Terry Phan

A Search for Planet Nine with IRAS and AKARI Data The outer solar system is theoretically predicted to harbour an undiscovered planet, often referred to as P9. Simulations suggest that its gravitational influence could explain the unusual clustering ...

👀 Usually, this type of article concludes with "we place strong upper limits on any...". This one: "After image inspection, we found one good candidate..." That sounds like a good start! 🪐🔭

Planet Nine Candidate from IRAS and AKARI Data Researchers for objects that moved slowly between IRAS and AKARI detections. IRAS and AKARI are far-infrared, all-sky surveys completed 23 years apart. They looked in the Kuiper belt. They produced all possible candidate pairs including one IRAS source and one AKARI source whose angular separations were limited between 42′ and 69.6′, corresponding to the heliocentric distance range of 500 – 700 AU and the mass range of 7– 17M⊕. There were 13 candidate pairs obtained after the selection criteria. After image inspection, they **found one good candidate** , of which the IRAS source is absent from the same coordinate in the AKARI image after 23 years and vice versa. However, AKARI and IRAS detections are not enough to determine the full orbit of this candidate. 9 detections are required to evaluate a linked Keplerian orbit with improved processing speed and reduce the number of false positives. They will need the new and better space telescopes to re-examine the candidate to see if they can confirm that is planet 9 or not. The IRAS and AKARI detections alone are not enough to decide a precise orbit. The DECam, with a large field of view, is a prospective option for the follow-up observation. It enables the possibility of detecting faint moving objects even in optical wavelengths and determining the full orbit of our candidate, since the exposure time to observe targets as faint as 26 AB mag at DECam is approximately one hour. The verification of Planet Nine’s existence via future observational studies will contribute to our understanding of the evolution and structural dynamics of the solar system. Brian Wang Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology. Known for identifying cutting edge technologies, he is currently a Co-Founder of a startup and fundraiser for high potential early-stage companies. He is the Head of Research for Allocations for deep technology investments and an Angel Investor at Space Angels. A frequent speaker at corporations, he has been a TEDx speaker, a Singularity University speaker and guest at numerous interviews for radio and podcasts. He is open to public speaking and advising engagements.

Planet Nine Candidate from IRAS and AKARI Data Researchers for objects that moved slowly between ...

https://www.nextbigfuture.com/2025/05/planet-nine-candidate-from-iras-and-akari-data.html

#Science #Space #Technology #astronomy #science #space #technology

Result Details

Check out this popular article in #PASA Chen, Goto, Yamamura, Nakagawa, Wu, Phan, Hashimoto, Uno, Ho, Kim: "A Far-Infrared Search for Planet Nine Using AKARI All-Sky Survey"
Read for free thanks to #OpenAccess
cup.org/44rkqbk

@astrominh.bsky.social I just wonder after submission, if the Editorial Board makes a decision that the paper is not eligible for publication in PASA Letter, do authors have to manually submit their paper again to the usual PASA?

The PASA Editorial Board and I are proud to announce PASA is now accepting Letter submissions!

@plutokiller.com I'm just wonder if it's possible that the orbital clustering of minor KBOs is driven by the gravity of two planets? Have you ever simulated this scenario?

@plutokiller.com Although we haven't estimated it yet in this work, I would say that all IRAS and AKARI sources before pairing up were required to have high flux quality (fqual value) at 60, 65, 90, and 100 micron. By this way we can remove unreliable sources from the beginning.

@mbmocam.bsky.social Using Machine Learning to speed up the data analysis is a good idea. We'll consider applying it to our next studies.

@mbmocam.bsky.social JWST can be used for deeper researches on P9 unless we know where it is on its orbit. Due to the uncertainty of P9's heliocentric distance, I think it's currently better to search by using all-sky surveys with larger field of view.

@astrafoxen.bsky.social
Anyway, thank you for raising an important point. It is worth checking and discussing in more detail in the follow-up studies.

@astrafoxen.bsky.social
However, the angular resolution of IRAS is 1.2’ at 60um. Within a radius of 1.2', there are even more sources that raise the difficulty in determining which source is the true counterpart of our IRAS source.

@astrafoxen.bsky.social
To be specific, in Section 6 of that paper, they classified objects based on the AKARI-IRC or AKARI-FIS detections, which are absent in the output result. Additionally, the WISE image shows nearby sources around the IRAS position.

@astrafoxen.bsky.social
The IRAS source in our candidate indeed matches with a WISE source when checking the IRAS-PSC/FSC Combined Catalogue (Abrahamyan et al. 2015). However, the classification method presented in that paper seems to be insufficient to conclude that our IRAS source is a galaxy.

Having meticulously identified this candidate from two million IRAS+AKARI objects, I believe it still merits immediate and thorough follow-up observations to determine its planetary status and orbital characteristics.

Thank you for a very important point. While our candidate is at a higher orbital inclination than predicted by your simulations, however, the detection of a giant planet would still be an interesting discovery regardless of its precise orbit.

Dear Prof. Brown, I’m Terry - the 1st author of the paper. Thank you for reading our paper! I started this research motivated by your paper and presentations. It is a great pleasure to have your comments on my paper.

Astronomers searching for Planet Nine find possible hints of different planet Analysis of decades-old data yields a faint, meandering point of light beyond Neptune—but many experts are skeptical

Could astronomers have found the elusive Planet Nine - or accidentally disproven it?🪐 Find out in my story for @science.org! www.science.org/content/arti...

A Search for Planet Nine with IRAS and AKARI Data
https://arxiv.org/pdf/2504.17288
Terry Long Phan, Tomotsugu Goto, Issei Yamamura, Takao Nakagawa, Amos Y.-A. Chen, Cossas K.-W. Wu, Tetsuya Hashimoto, Simon C.-C. Ho, Seong Jin Kim.

A Search for Planet Nine with IRAS and AKARI Data The outer solar system is theoretically predicted to harbour an undiscovered planet, often referred to as P9. Simulations suggest that its gravitational influence could explain the unusual clustering ...

I have a couple of thoughts about the new paper the finds a candidate Planet Nine in some old data. First, it is difficult to tell how seriously to take this because a false alarm probability is never discussed, and second, if it is real, it is not Planet Nine. Read on:
🧵🔭🧪

arxiv.org/abs/2504.17288