John Forbes
redshiftless.bsky.social
John Forbes
@redshiftless.bsky.social
Astronomer in Aotearoa/New Zealand at the University of Canterbury.

Pusher of pixels, pens, arrays, and computer keys.

www.johncforbes.com
Pinned
The Galaxy is full of streams of interstellar objects!

Explainer thread below from @astrokiwi.bsky.social

🔭 🧪
Reposted by John Forbes
Ohio State astronomy is still waiting to see what happens with the federal funding landscape before deciding whether to proceed. With programs that are still TBD, I recommend waiting right now because *application fees do not get refunded if they decide to cancel after you have already paid*!!
So far the astronomy PhD programs that have cancelled admissions are Washington, Michigan State, and Case Western.
Sad to see the University of Washington Astronomy Department has suspended graduate admissions for the 2026-2027 Academic Year. astro.washington.edu/graduate-adm...
October 9, 2025 at 12:45 AM
More hostility than I was expecting from a planter!
September 15, 2025 at 11:29 PM
Incredible stuff happening on wikipedia
August 27, 2025 at 1:39 PM
PSA to scientists: Google calculator appears to no longer do basic unit conversion correctly!

n.b. the correct answer here is 223.4 Myr, a factor of about 60 larger than Google's answer.

🔭 🧪
August 4, 2025 at 3:08 AM
Reposted by John Forbes
Crew-11 lifts off from Florida on their way to the International Space Station.

The heat signature from the launch could be seen from GOES-18.
August 1, 2025 at 5:17 PM
Reposted by John Forbes
Cumulus clouds swirl along the Gulf Coast.

This mesmerizing view captured yesterday by GOES-19.
July 28, 2025 at 6:42 PM
Reposted by John Forbes
I wrote about Rubin again, this time about the telescope's capacity to find potentially dozens of interstellar objects.

It's going to be wild, as one astronomer put it, "like old-fashioned astronomy: Find the thing, point telescopes at it, argue about it."
www.nationalgeographic.com/science/arti...
Are interstellar objects proof of alien life? This could finally settle the debate.
The Vera Rubin telescope is poised to kick off an explosive era of discovery. "It's like old-fashioned astronomy: Find the thing, point telescopes at it, argue about it. It's going to be fun."
www.nationalgeographic.com
July 24, 2025 at 6:00 PM
Reposted by John Forbes
It's paper day! The first science paper with data from @vrubinobs.bsky.social's survey camera, the mighty LSSTCam, is a VERY quick turnaround of Rubin's observations thus far of interstellar comet 3I/ATLAS. ☄️
Chandler et al., submitted 🔭
A 🧵
NSF-DOE Vera C. Rubin Observatory Observations of Interstellar Comet 3I/ATLAS (C/2025 N1)
We report on the observation and measurement of astrometry, photometry, morphology, and activity of the interstellar object 3I/ATLAS, also designated C/2025 N1 (ATLAS), with the NSF-DOE Vera C. Rubin ...
arxiv.org
July 21, 2025 at 5:28 AM
I don't know about "the best," but my April Fool's rant is my personal contribution to this genre. arxiv.org/abs/2003.14327
July 16, 2025 at 1:22 AM
Reposted by John Forbes
It's paper day! We use our Ōtautahi-Oxford model of the Galaxy's interstellar object population to understand the origins of 3I/ATLAS, from only its velocity
@astrohopkins.bsky.social, Dorsey, @redshiftless.bsky.social, @astrokiwi.bsky.social, @chrislintott.bsky.social & Leicester, submitted
A 🧵🔭
From a Different Star: 3I/ATLAS in the context of the Ōtautahi-Oxford interstellar object population model
The discovery of the third interstellar object (ISO), 3I/ATLAS (`3I'), provides a rare chance to directly observe a small body from another Solar System. Studying its chemistry and dynamics will add t...
arxiv.org
July 9, 2025 at 3:29 AM
July 2, 2025 at 3:38 AM
It's my favorite time of the year: new black-footed ferret kits born at the National Zoo and the return of ferretcam!

