Kevin Wagner

Thanks for reading to the end! Please check out Arin's paper and let us know if you have any questions or comments. @danielapai

This allows us to predict the next likely observed collision event in terms of time and separation from the star. With continued monitoring from HST, there's a ~50% chance of observing a third collision by the early 2030s. With JWST, those odds improve significantly.

Highlighting a new paper from UA/LPL Grad Student Arin Avsar that places some of the first constraints on the population of planetesimals (~30-100km asteroids) around young stars! arxiv.org/abs/2603.07376

Shout out to @e_douglas, @exoAS23b, @saturnaxis, and other co-authors for their help, ideas, and support in this study, and thanks to Pete Worden and @brkthroughprize for the motivation to explore this concept. Please reply in the comments if you have any thoughts/questions.

With access to space becoming cheaper, purpose-built observatories are becoming more feasible. For the same budget (or less) than @JimCameron's Avatar movies, which imagined a habited moon around a giant planet around Alpha Cen, this mission could become a reality.

Alpha Centauri A might host a habitable-zone giant planet. If confirmed, any moons orbiting this planet could be among the most promising nearby locations to search for life. Can we detect those moons by carefully monitoring the position of the planet? arxiv.org/abs/2509.13513

This was a very fun project! I’m happy to see the results published today (and now I can finally share this LBTI image!)

I'm happy to share this exciting result that @StewardAstro PhD student @ggdoubleu played a major role in! WISPIT-2b is one of the few known accreting protoplanets, allowing us to directly study how planets form. Read more in the paper from Close et al.: iopscience.iop.org/article/10.384…

@MarioNawfal That orbit fit showed that there's a ~52% probability that the planet (if real) had orbited too close to the star (from our perspective) to be detectable by JWST.

@MarioNawfal There's also a possible earlier sighting of the same planet in 2019. Not quite confirmation, but two detections are stronger than one! This is also how we figured out that it's likely "just hiding" - two detections allowed us to fit an orbit.

WE MAY HAVE FOUND A MONSTER PLANET IN OUR NEIGHBOR'S GARDEN Astronomers think they’ve spotted a gas giant orbiting Alpha Centauri A, our closest sun-like neighbor, just 4.3 light-years away. That’s basically cosmic spitting distance. This world is Saturn’s weight, Jupiter’s size, and parked right in the “habitable zone”… except it’s more like a bouncer kicking out any Earth-like planets that try to move in. James Webb snapped it in 2024 using an interstellar game of peekaboo, blocking the star’s blinding light. Follow-ups in 2025 missed it, but scientists say it’s just hiding and will reappear in 2026. If it’s real, it’s the biggest, closest “maybe-planet” we’ve ever found around a sun twin, and it’s hogging prime cosmic real estate like the galaxy’s ultimate landlord. Source: Science News

UA Press release on Alpha Centauri here: news.arizona.edu/news/alpha-cen…

@Dennis_Gregorio @skyatnightmag I’d have to agree. @JimCameron we might have seen your planet again.

@skyatnightmag Will they be naming this gas giant orbiting in the habitable zone of Alpha Centauri A “Polyphemus”? Seems like they have to. 🤔

Webb may have found a new planet in the habitable zone around the star closest to our Sun skyatnightmagazine.com/news/webb-alph…

@AstroThayne The VLT detection is definitely not a speckle. We had over a dozen nights of data and saw it in every one. Unknown systematic is the only explanation if it’s not a planet. Here’s the VLT campaign split into two independent datasets in two different ways.

@AstroWagner I mean, I still think it's a speckle. But reobserving this is VERY high reward. There have been far far worse uses of telescope time than this with less potential rewards. Let's do some yolo :)

the candidate Alpha Cen planet from JWST ... real or a residual speckle/artifact? Regardless, this should definitely get follow up time.

@AstroThayne 💯

@AstroWagner well that makes the case for DDT time even stronger, yes. Everyone & their cousin has a 3 to 4.5-sigma blip in their data: almost always speckles. But having a pair of suspicious things on the same target from different teams & 'scopes w/ a compatible orbit = v interesting