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Shashank Dholakia

@astroshashank.bsky.social
707 followers 301 following 141 posts

Astrophysics PhD at University of Queensland | UC Berkeley '21 | Exoplanets and Stars | @astrosoundbites.bsky.social co-host | Astrophotographer shashankdholakia.github.io

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Reposted by Shashank Dholakia
Ethan Chappel @chappelastro.com · 29/09/2026
Saturn with Mimas and Dione on August 3rd, 2026. #Astronomy #Astrophotography
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Shashank Dholakia @astroshashank.bsky.social · 26/09/2026
Saturn is nearing opposition and I had a chance to photograph it last night finally in excellent seeing conditions! 🧪🔭 #astrophotography
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SETI Institute @setiinstitute.bsky.social · 24/09/2026
#PPOD: Roman has opened its eyes! These fuzzy rings are the first photons of starlight captured by the Nancy Grace Roman Space Telescope’s 300-megapixel Wide Field Instrument. And yes, they’re supposed to look like that—for now. 🧪 🔭
This test image captures the very first photons of starlight to reach the Wide Field Instrument on NASA’s Nancy Grace Roman Space Telescope. Roman’s primary science instrument has opened its eyes to the universe for the first time, revealing a sea of out-of-focus stars, each spread out over many thousands of pixels. The image, which zooms into one detector and zooms again to a single star in the insets, offers a baseline the Roman team will work from to align the telescope’s optics and tune the focus.
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Benjamin Pope @benjaminpope.bsky.social · 23/09/2026
Australian/NZ students - the call is open for applications to do a fully-funded MRes and/or PhD at Macquarie next year! We have an awesome department, campus, and cool projects. Submit an Expression of Interest here for projects across astro/physics/maths/stats: mq-maps-domestic-eoi.netlify.app
mq-maps-domestic-eoi.netlify.app
Domestic research EOI · Macquarie University
Express your interest in a Master of Research or PhD at Macquarie University's School of Mathematical and Physical Sciences. Domestic scholarship round, Session 1 2027.
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Kevin Hardegree-Ullman @kevinkhu.bsky.social · 10/09/2026
In #exoplanet transit land, we often seek planets further out in their orbit. In direct imaging land, it's all about pushing closer in. This new study from @caltechipac.bsky.social VGSRF @jayke.io finds a new close-in candidate in the classic HR 8799 system!
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Jayke Samson Nguyen @jayke.io · 10/09/2026
Hot off the press! Via the magic of differentiable forward modeling and of non-redundant masking on JWST we may have found a new exoplanet! One of the most challenging papers I've written, but I'm glad its finally out! Submitted to AJ, pending peer review. arxiv.org/abs/2609.10507
arxiv.org
A Candidate Innermost Fifth Planet In the HR 8799 System Revealed By JWST NIRISS Aperture Masking Interferometry
We detect a candidate fifth planet in the HR 8799 system, directly imaged with the JWST/NIRISS Aperture Masking Interferometer (AMI). The detected source lies just above a $3σ$ contrast curve at a con...
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Shashank Dholakia @astroshashank.bsky.social · 09/09/2026
Saturn season is back on (and so are its rings)! Here is my first attempt this year from a few nights ago. The Cassini division in the rings is about the width of US or Australia and under an arcsec wide, requiring pretty good focus and collimation to resolve. 🧪🔭 #astrophotography
A picture of the planet Saturn showing the rings at a moderate tilt. The Cassini division is visible as a gap in the rings most easily visible at ansae (towards the edges of the rings from our point of view. A few cloud bands are visible on the planet itself. There is a dark background and a caption on the lower left that says:

Saturn
16" Dob f4 untracked
QHYIII585C
Sept 6 2026
Shashank Dholakia
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Judy Schmidt @geckzilla.bsky.social · 23/08/2026
Fun time. Here's H-alpha from Hubble, and its infrared analogue Paschen-alpha from JWST. If you look closely in the center near the star, you can just make out the front and back of the nebula moving away from each other. It's not flat!
