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Posts by Matthieu Le Lain

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Water Vapor Around a Sizzling Supergiant: High-Resolution Spectroscopy of B[e] Supergiant LHA 115-S 18 Researchers have detected water vapor around a B[e] supergiant star for the first time, indicating a likely binary companion for LHA 115-S 18.

Researchers have detected water vapor around a B[e] supergiant star for the first time, indicating a likely binary companion for LHA 115-S 18. 🔭🧪 aasnova.org/2026/04/17/w...

5 days ago 23 11 1 0
Around the Zoo- Radio Galaxy Zoo
Around the Zoo- Radio Galaxy Zoo YouTube video by The Zooniverse

Radio Galaxy Zoo asks volunteers to help identify objects imaged using radio waves. This video is part of Around The Zoo interview series, which you can find at www.youtube.com/playlist?lis...

5 days ago 5 1 0 0
Left and right panels show the same figure layout for 2MASS J15582981-2310077 and 2MASS J16053215-1933159, respectively. The top panels show the high-resolution APOGEE spectra (black filled circles) and the best-fit synthetic spectra (in blue). Syntheses with C/O = 1 are also shown, as well as the residuals between syntheses and observed spectra. The bottom panels show the JWST/MIRI spectra together with the synthetic photospheric spectrum, while the lower inset highlights molecular features detected in the MIRI spectra.

Left and right panels show the same figure layout for 2MASS J15582981-2310077 and 2MASS J16053215-1933159, respectively. The top panels show the high-resolution APOGEE spectra (black filled circles) and the best-fit synthetic spectra (in blue). Syntheses with C/O = 1 are also shown, as well as the residuals between syntheses and observed spectra. The bottom panels show the JWST/MIRI spectra together with the synthetic photospheric spectrum, while the lower inset highlights molecular features detected in the MIRI spectra.

Nicole’s second paper shows young stars and their inner disks don’t share the same chemistry; JWST finds carbon-rich gas in the disk while stars are solar-like. This mismatch suggests disk processes, not stellar composition, set the building blocks of planets. arxiv.org/abs/2604.05221 ☄️🔭

1 week ago 5 1 0 0
Light curves and periodograms of Gaia DR2 3451117071149973120 (TIC ID  312474753) observed in Sectors 43 (top panel) and 45 (bottom panel) are shown. In both sectors, the algorithm identifies a peak near 4.01 cycles d$^{-1

Light curves and periodograms of Gaia DR2 3451117071149973120 (TIC ID 312474753) observed in Sectors 43 (top panel) and 45 (bottom panel) are shown. In both sectors, the algorithm identifies a peak near 4.01 cycles d$^{-1

Top panel shows the TESS light curve of ZTF19abagxei (TIC ID  122519668) observed in Sector 75. Bottom panel presents the corresponding Lomb–Scargle periodogram, where the peaks at 10.94 and $ $13 cycles d$^{-1

Top panel shows the TESS light curve of ZTF19abagxei (TIC ID 122519668) observed in Sector 75. Bottom panel presents the corresponding Lomb–Scargle periodogram, where the peaks at 10.94 and $ $13 cycles d$^{-1

Light curves and periodograms of V2491 Cyg (TIC ID  1868684285) from Sector 81 (top panels) and Sector 74 (bottom panels). In Sector~81, the algorithm identified a peak at approximately 1.35~cycles\,day$^{-1

Light curves and periodograms of V2491 Cyg (TIC ID 1868684285) from Sector 81 (top panels) and Sector 74 (bottom panels). In Sector~81, the algorithm identified a peak at approximately 1.35~cycles\,day$^{-1

{TESS

{TESS

A Catalogue of Orbital Periods of Cataclysmic Variables and Candidates from TESS Observations. Meryem K. Dağ et. al. https://arxiv.org/abs/2603.03539

1 month ago 1 1 0 0
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Euclid: A blue galaxy population and a brightest cluster galaxy in the making in a $z\sim1.74$ MaDCoWS2 galaxy cluster candidate. A. Trudeau (1 and 2) et. al. https://arxiv.org/abs/2603.04960

1 month ago 1 1 0 0
Finder chart for SN 2023axu in the galaxy NGC~2283. The local reference stars listed in Table  {tab:finder