nationalzoo.si.edu/webcams/blac...
June 5, 2025 at 9:31 AM
Looks like a promising night for aurora chasing
June 1, 2025 at 4:56 AM
As far as I can tell this month is just 8 deadlines in a trenchcoat.
May 13, 2025 at 12:59 PM
Reposted by John Forbes
May 10, 2025 at 10:07 AM
Reposted by John Forbes
Astronomers have found thousands of planets outside the solar system. All of them are, to my knowledge, garbage. Happy Earth Day to the only good one 🌍
April 22, 2025 at 12:44 PM
Reposted by John Forbes
𝗡𝗼, 𝗮 𝗯𝗶𝗼𝘀𝗶𝗴𝗻𝗮𝘁𝘂𝗿𝗲 𝘄𝗮𝘀 𝗻𝗼𝘁 𝗷𝘂𝘀𝘁 𝗱𝗲𝘁𝗲𝗰𝘁𝗲𝗱 𝗶𝗻 𝗞𝟮-𝟭𝟴𝗯'𝘀 𝗮𝘁𝗺𝗼𝘀𝗽𝗵𝗲𝗿𝗲.

K2-18b is back in the news, now with a bold claim that biosignature molecules (DMS and/or DMDS) have been 'detected at 3σ'.

Most exoplanet astronomers are extremely sceptical about these claims, let's see why (1/n).

🔭🧪🪐 #exoplanet
April 17, 2025 at 4:08 PM
New paper!

High-order epicyclic description of orbits in spherically-symmetric potentials (plus vertical oscillations in a disk).

My love of epicycles is so notorious that the postgraduates made this meme
April 15, 2025 at 10:34 AM
Ōtautahi YIMBY’s assemble!
If you haven't already the Christchurch Annual plan consultation closes tomorrow! Check out Greater Ōtautahi's submission guide if you need a place to start!

Links in the comments below!
March 27, 2025 at 8:38 AM
I have GOT to stop making small talk about the "elevators"
March 19, 2025 at 4:18 AM
Reposted by John Forbes
It's paper day! Led by grad students Rosemary Dorsey and Matthew Hopkins, we bring you a beautifully detailed study of how interstellar objects will be visible to @vrubinobs.bsky.social 🔭🧪
The visibility of the Ōtautahi-Oxford interstellar object population model in LSST
With a new probabilistic technique for sampling interstellar object (ISO) orbits with high efficiency, we assess the observability of ISOs under a realistic cadence for the upcoming Vera Rubin Observa...
arxiv.org
February 25, 2025 at 8:56 AM
Reposted by John Forbes
The champions of Free Speech are now forcing scientists to retract submitted publications until they can be checked for the appearance of “forbidden terms.”
BREAKING NEWS: CDC orders mass retraction and revision of submitted research across all science and medicine journals. Banned terms must be scrubbed.

Goes beyond MMWR +other CDC pubs. Applies to research already submitted to top medical journals.

Take a look.
open.substack.com/pub/insideme...
BREAKING NEWS: CDC orders mass retraction and revision of submitted research across all science and medicine journals. Banned terms must be scrubbed.
Any unpublished manuscript mentioning certain topics, including gender and "LGBT," must be pulled or revised.
open.substack.com
February 2, 2025 at 12:42 AM
Ooh this is a very nice way to grok the Solar Neighborhood 🔭
Feeling nostalgic about my Fly app (gruze.org/fly).

I was working with astronomer Richard Smart, who lead the team that created the Gaia Catalogue of Nearby Stars (out to 100 parsecs) and we kept coming up with more features to add.
January 20, 2025 at 9:14 AM
Chuffed by the YIMBY-adjacent messaging in my 2-yr-old’s current favorite book
January 5, 2025 at 3:37 AM
Reposted by John Forbes
My colleagues are using ChatGPT to source data and plot analyses for them. I'm literally reviewing papers written this way.

Meanwhile....
December 31, 2024 at 7:38 AM