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James Davenport @jradavenport.com · 10/07/2026
A good reminder than when it comes to “space”, astronomers and the actual content of space (eg stars, galaxies, etc) are unfortunately the last consideration
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Benjamin Pope @benjaminpope.bsky.social · 25/06/2026
Advertising international Masters and PhD scholarships in astronomy at Macquarie, one of Australia's leading institutes! Submit an Expression of Interest by 12 July to start your studies in January 2027. We have projects on offer on stars, planets, and galaxies; and instrumentation and data.
aas.org
PhD and Masters of Research Positions in Astronomy and Astrophysics | American Astronomical Society
Macquarie University is seeking outstanding candidates for PhD and Masters of Research scholarships commencing January 2027.
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Remco de Kok @planetremco.bsky.social · 17/06/2026
Another subtlety to take into account when modelling exoplanets. They rotate and have tidal interactions, which modifies the vertical forces on the atmosphere besides gravity. Arnav+Hazra arxiv.org/abs/2606.18100 🧪🔭 #exoplanets
Fancy graphic of a planet and an illustration of what rotation and tides do to it (elongated equator, different force on the atmosphere, opposite to gravity).
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Alex Santerne @alexsanterne.bsky.social · 23/06/2026
⚠️ Today, we are posting on #arXiv not only 1, nor 2, but 3 papers on the fascinating system #HIP41378. This system hosts 6 and maybe 7 planets 🪐. These papers are the results of a long-lasting investigation on this system initially discovered by the K2's mission, reported in 2016. (🧵 1/6 👇)
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Benjamin Pope @benjaminpope.bsky.social · 19/06/2026
Looking forward to having everyone here for Cool Stars in July 2028 - when a total solar eclipse will pass directly over the city centre!
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Shashank Dholakia @astroshashank.bsky.social · 12/06/2026
Forgot to mention in this thread! I have posted a barebones script to correct uncal NIRISS data using the sinusoid we infer in our paper. Would be great to try it on any NIRISS data you have lying around and see what the effects are on your data! #astro #exoplanets 🔭 github.com/shashankdhol...
github.com
GitHub - shashankdholakia/niriss-cal-inl: Calibrating the JWST NIRISS analog-to-digital converter periodic integral nonlinearity
Calibrating the JWST NIRISS analog-to-digital converter periodic integral nonlinearity - shashankdholakia/niriss-cal-inl
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Shashank Dholakia @astroshashank.bsky.social · 11/06/2026
Shout-out to all my collaborators on this paper who made this possible. Especially @benjaminpope.bsky.social for encouraging me to follow these "odd" data quirks
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Shashank Dholakia @astroshashank.bsky.social · 11/06/2026
Thread on our new paper on arxiv today! We stumbled across a weird sinusoidal systematic that we think appears in every observation from the NIRISS instrument on JWST. We derive a correction and see how much it impacts exoplanet spectra. (1/N) #astro #exoplanets 🔭🧪 arxiv.org/abs/2606.11983
arxiv.org
Calibration of an Analog-to-Digital Conversion Nonlinearity in JWST/NIRISS
We quantify an unusual flux-dependent systematic which is periodic in raw counts in flight data from the James Webb Space Telescope's Near Infrared Imager and Slitless Spectrograph (JWST/NIRISS), used...
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Shashank Dholakia @astroshashank.bsky.social · 10/06/2026
Thesis successfully defended!!
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Colin Stuart 🔭 @colinstuartspace.bsky.social · 06/04/2026
A starspot on Zeta Andromedae. That’s a surface feature on a star 181 light years away. #astronomy ⚛️🧪 Image: Roettenbacher et al
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Shashank Dholakia @astroshashank.bsky.social · 31/03/2026
Thank you Ben!! I obviously couldn't have done it without you! Now to space out for a few days
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💀Adina Feinstein PhD 💀 @afeinstein20.bsky.social · 17/03/2026
really exciting work lead by Catriona Murray! TOI-3884 b is a planet on a polar orbit around an M dwarf. The transit has a persistent starspot crossing event. Using JWST, we measured the properties of the starspot and the Prot of the star 👀 arxiv.org/abs/2603.15414 🔭 #astronomy 🌟 #stellarastro
seven panel figure showing different JWST transits of TOI-3884 b with a persistent spot-crossing event. TOI-3884 b orbits the pole of a small M dwarf star. the shape of the spot-crossing event changes slightly between each transit. each subpanel has a graphical representation of what the spot looks like during each transit.
