Julien Girard
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Julien Girard
@juliengirard.space
420 followers 380 following 99 posts
astronomer, scientist and coronagraphist at STScI, exoplanet portraitist, extreme turophile, father, grumpy urban farmer hobbyist
he/him
views EN FR ES my own
https://linktr.ee/juliengirard
🦋 🐘 @djulik on 🦤
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Julien Girard @juliengirard.space · Nov 22
Trying to understand and use 🦋 more, I created this "starter pack" to gather colleagues working in high contrast imaging (all flavors). Feel free to share stuff and invite more people.

go.bsky.app/AasjG9B
juliengirard.space
Debris disk around TWA 20, a M star, imaged with JWST/NIRCam coronagraph at 2µm!
Palatnick et al. 2025
arxiv.org/abs/2510.20216
umbertogaetani.mastodon.uno.ap.brid.gy Umberto gaetani @umbertogaetani.mastodon.uno.ap.brid.gy · Nov 6
Le osservazioni del JWST scoprono un grande disco di detriti attorno a una vicina stella nana M

#Webb @astronomia

Un team internazionale di astronomi ha utilizzato il James Webb Space Telescope (JWST) per osservare una stella nana rossa vicina, nota come TWA […]

[Original post on mastodon.uno]
Immagine deconvoluta del disco di detriti di TWA 20 nel filtro F200W, ottenuta eseguendo una routine di deconvoluzione sul risultato MCRDI. L’immagine è ruotata con il Nord verso l’alto.
December 9, 2025 at 9:03 PM
juliengirard.space
The CHesapeake bay area EXOplanet Meeting #CHEXO12 has started @jhuapl.bsky.social with a nice and big crowd despite the snow!

www.chexo.org #exoplanets
December 5, 2025 at 3:13 PM
juliengirard.space
Good news! En hora buena!

I know this is probably not the time yet but choosing Tenerife (or even Madrid or Barcelona) for Spanish HQ would be wise, more attractive for scientists, engineers, staff and their families :)

No offense for Santa Cruz de La Palma, looks beautiful!!
barrientes.bsky.social Jackie Barrientes @barrientes.bsky.social · Nov 12
TMT International Observatory LLC will jointly develop with the Ministry of Science, Innovation and Universities a detailed roadmap toward the potential realization of the TMT at the Observatorio del Roque de los Muchachos (La Palma, Spain).
TMT Explores a Promising Path Forward in Spain
TMT is exploring a promising avenue for a new observatory based in Spain.
www.tmt.org
November 12, 2025 at 3:54 PM
Reposted by Julien Girard
kevinhainline.bsky.social
this is from a paper I'm putting together of a 300 K brown dwarf and it's kind of insane how similar it is
a chart showing the flux from a Y dwarf as a function of wavelength, with a picture of the little brown dwarf in the top right (it looks like a rose), and the 1D and 2D spectra underneath. It rises only at longer wavelengths. It looks a lot like this chocolate price chart.
November 11, 2025 at 12:59 AM
juliengirard.space
Jupiter aurora movie by JWST NIRCam!
www.youtube.com/watch?v=b1Fo...
November 5, 2025 at 7:48 PM
Reposted by Julien Girard
mpe-garching.bsky.social
🤩The @4most-eu.bsky.social (#4MOST) facility on @eso.org VISTA telescope in Chile achieved first light.
#MPE scientists played a leading role in developing the Operations System, enabling to link #eROSITA’s X-ray universe with large-scale structure of galaxies.
➡️ More: www.mpe.mpg.de/8102833/news...
4MOST Begins its Journey of Cosmic Discovery
4MOST embarks on a cosmic journey, capturing spectra of thousands of celestial objects simultaneously, unlocking secrets of the universe.
www.mpe.mpg.de
October 21, 2025 at 12:01 PM
Reposted by Julien Girard
4most-eu.bsky.social
First Light for 4MOST!

The 4-metre Multi-Object Spectroscopic Telescope (4MOST) has captured its very first spectra!