Finder chart for SN 2023axu in the galaxy NGC~2283. The local reference stars listed in Table {tab:finder

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SN 2023axu: A Type IIP Supernova Interacted with a Low-Density Stellar Wind. Zeyi Wang et. al. https://arxiv.org/abs/2603.11646

1 month ago 1 1 0 0
Hypnotic photo of a curtain aurora that truly looks like a flying dragon.The image is extraordinary: an enormous serpentine green shape twisting through the night sky above a snow-covered landscape, with tiny human silhouettes that emphasize the epic scale. It looks like something straight out of a fantasy story, yet it is completely real.

Hypnotic photo of a curtain aurora that truly looks like a flying dragon.The image is extraordinary: an enormous serpentine green shape twisting through the night sky above a snow-covered landscape, with tiny human silhouettes that emphasize the epic scale. It looks like something straight out of a fantasy story, yet it is completely real.

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'Dragon Aurora over Norway' is an enchanting pic showing an impressive auroral curtain, captured by Marco Bastoni above Tromsø in Northern Norway.

The aurora's glittering green glow somehow reminds of a large dragon. 🔭

➡️ apod.nasa.gov/apod/ap18041...

🧪 ⚛️ #sciart #astrophotography #science

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2 months ago 1143 204 11 10
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Why do we do astrophysics? At time of writing, large language models (LLMs) are beginning to obtain the ability to design, execute, write up, and referee scientific projects on the data-science side of astrophysics. What implic...

"Every person is a human being, whose personal development is more important than our short-term scientific accomplishments" - and more bangers in this from David Hogg (spoiler: it's about AI!) arxiv.org/abs/2602.10181 🔭

2 months ago 61 17 2 4

This thread of mine from June 2025 is about MoM-z14, the most distant galaxy spectroscopically confirmed to date, discovered by #JWST 🔭

Well: months later, NASA has just released the official press release (Jan 28, 2026)➡️ science.nasa.gov/missions/web...

And the arXiv paper ...

🧪 #cosmology 1/2

2 months ago 45 16 1 1
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Très fier d’avoir reçu le Grand Prix de l’innovation SAF ! 🏆 Nous avons été récompensés par la Société astronomique de France et son président, Roland Lehoucq pour le projet #SUNSCAN by #STAROS. Une réussite collective avec V. Desnoux, C. Buil, O. Garde et Matthieu Le Lain (@matlastro.bsky.social)

4 months ago 14 4 7 0
Pure black cosmos dotted with hundreds of tiny white, gold, pink, and blue specks—distant galaxies. Top-left: target galaxy GS-NDG-9422 inside a crisp white square box, just a faint, barely-there reddish smudge, almost invisible. A larger inset with white frame near the center zooms it in, turning that pale glow soft orange.That tiny boxed reddish puff on the left feels incredibly old and delicate—a whisper from the universe at one billion years young.

Pure black cosmos dotted with hundreds of tiny white, gold, pink, and blue specks—distant galaxies. Top-left: target galaxy GS-NDG-9422 inside a crisp white square box, just a faint, barely-there reddish smudge, almost invisible. A larger inset with white frame near the center zooms it in, turning that pale glow soft orange.That tiny boxed reddish puff on the left feels incredibly old and delicate—a whisper from the universe at one billion years young.

Exceptional!

The faint blur you see in this NIRCam image refers to GS-NDG-9422, a "strange" galaxy identified with the JWST and announced in 2024.

➡️ science.nasa.gov/missions/web...

Credits: NASA, ESA, CSA, STScI, Alex Cameron (Oxford)

🔭 🧪 #science #extragalactic #cosmology #JWST #Webb

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4 months ago 100 17 2 0
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Orbital parameters of the bright binary alpha Draconis based on amateur spectra from the STAROS database. G. Bertrand et. al. https://arxiv.org/abs/2511.17206

4 months ago 3 2 1 0

Gaia will find ~120,000 exoplanets, mostly super-Jupiters!

From 2014–2025 at L2, it tracked >1B stars so precisely: a pinhead on the Moon from Earth!

Full data by 2030; first release predicts 7,500 planets.

