📄 First Results from the Catalina Real-Time Transient Survey
Quicklook:
Drake, A. J. et al. (2009) · The Astrophysical Journal
Reads: 139 · Citations: 1351
DOI: 10.1088/0004-637X/696/1/870
🔗 https://ui.adsabs.harvard.edu/abs/2009ApJ...696..870D/abstract
#Astronomy #Astrophysics #Galaxies #Supernovae #BlLacertaeObjectsGeneral
We report on the results from the first six months of the Catalina Real-Time Transient Survey (CRTS). In order to search for optical transients (OTs) with timescales of minutes to years, the CRTS analyses data from the Catalina Sky Survey which repeatedly covers 26,000 of square degrees on the sky. The CRTS provides a public stream of transients that are bright enough to be followed up using small telescopes. Since the beginning of the survey, all CRTS transients have been made available to astronomers around the world in real time using HTML tables,RSS feeds, and VOEvents. As part of our public outreach program, the detections are now also available in Keyhole Markup Language through Google Sky. The initial discoveries include over 350 unique OTs rising more than 2 mag from past measurements. Sixty two of these are classified as supernovae (SNe), based on light curves, prior deep imaging and spectroscopic data. Seventy seven are due to cataclysmic variables (CVs; only 13 previously known), while an additional 100 transients were too infrequently sampled to distinguish between faint CVs and SNe. The remaining OTs include active galactic nucleus, blazars, high-proper-motions stars, highly variable stars (such as UV Ceti stars), and transients of an unknown nature. Our results suggest that there is a large population of SNe missed by many current SN surveys because of selection biases. These objects appear to be associated with faint host galaxies. We also discuss the unexpected discovery of white dwarf binary systems through dramatic eclipses.
Weekly Update from the Open Journal of Astrophysics – 04/04/2026
It may be the Easter weekend, but it’s still time for a Saturday morning 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 71 and the total so far published by OJAp up to 519. This update coimpletes the first quarter of 2026, which suggests that if we continue to publish at the same rate we’ll reach about 280 for the year.
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 “Testing halo models for constraining astrophysical feedback with multi-probe modeling: I. 3D Power spectra and mass fractions” by Pranjal R. S. (U. Arizona, USA), Shivam Pandey Johns Hopkins U., USA), Dhayaa Anbajagane (U. Chicago, USA), Elisabeth Krause (U. Arizona) and Klaus Dolag (Max Planck Institute for Astrophysics, Germany). This paper was published on Tuesday March 31st 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:
https://fediscience.org/@OJ_Astro/116322295318460212
The second paper for this week, also published on Tuesday March 31st in the folder Cosmology and Nongalactic Astrophysics, is “Validation of the DESI-DR1 3×2-pt analysis: scale cut and shear ratio tests” by Ni Putu Audita Placida Emas (Swinburne University of Technology, Australia) and an international cast of 56 others. This study validates the combined analysis of galaxy clustering and weak gravitational lensing data from various surveys, ensuring accurate tests of the standard cosmological model using future Stage-IV 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/116322348900996677
Next one up, the third paper of the week, also published on Tuesday March 31st in the folder Cosmology and Nongalactic Astrophysics, is “Differentiable Stochastic Halo Occupation Distribution with Galaxy Intrinsic Alignments” by Sneh Pandya and Jonathan Blazek (both of Northeastern University, USA). This is a paper introducing diffHOD-IA, a differentiable model for galaxy population analysis that incorporates intrinsic alignments and halo occupation distribution. It’s validated against existing models and can be used in next-generation weak-lensing analyses.
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/116322403314492269
The fourth and final paper this week, published on Wednesday April 1st (but not a joke), is “The Growth of Dust in Galaxies in the First Billion Years with Applications to Blue Monsters” by Desika Narayanan (U. Florida, USA) and 11 others based in the USA and Europe. This one is in the folder Astrophysics of Galaxies; it presents a simulation-based study of dust accumulation in early galaxies via supernovae production and rapid growth on tiny dust grains, with local density and grain size being important factors.
The overlay is here:
The finally accepted version of this paper can be found here and the Mastodon announcement is here:
https://fediscience.org/@OJ_Astro/116328145696781139
And that concludes the update for this week. I’ll do another next week, but I’m expecting a fairly low number of papers owing to the Easter vacation.
#3x2ptAnalysis #arXiv250713317v2 #arXiv250918266v2 #arXiv251005539v2 #arXiv260204977v2 #AstrophysicsOfGalaxies #CosmologyAndNonGalacticAstrophysics #DESI #DiamondOpenAccess #DiamondOpenAccessPublishing #diffHODIA #dust #dustGrains #galaxyFormation #haloModels #InstrumentationAndMethodsForAstrophysics #intrinsicAlignments #MilkyWay #OpenAccess #OpenAccessPublishing #supernovae #weakGravitationalLensing
Weekly Update from the Open Journal of Astrophysics – 28/03/2026
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:
https://fediscience.org/@OJ_Astro/116282898593823676
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:
https://fediscience.org/@OJ_Astro/116282956216523629
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:
https://fediscience.org/@OJ_Astro/116283020198162509
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:
https://fediscience.org/@OJ_Astro/116288916505020843
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:
https://fediscience.org/@OJ_Astro/116288982927449308
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:
https://fediscience.org/@OJ_Astro/116294271036561714
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:
https://fediscience.org/@OJ_Astro/116294325612775166
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:
https://fediscience.org/@OJ_Astro/116300257535421390
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!
#arXiv250908737v2 #arXiv251009604v2 #arXiv251017721v2 #arXiv251106755v4 #arXiv251113650v3 #arXiv251118901v2 #arXiv251223138v2 #arXiv260322392v1 #AstrophysicsOfGalaxies #BayesianMethods #BrownDwarfs #CosmologyAndNonGalacticAstrophysics #DiamondOpenAccess #DiamondOpenAccessPublishing #EarthAndPlanetaryAstrophysics #GAIA #galaxyFormation #InstrumentationAndMethodsForAstrophysics #JWST #lightCurves #LocalBubble #MassiveBlackHoleSeeds #metallicity #MilkyWay #OpenAccess #OpenAccessPublishing #Pantheon #radioGalaxy #supernassiveBlackHoles #supernovae #TransientAstronomy #XRayAstronomy
NASA X-Ray Mission Gets Fresh Look at 2,000-Year-Old Supernova
La rara supernova di tipo Icn SN 2024abvb è tra le più luminose conosciute
Un team internazionale di astronomi ha effettuato osservazioni fotometriche e spettroscopiche di SN 2024abvb, una supernova recentemente scoperta appartenente al raro tipo Icn. La nuova campagna osservativa fornisce informazioni importanti sulle proprietà e sulla natura di questa supernova.
https://umbertogaetani.substack.com/p/la-rara-supernova-di-tipo-icn-sn
Cosa succede all'interno di una stella massiccia prima che esploda come una supernova?
#astrofisica @astronomia
#supernovae
I ricercatori hanno ricostruito gran parte dei complessi dettagli che stanno dietro alle supernovae di tipo II. Tuttavia gli astrofisici hanno ancora alcune domande aperte. Una di queste riguarda gli inviluppi estesi delle stelle progenitrici e le loro curve di luce.
https://umbertogaetani.substack.com/p/cosa-succede-allinterno-di-una-stella
German Virtual Observatory
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Umberto gaetani