Video Credit: AIP/R. de Jong, AIP/K. Riebe, AIP/A. Saviauk, CRAL/J.-K. Krogager
First Light for 4MOST!
YouTube video by 4-meter Multi-Object Spectroscopic Telescope
youtu.be
October 21, 2025 at 12:00 PM
juliengirard.space
Love the 2b_or_not_2b repo!!
mattkenworthy.bsky.social Matthew Kenworthy @mattkenworthy.bsky.social · Sep 12
Some sad #exoplanets news in a paper led by me: “YSES 2b is a background star”. A distant M dwarf star some 2 kiloparsecs behind the star just so happens to have a non-zero proper motion in EXACTLY the wrong direction: this required multiple GRAVITY observations to solve… #astrosci #astrodon
A coiled spiral representing proper motion plus parallax shows a fit to several astrometric points, showing that the object next to the star YSES 2 is probably a very distant M dwarf star far away in our Galaxy. Drat, damn and blast!
September 14, 2025 at 4:10 AM
Reposted by Julien Girard
mattkenworthy.bsky.social
Two papers announcing the discovery of a directly imaged 6 Jupiter mass planet around binary system HD 143811 AB Squicciarini+ and Jones+ in Sco-Cen - Keck, Gemini and VLT all imaging this companion and confirmed with several years of common proper motion. #astrodon #exoplanet #exosci
Figure from Squicciarini et al. showing three panels with a white dot on a black and blue stippled background, indicating the location of the planet in GPI and SPHERE IRDIS data.&10; Three panel image from Jones et al. showing a white dot on a stippled background. The planet is in the 11 o'clock position in all three images.
September 9, 2025 at 9:29 AM
Reposted by Julien Girard
megschwamb.bsky.social
JWST successfully observed interstellar object (ISO) 3I/ATLAS. Interesting results. The composition of the coma could be due to a few different scenarios. Additional JWST observations of the object closer to the sun are needed. science.nasa.gov/blogs/3iatla...
NASA’s Webb Space Telescope Observes Interstellar Comet - NASA Science
NASA’s James Webb Space Telescope observed interstellar comet 3I/ATLAS Aug. 6, with its Near-Infrared Spectrograph instrument. The research team has been
science.nasa.gov
August 25, 2025 at 10:28 PM
juliengirard.space
Amazing!!!! A NEW gap-carving planet! So far, we haven't been able to image many. WISPIT 2b, like PDS 70 b&c is imaged at many wavelengths from 656nm (H⍺, blue here) to 3.7µm (👏MagAO-X @xwcl.science.web.brid.gy). VLT/SPHERE polarized scattered light at 1.6µm+reddish planet at 2.2µm in the gap, wow!
mattkenworthy.bsky.social Matthew Kenworthy @mattkenworthy.bsky.social · Aug 26
Proud supervisor moment: #LeidenObservatory graduate student Richelle van Capelleveen led one of two papers on our discovery of WISPIT 2b, a 5 Jupiter mass exoplanet clearing a path in a circumstellar disk. Laird Close and his team saw it in H-alpha, indicating gas accretion #astrodon 🔭 🧪
A series of concentric black and white ovals against a black background, with a dim red dot in the lower left of one of the paths of a black ring. The ovals are dust rings around a young star, and the red dot is a 5 Jupiter mass exoplanet called WISPIT 2b.
August 26, 2025 at 12:11 PM
Reposted by Julien Girard
setiinstitute.bsky.social
Next #SETILive: Closest Exoplanet Yet?
TODAY, 8 August, 3:15 pm PDT

Join astronomers @allplanets.bsky.social and Julien Girard (STScI) as they discuss recent evidence of a Saturn-mass gas giant orbiting Alpha Centauri A—located just 4 light-years away. 🧪 🔭

WATCH LIVE: buff.ly/TplMAD5
SETI Live record button logo. Text: Closest Exoplanet Yet? with Franck Marhis and Julien Girard. Background: Artist's concept of a gas giant planet orbiting at a distance from a bright star. Inset: Photos of Franck Marchis and Julien Girard.
August 8, 2025 at 10:00 PM
juliengirard.space
Wow, Tonight I just completed 8 years @stsci.edu. I love it 😊

I realize I now have worked there in Baltimore as much as I spent @eso.org in Chile. 16 years as scientist, collectively supporting instruments, operations, maximizing the science return at major observatories, ground and space!
August 6, 2025 at 11:29 PM
Reposted by Julien Girard
kellylepo.bsky.social
The Space Telescope Science Institute's MAST archive contains 300 million astronomical observations from over 23 different missions.