Also: hypervelocity stars, quad systems & ancient galaxy merger remnants. 🔭 🧪 #science

5 months ago 31 6 3 2
My linocut of Annie Jump Cannon shows her in a 3/4 profile view wearing a shirt with a lace collar and her hair up. She is printed in a gradient of violet at the bottom to green at the top, printed on white 11” x 14” paper. The background is printed in a gradient (left to right) of dark blue, light blue, yellow, pale yellow, pale orange, orange and red. The background block excludes her silhouette of shoulder and head with the exception of a smattering of small dots in a swath from upper left to lower right (which extends to white spots on the coloured background). Also along the bottom are a series of circles of decreasing size (left to right, blue through red) labelled O, B, A, F, G, K, M. There’s a axis line along the bottom with 6 tick marks. Vertically from top to bottom along the left side are 15-, 10-, 5-, 0, 5, 20, 15.

My linocut of Annie Jump Cannon shows her in a 3/4 profile view wearing a shirt with a lace collar and her hair up. She is printed in a gradient of violet at the bottom to green at the top, printed on white 11” x 14” paper. The background is printed in a gradient (left to right) of dark blue, light blue, yellow, pale yellow, pale orange, orange and red. The background block excludes her silhouette of shoulder and head with the exception of a smattering of small dots in a swath from upper left to lower right (which extends to white spots on the coloured background). Also along the bottom are a series of circles of decreasing size (left to right, blue through red) labelled O, B, A, F, G, K, M. There’s a axis line along the bottom with 6 tick marks. Vertically from top to bottom along the left side are 15-, 10-, 5-, 0, 5, 20, 15.

For Day 21 of #spacetober_challenge prompt star: trailblazing US #astronomer Annie Jump Cannon (1863 – 1941), here with her stellar classification system which sorted stars based on spectral types, revealing their temperature from hot blue to cool red stars: O,B,A, F, G, K & M. 🧪🐡👩🏼‍🔬🔭#histsci 🧵

6 months ago 101 32 1 2
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Commander | Siril - Le livre de référence

Bonne nouvelle pour les francophones, le livre sur Siril est disponible à la précommande, avec une réduction valable tout le mois de septembre !!
siril.fr/commander/

7 months ago 7 5 1 0
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Astronomers Map Stellar ‘Polka Dots’ Using NASA’s TESS, Kepler - NASA Science Scientists have devised a new method for mapping the spottiness of distant stars by using observations from NASA missions of orbiting planets crossing their

Sweet NASA feature article on @sabinastro.bsky.social's work on mapping stellar surfaces: 🔭🧪 #stellarastro

science.nasa.gov/missions/tes...

Why? Because:
1) #StarsAreStillInteresting
2) Messy stars complicate our view of exoplanet atmospheres. To remove stellar contamination, you must map it. 🗺️

7 months ago 40 13 2 0

Betelgeuse is a double! Fun to learn something new about a familiar star.

9 months ago 148 28 7 6
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Measuring the Suns radial velocity variability due to supergranulation over a magnetic cycle In recent years supergranulation has emerged as one of the biggest challenges for the detection of Earth-twins in radial velocity planet searches. We used eight years of Sun-as-a-star radial velocity ...

It’s paper day 🎉!! If you are interested in seeing how supergranulation changes over a solar cycle in RVs give it a read! arxiv.org/abs/2506.23693

9 months ago 29 9 2 2
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Spectroastrometry and Reverberation Mapping of Active Galactic Nuclei. II. Measuring Geometric Distances and Black Hole Masses of Four Nearby Quasars. Yan-Rong Li et. al. https://arxiv.org/abs/2502.18856

9 months ago 1 1 0 0
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Cosmic Indigestion Is Causing Black Holes to Spit Up Stars After black holes devour stars, sometimes the feast comes back up

MY FIRST EVER ARTICLE FOR SCIENTIFIC AMERICAN IS OUT!!!

It's all about how black holes shred stars and how we discovered that black holes "burp" after eating them, and even includes a black hole called Jetty McJetface! What's not to love? 🤩

www.scientificamerican.com/article/why-...

