John Forbes
redshiftless.bsky.social
John Forbes
@redshiftless.bsky.social
1.3K followers 1.5K following 79 posts
Astronomer in Aotearoa/New Zealand at the University of Canterbury. Pusher of pixels, pens, arrays, and computer keys. www.johncforbes.com
Posts Media Videos Starter Packs
Pinned
The Galaxy is full of streams of interstellar objects!

Explainer thread below from @astrokiwi.bsky.social

🔭 🧪
I think the "abundance agenda" is vague enough that some people could read it that way, but my read is that we need to build a lot of solar/batteries/transmission (to keep fossil fuels in the ground!), and a lot of old-school environmentalists are opposed to that because it involves building stuff.
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...
More hostility than I was expecting from a planter!
Re the CRs: the age might buy you a factor of 2 relative to the solar system, but there may be a larger effect (in the same direction!) - 3I's orbit sends it further above the galactic midplane -> less B field -> more CRs

(adapted from an argument made in this paper: arxiv.org/abs/2509.04165).
Incredible stuff happening on wikipedia
It is wild how many outdoor cats there are in NZ. Everyone loves the native birds, but the outdoor cat culture is really ingrained.
Obviously peer reviewed vs. not can be an issue, but in this particular case the data in the paper seems to have been completely fabricated. I think it's fair to say that peer review generally operates on assumptions of good faith, so fake data will often make it through.
They don't seem to sell many ads on these calculator-style searches, so perhaps costing google money is the most ethical choice 🤷 (if it worked lol).

But seriously, not a bad point!
Yeah, could be. Google has worked well for the past decade, so it feels like the end of an era.
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.

🔭 🧪
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.
Reposted by John Forbes
Cumulus clouds swirl along the Gulf Coast.

This mesmerizing view captured yesterday by GOES-19.
Reposted by John Forbes
Reposted by John Forbes
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
If this holds up it will be the 3rd interstellar object (comet or asteroid from another star system). Not every day we get to increase the sample by 50%!

168 hr arc = observed over a period of 1 week so far, and e~9 meaning convincingly interstellar (anything >~1 is not bound to the Sun).
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...
Looks like a promising night for aurora chasing
As far as I can tell this month is just 8 deadlines in a trenchcoat.
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 🌍
Bad stats (and not a convincing biosignature in the first place) bsky.app/profile/dist...
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
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