Here is an animation showing how the archive has built up over time.

Credit: Julie Imig, STScI
August 1, 2025 at 1:16 AM
juliengirard.space
Experiencing FOMO big time, not attending #HWO2025) I am glad a lot is youtube broadcasted. I am especially eager to watch these panels sessions on ground/based synergies and on how the #RomanCoronagraph will inform the design choices of the HWO coronagraphs www.youtube.com/watch?v=7Vq3...
stsci.edu Space Telescope Science Institute @stsci.edu · Jul 29
STScI Director Dr. Jennifer Lotz (left) moderates a panel on observatory synergies at the Habitable Worlds Observatory conference today in Washington, D.C. #HWO2025 #HWO25 🔭 🧪 ☄️
Three people participating in a panel discussion at a conference, seated at a table with microphones in front of each person.
July 29, 2025 at 9:39 PM
juliengirard.space
Who saw this coming?

Maybe that should go into the discussion of what @eso.org will do after it's ELT, an ELT-N with a TMT design?

I think as a community what we all want is A >25m telescope in the North.
July 23, 2025 at 6:49 PM
juliengirard.space
"This is just a small peek"
In 9 hours, livestream!
vrubinobs.bsky.social NSF–DOE Rubin Observatory @vrubinobs.bsky.social · Jun 23
Introducing...your sneak peek at the cosmos captured by NSF–DOE Vera C. Rubin Observatory!

Can you guess these regions of sky?

This is just a small peek...join us at 11am US EDT for your full First Look at how Rubin will #CaptureTheCosmos! 🔭🧪

#RubinFirstLook
ls.st/rubin-first-look-livestream
A sprawling, textured field of galaxies scattered across the deep black of space. It is filled with the delicate smudges and glowing cores of galaxies of many shapes, sizes and colors, as well as the bright multi-colored points of stars. The image focuses on a collection of interacting galaxies connected by delicate streams of stars. At top center lies a large elliptical galaxy that is dense and smooth, like a polished stone glowing with golden light. Like delicate spider silk or stretched taffy, these stellar bridges link the large elliptical to the few larger galaxies beneath, evidence of past collisions. All throughout the image, thousands of galaxies gather in clusters or are spread throughout, like glittering gems strewn on a table. Some are sharp-edged and spiral, like coiled ribbons; others round and diffuse, like polished pebbles. Still others are just smudges of various colors against the black of space. The background is peppered with pinpoint stars in reds, yellows, and blues, crisp against the velvet black. A cosmic tapestry of glowing tan and pink gas clouds with dark dust lanes. In the upper right, the Trifid Nebula resembles a small flower in space. Its soft, pinkish gas petals are surrounded by blue gas, and streaked with dark, finger-like veins of dust that divide it into three parts. It radiates a gentle, misty glow, diffuse and soft like the warmth of breath on a cold hand. To the lower left, the much larger Lagoon Nebula stretches wide like a churning sea of magenta gas, with bright blue, knotted clumps sprinkled throughout where new stars are born. Both nebulae are embedded in a soft tan backdrop of gas that is brighter on the left than on the right, etched with dark tendrils of dust and sprinkled with the pinpricks of millions of stars. A sprawling, textured field of galaxies scattered across the deep black of space. It is filled with the delicate smudges and glowing cores of galaxies of many shapes, sizes and colors, as well as the bright multi-colored points of stars. To the lower left is a region filled with the hundreds of golden glittering gems of a distant galaxy cluster. In the foreground, below and right of center, two blue spiral galaxies look like eyes beneath the entangled mass of a triple galaxy merger in the upper right. A few bright blue points of foreground stars pierce the glittering tapestry. All throughout the image, thousands of galaxies gather in clusters or are spread throughout, like glittering gems strewn on a table. Some are sharp-edged and spiral, like coiled ribbons; others round and diffuse, like polished pebbles. Still others are just smudges of various colors against the black of space. The background is peppered with pinpoint stars in reds, yellows, and blues, crisp against the velvet black.
June 23, 2025 at 5:20 AM
juliengirard.space
Habemus CSIT for the Habitable Worlds Observatory (HWO)