🔭🧪🎢

10 months ago 591 122 48 12
A photo of the slide with the December 2026 release date

A photo of the slide with the December 2026 release date

Finding out about Gaia at #EAS2025Cork! ☄️

Just announced: Gaia DR4 will be released in December 2026!

9 months ago 95 37 1 1
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Here's a cool spectro and photometry experiment to measure the mass of supermassive black holes from your backyard :) Based on single-epoch estimators in broad-line AGN. 🌈🔭 #astrophysics #astronomy #spectroscopy #photometry

guillaumebertrand.notion.site/Estimating-b...

9 months ago 9 3 0 0
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Happy to announce that the line-detector.oca.eu website is now online!
It allows the user to select the stellar type, [M/H], λ- range, and resolving power and the page returns:
-purity of the line and minimum S/N required to detect it.
-interactive plot to identify the lines in the spectra

10 months ago 11 6 0 1
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We found the most distant confirmed galaxy
(some Sergej Boebka vibes 😅)

arxiv.org/abs/2505.11263

11 months ago 48 15 0 6
This cluster of stars is known as Messier 15, and is located some 35,000 light-years away in the constellation of Pegasus (The Winged Horse). It is one of the oldest globular clusters known, with an age of around 12 billion years. This new image is made up of observations from Hubble's Wide Field Camera 3 and Advanced Camera for Surveys in the ultraviolet, infrared, and optical parts of the spectrum. (NASA, ESA)

This cluster of stars is known as Messier 15, and is located some 35,000 light-years away in the constellation of Pegasus (The Winged Horse). It is one of the oldest globular clusters known, with an age of around 12 billion years. This new image is made up of observations from Hubble's Wide Field Camera 3 and Advanced Camera for Surveys in the ultraviolet, infrared, and optical parts of the spectrum. (NASA, ESA)

Figure 1. Comparing two theoretical isochrones we constructed with different ages, MC parameters, distance, and reddening. The observational data for M15 is plotted in the background, with photometric uncertainty estimated from the AS test plotted on the right.

Figure 1. Comparing two theoretical isochrones we constructed with different ages, MC parameters, distance, and reddening. The observational data for M15 is plotted in the background, with photometric uncertainty estimated from the AS test plotted on the right.

This is the globular cluster M15, imaged by Hubble. It's a great target for binoculars or backyard telescopes, in the constellation Pegasus.

Jiaqi Ying et al. measured M15's age with 3% precision. This group of stars formed *immediately* after the Universe did.

arxiv.org/abs/2505.02969

🔭🧪 #stars

11 months ago 232 35 4 4
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Zooniverse The Zooniverse is the world’s largest and most popular platform for people-powered research.

Been an exciting week for @galaxyzoo.org - our relaunch with JWST imaging has resulted in highest daily classification rate since March 2020. www.galaxyzoo.org. 🔭👩‍🔬🎉

11 months ago 22 11 0 1
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Stellar Physics Across the HR Diagram with Gaia Gaia Data Release 3 (GDR3) contains a wealth of information to advance our knowledge of stellar physics. In these lecture notes we introduce the data products from GDR3 that can be exploited by the st...

Interested in stellar physics? Orlagh L. Creevey has posted their lecture notes & recorded lecture from a day-long introduction to stellar physics with Gaia!

#astroedu #stellarastro 🔭 🧪

11 months ago 84 21 1 1
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The new official paper/poster browser for ICLR 2025 is out.
Enjoy!

iclr2025.vizhub.ai

#iclr #ai #iclr2025

1 year ago 21 5 1 0
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📢 New dataset out!

We introduce HypoGen💥, a dataset of ~5.5K structured problem–hypothesis pairs (Bit–Flip–Spark + Chain‑of‑Reasoning) to advance LLM-driven scientific ideation💡.

Fine‑tuned LLaMA 3.1 8B & R1‑distilled models show significant gains. Humans are still the best🥇.

1 year ago 5 4 1 1
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Excited to announce our new paper as part of our 2^2 week: AstroLLaVA, a vision language model for astronomy that enables natural dialogue with astronomical imagery! Shout out to Sharaf Zaman for leading this work arxiv.org/abs/2504.08583 🔭☄️

1 year ago 7 3 1 2