Help astronomers name the largest unnamed world in our Solar System.
Gemini Observatory, Hawai'i
Meg is a planetary scientist and astronomer. She currently is an assistant scientist at Gemini Observatory based in Hilo, Hawai'i. Her research focuses on the small resevoirs in the outer Solar System, Mars, and exoplanets. She studies how planets and building blocks form and evolve, applying ground-based surveys to probe our Solar System’s small body reservoirs and citizen science to mine large datasets for Solar System science. Meg is currently involved in the Planet Four citizen projects ( Planet Four, Planet Four: Terrains , Planet Four: Ridges), and Comet Hunters citizen science project. As a graduate student at Caltech, Meg helped run the Palomar Distant Solar System Survey which discovered 2007 OR10. She has also helped discover and characterize PH1-b: the first exoplanet found in a four star system.
Mike Brown is the Richard and Barbara Rosenberg Professor of Planetary Astronomy at the Caltech. and has been on the faculty there since 1996. He specializes in the discovery and study of bodies at the edge of the Solar System. Among his numerous scientific accomplishments, he is best known for his discovery of Eris, the most massive object found in the solar system in 150 years, and the object which led to the debate and eventual demotion of Pluto from a real planet to a dwarf planet. He is also one of the first proponents of Planet 9, a proposed Neptune-sized body lurking in the outer Solar System beyond Neptune. Mike was the principal investigator of the Palomar Distant Solar System Survey which discovered 2007 OR10. Mike is also author of "How I Killed Pluto and Why It Had It Coming", an award winning best selling memoir of the discoveries leading to the demotion of Pluto.
Yale University, Connecticut
David is a research scientist at Yale University’s Center of Astronomy and Astrophysics and Physics Department. He is the co-discover of Eris, Haumea, Makemake, and other dwarf planets in the outer Solar System. Since 2003, David has been the principal specialist for the QUEST camera. David was a collaborator on the Palomar Distant Solar System Survey which utilized the QUEST camera. David has also led projects to survey the solar phase curves and rotation states of the largest KBOs and other icy bodies in the solar system and has been a co-investigator in surveys for nearby bright supernovae and studies of Active Galactic Nuclei (AGN) variability.
2007 OR10's orbit places it in the Kuiper belt, the sea of icy planetesimals that orbit beyond Neptune. Over 3000 Kuiper belt objects (KBOs) are known to date. 2007 OR10 resides on an elliptical orbit. It makes its closest approach to the Sun at 33 au (1 au is the mean distance between the Earth and Sun), and its furthest point from the Sun is at a distance of 101 au. 2007 OR10 has a typical orbit of a scattered disk Kuiper belt object, one that was emplaced into the Kuiper belt during the migration of our Solar System's giant planets, including Neptune, through gravitational scattering. 2007 OR10 appears to be in the 10:3 mean motion resonance with Neptune (2007 OR10 completes 3 orbits for every 10 Neptune orbits).
2007 OR10 was discovered on July 17, 2007 as part of the Palomar Distant Solar System Survey that was searching for distant bodies in the Kuiper belt and beyond. The survey employed the 48-inch Samuel Oschin telescope located at Palomar Observatory in Southern California. Moving Solar System bodies were discovered, by taken an image on one night and returning to take a second image ~1-2 hours later and then coming back the next night with another pair of images, with the frames separated by ~1-2 hours. For more information, you can read the research paper summarizing the survey.
Image: Star trails and the Samuel Oschin Telescope - Credit: Palomar/Caltech
We know from previously measured densities/bulk internal compositions of bodies of similar size to 2007 OR10, that the body is likely a mixture of ice and rock. Near-infrared spectroscopy has revealed that there are large quantities of pure water ice and possibly traces of methane ice on 2007 OR10's surface. 2007 OR10 has one of the reddest surfaces ever found in the Kuiper belt. It is suspected that its red hue comes from the irradiation of the trace amounts of methane ice on its surface (similar to dwarf planet-sized Quaoar). It is suspected that water ice on 2007 OR10's surface indicates past cryovolcanism earlier on in the planetesimal's history where water from the interior coated and froze on the surface. For more information, you can read the research paper summarizing this result.
