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

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:

https://fediscience.org/@OJ_Astro/116395992732332356

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:

https://fediscience.org/@OJ_Astro/116396069424189312

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:

https://fediscience.org/@OJ_Astro/116418831864134501

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:

https://fediscience.org/@OJ_Astro/116418855010158656

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:

https://fediscience.org/@OJ_Astro/116418887225003954

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:

https://fediscience.org/@OJ_Astro/116418938017199814

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.

#arXiv250303824v4 #arXiv250820266v2 #arXiv250914875v2 #arXiv251018946v2 #arXiv251109644v2 #arXiv260114688v2 #AstrophysicsOfGalaxies #binaryStars #ComputationalAstrophysics #CosmologyAndNonGalacticAstrophysics #DiamondOpenAccess #DiamondOpenAccessPublishing #EarthAndPlanetaryAstrophysics #EpochOfReionization #galaxyFormation #GalaxyMorphology #galaxyProfiles #InstrumentationAndMethodsForAstrophysics #IntergalacticMedium #Ionization #LAEs #lightCurves #LSST #LymanAlphaEmitters #OpenAccess #OpenAccessPublishing #Orbits #SérsicProfile #SolarAndStellarAstrophysics #statmorphLsst #stellarHalos #strongGravitationalLensing #THESAN #zELDA
JWST Glimpses the Cosmic Dawn of the Universe

Thanks to the JWST, galaxies that existed during the Cosmic Dawn have been observed for the first time!

Universe Today
MIRI instrument on JWST detects H-alpha emission during the Epoch of Reionization for the first time

An international team of astronomers led by Pierluigi Rinaldi of the University of Groningen has detected for the first time H-alpha emission in individual galaxies during the so-called Epoch of Reionization, or cosmic dawn. To do so, they used the deepest images taken so far by the MIRI instrument on the James Webb Space Telescope. The result has been accepted for publication in The Astrophysical Journal, and is currently published on the arXiv preprint server.

Phys.org

Some nice work by colleagues at MPIA showing that a pupported z~7.4 quasar is, it seems, just an asteroid.
https://iopscience.iop.org/article/10.3847/2515-5172/accb5b

#Astrodon #Astronomy #Astrophysics #EpochOfReionization #EoRQSO

Construction Begins on the Square Kilometer Array

At twin ground-breaking ceremonies today in South Africa and Australia, project leaders formally marked the start of construction on what will be the largest radio telescope ever built. Dubbed the Square Kilometer Array Observatory (SKAO) – referring to the total area the antennas and dishes will cover when complete – the telescope is not a … Continue reading "Construction Begins on the Square Kilometer Array"

Universe Today