251008675v4 #arXiv260120929v2 #AstrophysicsOfGalaxies #bispectrum #blendedImages #controlVariates #cosmicShear #cosmologicalSimulations #CosmologyAndNonGalacticAstrophysics #DiamondOpenAccess #DiamondOpenAccessPublishing #LSSTDarkEnergyScienceCollaboration #OpenAccess #OpenAccessPublishing #SolarAndStellarAstrophysics #VeraCRubinObservatory #weakGravitationalLensing

Weekly Update from the Open Journal of Astrophysics – 25/04/2026

So here we are again, on a Saturday morning, with another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further five papers, bringing the number in Volume 9 (2026) to 87 and the total so far published by OJAp up to 535.

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 “Bayesian Cosmic Void Finding with Graph Flows” by Leander Thiele (U. Tokyo, Japan). This was published on Monday 20th April in the folder Cosmology and Nongalactic Astrophysics. The paper presents a method using a deep graph neural network to identify cosmic voids in sparse galaxy surveys, improving upon traditional deterministic algorithms by considering the problem’s probabilistic nature. The overlay is here:

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

https://fediscience.org/@OJ_Astro/116435864086025246

The second paper for this week, published on Wednesday 22nd April in the folder Astrophysics of Galaxies, is “Sifting for a Stream: The Morphology of the 300S Stellar Stream” by Benjamin Cohen (U. Chicago, USA) and 20 others distributed around the world. This study analyzes the morphology of the $300S$ stellar stream, revealing three density peaks, a possible gap, and a kink, suggesting significant influence from the Large Magellanic Cloud on its structure.

The overlay for this one is here:

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

https://fediscience.org/@OJ_Astro/116447005556180402

Next one up, the third paper of the week, is “IRMaGiC: Extending Luminous Red Galaxy Selection into the Infrared with Joint Rubin Observatory’s Large Survey of Space Time and Roman’s High Latitude Imaging Survey” by Zhiyuan Guo & Chris. W. Walter (Duke U., USA) and Eli S. Rykoff (Stanford U., USA) on behalf of the LSST Dark Energy Science Collaboration. This was published on Wednesday April 22nd in the folder Cosmology and Nongalactic Astrophysics. The paper introduces IRMaGiC, an algorithm that improves the selection and redshift estimation of Luminous Red Galaxies (LRGs) by incorporating infrared data, enhancing future cosmological surveys.

The overlay for this one is here:

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

https://fediscience.org/@OJ_Astro/116447067337351283

The fourth paper this week, published on Thursday April 23rd, is “The Diagnostic Temperature Discrepancy as Evidence for Non-Maxwellian Coronal Electrons” by Victor Edmonds (Final Stop Consulting, USA). This paper, in the folder Solar and Stellar Astrophysics, presents two methods of measuring electron temperature in the quiet solar corona yielding different results, suggesting non-Maxwellian electron velocity distributions may be responsible for the discrepancy.

The overlay is here:

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

https://fediscience.org/@OJ_Astro/116452775389963618

The fifth and final paper for this week was published on Friday 24th April in the folder Astrophysics of Galaxies. The title is “Galaxy evolution in the post-merger regime. IV – The long-term effect of mergers on galactic stellar mass growth and distribution” by Sara L. Ellison (U. Victoria, Canada) and Leonardo Ferreira (Universidade Federal do Rio Grande, Brazil). This study uses a large sample of post-merger galaxies to demonstrate that galaxy mergers trigger significant and extended stellar mass growth in their central regions, independent of stellar population modelling.

The overlay is here:

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

https://fediscience.org/@OJ_Astro/116458316824739014

The overlay for this one is here:

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

https://fediscience.org/@OJ_Astro/116458316824739014

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

P.S. Thanks to the efforts of a member of our Editorial Board, the Open Journal of Astrophysics now has a Wikipedia page.

#300SStellarStream #arXiv250621410v2 #arXiv251121512v2 #arXiv260114554v2 #arXiv260214630v2 #arXiv260310040v3 #AstrophysicsOfGalaxies #BayesianMethods #CosmicVoids #CosmologyAndNonGalacticAstrophysics #DiamondOpenAccess #DiamondOpenAccessPublishing #EarthAndPlanetaryAstrophysics #GAIA #galaxyEvolution #galaxyFormation #galaxyMergers #InstrumentationAndMethodsForAstrophysics #IntergalacticMedium #IRMaGiC #LargeMagellanicCloud #LSST #LSSTDarkEnergyScienceCollaboration #MilkyWay #OpenAccess #OpenAccessPublishing #SolarAndStellarAstrophysics #SolarCorona #VeraCRubinObservatory #wikipedia