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Jonatan Rudrasingam @astrojonatan.bsky.social · 28/02/2026
My first scientific paper is now public on arXiv! TESS struggles with the brightest stars due to saturation from overexposure. This is unfortunate, because these are the stars that are amenable to photon-hungry follow-up methods, such as spectroscopy or interferometry (1/9) arxiv.org/abs/2602.22472
arxiv.org
Halo Photometry and Asteroseismology for 98 of the Brightest Stars Observed by TESS
The Transiting Exoplanet Survey Satellite (TESS) mission has facilitated studies of asteroseismology, eclipsing binaries, and transits in many stars. However, the brightest stars saturate TESS, yet th...
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Benjamin Pope @benjaminpope.bsky.social · 04/03/2026
Do you already have a Masters? Do you want to do a PhD in exoplanet radial velocity surveys with me at Macquarie University in Sydney? Then have I got an ad for you!
mq.edu.au
Discovering exoplanets with machine learning
Develop a machine-learned model of stellar spectra and instrumental quirks, and use it to discover exoplanets in radial velocity data.
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Shashank Dholakia @astroshashank.bsky.social · 10/02/2026
If you're on the postdoc market for exoplanet/ML applications--strong recommendation to apply for this job at Macquarie, Ben is great!!
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Astrobites @astrobites.bsky.social · 01/02/2026
From Ryan White @astroryan.bsky.social : There are a few locations in the solar system where the push and pull of gravity mellows out and you can orbit in (relative) peace. Read all about these islands of tranquility we call Lagrange points! ⚛️ 🔭 ☄️ 🧪 astrobites.org/2026/01/29/w...
astrobites.org
What’s the (Lagrange) point?
There are a few locations in the solar system where the push and pull of gravity mellows out and you can orbit in (relative) peace. Read all about these islands of tranquility we call Lagrange points!
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CosmicRami 🏳️‍🌈🏳️‍⚧️ @rami.spaceaustralia.com · 30/12/2025
Stories from #SpaceAustralia in 2025: Checking out the God of Chaos — Apep — using JWST and the VLT. This unique triple stellar system is wild! Some nice work on one of the papers here led by fellow Macquarie University student Ryan White! 🔭
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Shahrin Ahmad (Shah) @shahgazer @shahgazer.bsky.social · 05/12/2025
6 days of sunspots evolution. AR4296 and AR4294 OK, this is getting really tricky to arrange. :-} #astronomy #astrophotography
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Shashank Dholakia @astroshashank.bsky.social · 02/12/2025
One thing I will miss about UQ is the incredible biodiversity on campus. Thread of all the animals I photographed yesterday along one stretch of railing about 10m long. (warning to the squeamish about bugs) Starting with this bronze hopper (Helpis minitabunda): (1/N) #bugsky #nature #spidersky 🌿
Jumping spider with four big eyes visible inside a webbed cave
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Astronomy Picture of the Day 🪐 @apod.shinyakato.dev · 24/11/2025
🔭 Apep: Unusual Dust Shells from Webb Image Credit: NASA, ESA, CSA, STScI, JWST; Science: Y. Han (Caltech), R. White (Macquarie U.); Image Processing: A. Pagan (STScI) apod.nasa.gov/apod/ap25112...
A starfield has a large and unusual red and orange nebula in the middle. The nebula seems to contain not only swirls but also nearly transparent shells. Please see the explanation for more detailed information.
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Shashank Dholakia @astroshashank.bsky.social · 20/11/2025
I love this way of explaining papers!! Check this out by @astroryan.bsky.social !