science.nasa.gov/astrophysics...
Habitable Worlds Observatory News - NASA Science
Building on the foundation of the Habitable Worlds Observatory (HWO) Technology Maturation Project Office (TMPO), NASA is now establishing the HWO Community
science.nasa.gov
June 10, 2025 at 8:25 PM
juliengirard.space
Please watch the @aas.org Press Conference where @balmer.bsky.social presented this thrilling result: THE NEW(even if expected from astrometry)LY IMAGED, COLD (~2ºC), MATURE giant exoplanet 14 Her c with JWST/NIRCam!!!

Congrats Daniella, William and the whole team 😀

www.youtube.com/live/Z7niXAH...
June 10, 2025 at 7:18 PM
Reposted by Julien Girard
mattkenworthy.bsky.social
Dr. Kielan Hoch has a #Nature paper on #JWST observations of the star YSES 1 with its two gas giant planets. She and her team have discovered a circumplanetary disk around the larger 1b and silicate clouds in 1c. Wonderful results and more to come - watch this space! #exoplanet #astrodon
The two gas giant planets YSES 1b has a circumplanetary disk surrounding a purple coloured visualisation of the gas giant, and a sandy coloured gas giant 1c in the lower right. The star can be seen in the distance. The image is by Ell Bogat at UMD.
June 10, 2025 at 5:56 PM
juliengirard.space
Chen Xie, Christine Chen et al., colleagues of our EPSIG group at STScI/JHU just published water ice detections with #HighContrast Near-Infrared (IFU) Spectroscopy with #JWST/NIRSpec!!
stsci.edu Space Telescope Science Institute @stsci.edu · May 14
NEW: Is frozen water around other stars? #NASAWebb provided proof for the first time: It is! Webb identified water ice around HD 181327, a Sun-like star that lies 155 light-years away. The majority is found where it’s coldest—farthest from the star: webbtelescope.pub/42Vopw0 🔭 🧪
An illustration of Sun-like star HD 181327 and its surrounding debris disk. The star is at top right. It is surrounded by a far larger debris disk that forms an incomplete ellpitical path and is cut off at right. There’s a huge cavity between the star and the disk. The debris disk is shown in shades of light gray. Toward the top and left, there are finer, more discrete points in a range of sizes. The disk appears hazier and smokier at the bottom. The star is bright white at center, with a hazy blue region around it. The background of space is black. The label Artist's Concept appears at lower left.
May 14, 2025 at 3:55 PM
juliengirard.space
I could not help it…

(note, the top picture was taken in Jura, France by the weather forecast group a météo franc-comtoise)
March 26, 2025 at 4:44 PM
juliengirard.space
We'll be presenting this Coronagraphy JWebbinar with Aarynn Carter and Jonathan Aguilar, register here before March 30 if you're interested.

#JWST #Coronagraph
www.stsci.edu/jwst/science...
under 2025, it's number 40
jwstobserver.bsky.social JWST Observer @jwstobserver.bsky.social · Mar 12
Registration is now open for the next JWebbinar – NIRCam and MIRI Coronagraphy: An Update 3 Years into #JWST Operations – to be held on April 3rd. Get the details: ow.ly/ewNq50VgoQW
JWebbinar promotional image
March 25, 2025 at 10:50 PM
Reposted by Julien Girard
jwstobserver.bsky.social
A new series of python-based Jupyter notebooks are now available for all four #JWST instruments and 13 observing modes. Read more: ow.ly/bjZ850VnlG8
Line drawing of JWST on a composite background of the Cosmic Cliffs observed by JWST
March 24, 2025 at 1:27 PM
juliengirard.space
So happy & proud of what William Balmer (PhD student @johnshopkinsiaa.bsky.social + in our group at @spacetelescope.bsky.social) has managed to do with the JWST/NIRCam Coronagraphy mode. To achieve this incredible image, we had to push performance to the max,

1/n

science.nasa.gov/missions/web...
March 17, 2025 at 10:35 PM