@astrohazra
Astrophysicist, Assistant Professor @IITKanpur Previously @University of Vienna, Leiden Observatory and Trinity College Dublin Working on atmospheric escape, exoplanetary magnetic field, star-planet interaction & Sun Web: https://gopalhazra.github.io/
All the best! In case you this helps, I share some of my assignments from computational physics course that I taught last year :)
github.com/gopalhazra/C...
Announcing the 8th Other Worlds Laboratory (OWL) Exoplanet Summer Program, Aug 10-27, 2026. We wish to foster new and existing research collaborations by outstanding visitors, with stays of 1 to 3 weeks at the beautiful UC Santa Cruz campus. Applications accepted Feb 5-March 5.
owl.ucsc.edu/summer/
Our work assimilates 30 years of daily magnetograms in a 3D dynamo model for the first time to construct interior magnetic field of the Sun. Recently published in ApJL βΊοΈ
Many congratulations!
Cartoon of a happy scientist giving a thumbs up. Text reads: Happy New Year from the arXiv team.
Happy arxiv:2601 to all who celebrate! πππ¬
We are so thankful for everyone who uses arXiv everyday to share and discover new research.
Happy new year to all - here's hoping for a 2026 full of #openaccess science & lots of new discoveries.
Thank you so much Satabdwa βΊοΈ
In this work, we assimilated 10000 daily magnetograms (1996β2025) into a 3D solar dynamo model & reconstructed both the amplitude and evolution of the interior magnetic field. To the best of our knowledge, this is the first observationally guided reconstruction of the Sunβs internal magnetic field.
The year 2025 is ending with good news βΊοΈ ! First paper of my PhD student Soumyadeep got accepted in the prestigious Astrophysical Journal Letters (IF=11.7), where we reconstructed magnetic field inside the Sun using data assimilation from observations.
Link to the paper: arxiv.org/abs/2509.23959
π
For international participants :)
Is there any provision for joining online?
This would be us!!! Have you ever thought if the sunspots that we consider have morphological asymmetry and not spherical in nature, then how the polar field will change? We answer the question here :)
First time we have assimilated three decades of solar observations into a dynamo model to probe solar interior! Happy reading βΊοΈ
The cost in APC for publishing a paper in MNRAS is now Β£2356. Converting that to dollars at current rates gives about $3150 per paper.
On that basis, @ojastro.bsky.social having now published 357 articles has saved the global astrophysics community about $1.1M (for an outlay of around $10K).
Just put the assignments and solutions of the computational physics course that I taught at IIT Kanpur:
github.com/gopalhazra/C...
Please feel free to download and play around
Happy coding :D
APPLICATIONS DUE IN ONE WEEK!
Abstracts close this Friday for the Fall 2025 STScI Science Workshop on Atmospheric Escape and Replenishment. We'd love to see you in Baltimore in November!
Check it out and let me know if you've any questions. π #exoplanets
www.stsci.edu/contents/eve...
Figure 7. Time series of S-indices for five targets with a range of spectral types. The top three panels show data from 1965 to 2024 for HD 78366 (F dwarf), HD 81809 (G dwarf), and the K-dwarf HD 26965, including historic MWO data (timespan in yellow) and newly obtained OWLS measurements (timespan in blue). We plot a curve on the G and K stars with three Lomb-Scargle (sinusoidal) terms, with periods ranging from 8 to 15 years. The OWLS S-indices from 2020-2024 for two M dwarfs GJ 388 B and GJ 494 are shown in the bottom row.
Presenting: the Olin Wilson Legacy Survey (OWLS). π§ͺπ #stellarastro
Since 2019, Leslie Hebb, Suzanne Hawley and I have been monitoring spectra of bright northern stars including those monitored by Olin Wilson from ~1965-2000, and planet-hosting stars
And we're not done.
arxiv.org/abs/2507.07330
Figure 1
Figure 2
Top panel: {
![Cross-correlation signature of the ultra hot-Jupiter WASP-121b as a function of orbital phase and radial-velocity (RV) shift, collected from 8 ESPRESSO observing nights [0.38--0.78 Β΅m,][]{PelletierEtal2025ajWASP121bCRIRESplus](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:32r7scd5hucgv552zjfuaigc/bafkreie2or2bojfcdhijikfssy5hgdi6vzz2qbe765djvtvykynqqbayei@jpeg)
Cross-correlation signature of the ultra hot-Jupiter WASP-121b as a function of orbital phase and radial-velocity (RV) shift, collected from 8 ESPRESSO observing nights [0.38--0.78 Β΅m,][]{PelletierEtal2025ajWASP121bCRIRESplus
High-resolution Ultraviolet-to-nearinfrared Characterization of Exoplanet Atmospheres. Patricio E. Cubillos et. al. https://arxiv.org/abs/2507.03060
At Exomol conference!
It was an excellent event! So much fun, woohoo!
πIf you work in stats you've probably heard of nested sampling: MCMCs fancy cousin. Enough people have asked me how it works that I've written an article (including examples!) explaining:
1. What NS is
2. Why we need it over MCMC
3. How to know if it's working
hughmcdougall.github.io/blog/03_stat...
My review article on "Atmospheric Escape from Exoplanets" is finally published in Reviews of Modern Plasma Physics. The full-text copy of the article is available in the following link:
rdcu.be/ek5aY
Flare from February 22nd 2024, as seen through the 8 filters of Aditya-L1's instrument SUIT
Last year, #ISRO 's solar probe #Adiyta-L1 witnessed a X6.3 #flare and captured 1st images from the #chromosphere. Published today by scientists led by #IUCAA and including #MPSGoettingen in #TheAstrophysicalJournalLetters. More here: www.mps.mpg.de/8324638/news... βοΈπ
image credit: SUIT/Aditya-L1
I am excited to share that my review paper is in arXiv today. This paper gives the basics and overall progress of the field-atmospheric escape from exoplanets, in recent years. It will appear soon in the Reviews of Modern Plasma Physics.
arxiv.org/abs/2502.18124
We are delighted to announce an exoplanet workshop at IIT Kanpur from 4-6th April 2025. Please share the word.
Deadline: 27th Feb 2025
For application: sites.google.com/view/exows25...
Publication alert!
Our paper on the effect of Coronal Mass Ejections on planetary atmospheric loss and habitability is finally published in MNRAS @rasjournals.bsky.social
academic.oup.com/mnras/articl...
Summer internship opportunities at IIT Kanpur for masters and UG students to work in a research group. Check the following link
Masters students: www.iitk.ac.in/cce/SARIP/
UG students: surge.iitk.ac.in/dates.php