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Ryan White @astroryan.bsky.social · 19/11/2025
Very excited to share the NASA/ESA/STScI press release of our team's work on Apep! It's a terrific writeup, complete with a brand new beautiful visualisation of the nebula geometry. 1/? ⚛️🔭🧪 science.nasa.gov/missions/web...
science.nasa.gov
Webb First to Show 4 Dust Shells 'Spiraling' Apep, Limits Long Orbit - NASA Science
NASA’s James Webb Space Telescope has delivered a first of its kind: a crisp mid-infrared image of a system of four serpentine spirals of dust, one expanding
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Shashank Dholakia @astroshashank.bsky.social · 11/11/2025
More h-alpha solar timelapses. Here's a loop of plasma twisting off AR4247 from yesterday around 21:30UTC. This might have been part of a small C-class flare. I think it looks like a tornado on the Sun! 🔭 #astronomy #astrophotography
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Dr. Craig DeForest ☀️ @craig.deforest.org · 31/10/2025
This is exactly the reason every mission and scientist should have a wide-open data policy! PUNCH has specific science objectives (looking at the solar wind) – but in the right hands the data can reveal amazing things NOT part of our original science. Giving those hands access is best for all. ☀️🔭🧪
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Benjamin Pope @benjaminpope.bsky.social · 28/10/2025
Absolutely delighted to read this news after an anxious wait - Christian Schwab and I will be looking for a postdoc on extremely precise radial velocities at Macquarie soon! Congratulations to everyone on what looks like an unusually large haul of projects for astronomy.
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Shashank Dholakia @astroshashank.bsky.social · 27/10/2025
Really cool astrobite about a really cool paper!
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Shashank Dholakia @astroshashank.bsky.social · 27/10/2025
My attempt at Comet A6 Lemmon from subpar conditions last night. Wispy clouds still visible in the final image. Was surprisingly bright, p sure I could see it with the unaided eye! Easy through binocs. Canon R5, RF100mm f2.8 19 images, ISO 800, 30s f3.2 🔭 #astronomy #comet
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Shashank Dholakia @astroshashank.bsky.social · 19/10/2025
1.5 hour timelapse of the Sun in hydrogen-alpha. I set this up quite late in the day and the Sun was pretty quiet so I was surprised how much evolution is visible in the prominences, granulation and the active region. I'll have to try more of this. Video is set to loop forwards, then in reverse 🔭
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Benjamin Pope @benjaminpope.bsky.social · 14/10/2025
In a companion paper, PhD student @maxecharles.bsky.social applies this to reconstructing complex images, not just fields of dots. We apply a regularised maximum likelihood method to restore clean, diffraction limited imaging by fitting directly to pixel level data.
arxiv.org
Image reconstruction with the JWST Interferometer
Flying on board the James Webb Space Telescope (JWST) above Earth's turbulent atmosphere, the Aperture Masking Interferometer (AMI) on the NIRISS instrument is the highest-resolution infrared interfer...
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Benjamin Pope @benjaminpope.bsky.social · 14/10/2025
In the first paper Louis Desdoigts (ex PhD in my group, now Leiden postdoc) learns a model for the entire AMI system's optical physics together with a neural network 'effective detector model' the sensor, which suffers from a serious 'brighter-fatter effect' that blurs images at the pixel level.
arxiv.org
AMIGO: a Data-Driven Calibration of the JWST Interferometer
The James Webb Space Telescope (JWST) hosts a non-redundant Aperture Masking Interferometer (AMI) in its Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument, providing the only dedicate...
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Benjamin Pope @benjaminpope.bsky.social · 14/10/2025
Thrilled to have two years' of work out, in a pair of papers led by @gradientrider.bsky.social and @maxecharles.bsky.social. We've built a data-driven calibration of the James Webb Interferometer to near its fundamental limits for high-res imaging - explainer at @aunz.theconversation.com!
theconversation.com
How we sharpened the James Webb telescope’s vision from a million kilometres away
The only Australian hardware on board the legendary telescope is starting to fulfil its duties.
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George Monbiot @georgemonbiot.bsky.social · 08/10/2025
ME/CFS is a devastating condition that has long been denied, dismissed, psychologised and underdiagnosed. Research is at last starting to catch up with it, with glimmers of hope for those who have been left untreated for so long. There's a huge BUT coming ...🧵 www.theguardian.com/society/2025...
theguardian.com
Scientists develop first ‘accurate blood test’ to detect chronic fatigue syndrome
Research could offer hope for ME patients – but some experts urge caution and say more studies needed
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Sabina Sagynbayeva @sabinastro.bsky.social · 03/10/2025
Okay people, welcome my new paper into the world!!! With Isabel Colman and @farrwill.bsky.social arxiv.org/abs/2510.02255
arxiv.org
Rotation Periods for Stars in Open Cluster NGC 6819 From Kepler IRIS Light Curves
We present an updated catalog of stellar rotation periods for the 2.5 Gyr open cluster NGC 6819 using the Kepler IRIS light curves from superstamp data. Our analysis uses Gaussian Process modeling to ...
