A trio of scientists have published a paper that explains how they found a dwarf planet in a database.

As explained in a pre-press [1]paper [PDF] titled “Discovery of a dwarf planet candidate in an extremely wide orbit: 2017 OF201”, in 2014 scientists used Chile’s Blanco 4m telescope for a project called the [2]Dark Energy Camera Legacy Survey (DECaLS) that observed extragalactic objects.

The authors were aware of similar studies, felt they could also contain evidence of faint objects in our own solar system, but couldn’t find any previous work that did so by analyzing DECaLS data.

[3]

They therefore created an algorithm to search the DECaLS database and compare the images it contains and assert that effort yielded evidence of a dwarf planet. The authors promise a paper about their algo is under way and [4]told The New York Times their work involved “a lot of computation.” It looks like they did that on-prem as the paper states work on the paper “was substantially performed using the Princeton Research Computing resources … and the Office of Information Technology’s Research Computing.”

[5]NASA's New Horizons probe scores extended vacation in Kuiper Belt

[6]Venus has a quasi-moon and it's just been named 'Zoozve' for a sweet reason

[7]Four out of five Uranus moons likely to have ocean under crust

[8]Hubble telescope spots tiniest water-rich world in orbit

Whatever machines did the number crunching, the results suggest OF201 has a diameter of ∼700 kilometers, about 30 percent smaller than the dwarf planet [9]Sedna and considerably smaller than both Eris and Pluto (around 2,300km apiece). The authors think the candidate dwarf planet’s orbit brings it close to Pluto – at about 45 Astronomical Units (AU, the distance from Earth to Sol), before it swings out beyond 1,600 AU during its 25,000 year journey around the Sun.

The authors, Sihao Cheng, Jiaxuan Li, and Eritas Yang, who work across Princeton University’s Department of Astrophysical Sciences and Institute of Advanced Studies, and Canada’s Perimeter Institute, also consider Planet 9 – the hypothetical substantially-sized planet located in the outer solar system that some scientists [10]suggest could explain cometary orbits and the disposition of the Kuiper Belt.

[11]

The paper doesn’t have great news for Planet 9 believers, because it suggests OF201’s orbit “lies well outside the clustering observed in extreme trans-Neptunian objects, which has been proposed as dynamical evidence for a distant, undetected planet.”

The authors have acknowledged that the data used in their study was freely available to all, and noted that’s a fine and lovely thing because it means more similar discoveries are eminently possible. ®

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[1] https://arxiv.org/pdf/2505.15806

[2] https://www.legacysurvey.org/decamls/

[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aDmBtusJ7udKQ62d598JYwAAAUI&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0

[4] https://www.nytimes.com/2025/05/29/science/dwarf-planet-nine-discovery.html

[5] https://www.theregister.com/2023/10/02/new_horizons_mission_extension/

[6] https://www.theregister.com/2024/02/13/venusian_quasi_moon_named_zoozve/

[7] https://www.theregister.com/2023/05/05/four_out_of_five_uranus/

[8] https://www.theregister.com/2024/01/27/hublbe_water_world/

[9] https://www.theregister.com/2012/04/05/trans_neptunian_objects/

[10] https://www.theregister.com/2014/03/10/planet_x_does_not_exist/

[11] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aDmBtusJ7udKQ62d598JYwAAAUI&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0

[12] https://whitepapers.theregister.com/