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Shashank Dholakia @astroshashank.bsky.social · 06/10/2025
And as a bonus, here's a false-color composite of the same. Blue is mapped to all of visible, green is infrared beyond 850nm, and red is the methane band at 889nm. 🔭 #astrophotography #saturn
An azure planet on a stark black background with neon orange-pink rings seen nearly edge-on.
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Shashank Dholakia @astroshashank.bsky.social · 06/10/2025
Been imaging Saturn while its rings are nearly edge-on and tried some infrared filters. At this 889nm methane band, Saturn strongly absorbs light, whereas its rings scatter equally across wavelengths. Also a good visual demo of how astronomers measure exoplanet atmospheres! 🔭🧪 #astrophotography
Three images of Saturn from top to bottom: First, a standard RGB color image showing the rings nearly edge-on at about a 30 degree angle. Middle, a black and white image similar to above, but a little sharper taken with a filter that allows only wavelengths longer than 850nm. Lastly, at bottom, the rings seen as starkly white and the planet dark. This is a very narrow wavelength range of about 20nm centered on 889nm where methane absorbs light, making Saturn itself appear dark and the rings bright.
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Kevin J. Kircher @kevinjkircher.com · 04/10/2025
Sometimes I think about how from 1935-1975ish, Bell Labs produced an insane amount of revolutionary science and technology, including 11 Nobel Prizes, the transistor, UNIX, C, the laser, the solar cell, information theory, etc. The secret? Provide scientists with ample, steady, no-strings funding.
sites.stat.columbia.edu
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Kevin J. Kircher @kevinjkircher.com · 04/10/2025
Research also shows that spreading smaller amounts of funding out over more researchers generally delivers better scientific outcomes per dollar spent than focusing bigger grants on fewer researchers. journals.plos.org/plosone/arti...
journals.plos.org
Big Science vs. Little Science: How Scientific Impact Scales with Funding
Agencies that fund scientific research must choose: is it more effective to give large grants to a few elite researchers, or small grants to many researchers? Large grants would be more effective only...
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Mychal Threets @mychal3ts.bsky.social · 01/10/2025
There have been two hosts in the history of Reading Rainbow. The Legend of Literacy, LeVar Burton! And... me, Mychal Threets, a librarian 🥹🤯 I am a reader, a librarian because LeVar Burton and Reading Rainbow made us believe and see we belong in books, we belong everywhere ✨ youtu.be/e7es7qdWVnU
Smiling Mychal with hands raised wears an outer space shirt in a library. It is a still from an episode of Reading Rainbow.LeVar Burton smiles with hands behind his head as he lies down on a colorful pile of books. ENEMY PIE book rests on his chest.
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Abode Press @abodepress.bsky.social · 01/10/2025
Happy Pub Day to Earth and Earth-like Planets by Devaki D. Devi 🥳 Earth and Earth-like Planets is officially out for publication! 🧡 All pre-orders will be shipped as soon as possible.📦 If you haven't ordered your copy yet, you can purchase one here: www.abodepress.com/product-page...
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Benjamin Pope @benjaminpope.bsky.social · 01/10/2025
This work owes a lot to ideas of and conversations with Rodrigo Luger, Keaton Burns, Geoff Vasil, and Ben Roberts, and it's been a really fun project with Shashank! ... and Shashank is on the postdoc market now, so if you're working on stars and planets, Jax, imaging science and applied maths...
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Shashank Dholakia @astroshashank.bsky.social · 01/10/2025
Reposting for the #astro feed! 🔭
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Shashank Dholakia @astroshashank.bsky.social · 01/10/2025
New paper by me and @benjaminpope.bsky.social! How well can we map a star using optical interferometry? This is just a submitted preprint at the moment--comments and questions welcome! (1/N) arxiv.org/abs/2509.25433
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