Image: Artist rendition of 2007 OR10 - Credit: NASA
We don't quite know 2007 OR10's size accurately, but a good guess is that 2007 OR10 is ~ 1250 km in diameter. That makes it smaller than Pluto and Eris and some of the other Pluto-sized KBOs, but that size estimate earns 2007 OR10 a spot on the list of the top 10 largest KBOs. 2007 OR10 is likely large enough for gravity to make it round, making it a candidate dwarf planet.
Image: A Family Portrait of the Largest Kuiper belt Objects - Artist Rendition Credit: Lexicon - based on an a graphic created by: NASA, ESA, and A. Feild (STScI)
In 2016, it was announced that a moon had been discovered orbiting around 2007 OR10 by Csaba Kiss and collaborators using archival data from the Hubble Space Telescope. Many of the large bodies in the Kuiper belt have small moons, including Eris, Haumea, Makemake, and and Quaoar.
Image - Discovery images of 2007 OR10's moon taken by the Hubble Space Telescope - Credit: NASA, ESA, C. Kiss (Konkoly Observatory), and J. Stansberry (STScI)
András Pál and collaborators have measured the rotational light curve for 2007 OR10 thanks to the Kepler spacecraft and NASA's K2 mission . Measuring the brightness of 2007 OR10 over a 19 day period, Pál and collaborators find that 2007 OR10 rotates very slowly with a 44.81 hour rotation period; one of the slowest rotation periods measured in the Kuiper belt.
For more information you can read the research paper about the K2 analysis.
Video - A subset of Kepler's pixels downloaded monitoring where 2007 OR10 was expected to be in K2's observing campaign. This video shows all the observations Kepler took of 2007 OR10 in 2014. The arrow shows the position of 2007 OR10 in each K2 frame over 19 days The motion of 2007 OR10 is caused by Kepler's motion as the spacecraft orbits the Sun. - Credit: Konkoly Observatory/László Molnár and András Pál
A European winter goddess of fertility, rebirth, and women. Holle makes snow by shaking out her bed. She is a patroness of household crafts especially spinning. She is linked to the Yuletide (winter solstice) season associated with mistletoe and holly, evergreen plants bearing red berries. References: , , , , Read more on wikipedia
Part of the Æsir, Vili is a Nordic deity. Vili, together with his brothers Odin and Vé, defeated frost giant Ymir and used Ymir's body to create the universe. Ymir's flesh and bones were forged into the Earth, with Ymir's blood becoming the rivers and oceans. References: , , , .Read more on wikipedia
Voting is now closed. More soon as we tally the votes
We know, it's been a long wait! We've always wanted to have some kind of public involvement in naming 2007 OR10, but we also wanted to know more about the object to give it a name that fits. We've also been busy with research, work, and life (Meg has moved continents multiple times during this period). Thanks to Geert Barentsen who helped create this site for us.
Voting opens on April 9, 2019 at 06:00 AM PDT. Voting ends on May 10, 2019 at 11:59 PM PDT.
Voting lasts for three week. After that we'll quickly announce the results on this site and then formally submit the naming suggestion for the International Astronomical Union (IAU) to consider. Check back soon for updates.
Hopefully. When a planetesimal in the Solar System has a secure orbit, the Minor Planet Center invites suggestions from the discovers for a period up to 10 years. The Minor Planet Center passes the suggested name and justification from the discoverers to the International Astronomical Union's (IAU) Committee for Small-Body Nomenclature which makes the final decision. More details can be found here.
Yes. It is the International Astronomical Union's (IAU) Committee for Small-Body Nomenclature which makes the final decision. More details can be found here. In most past cases, the name suggested by the discoverers as long as it fits the naming guidelines has been taken as the formal name for the Solar System body, but the IAU Committee for Small-Body Nomenclature has the final say to ultimately accept or reject the naming suggestion. So, we think there's a good chance that the naming suggestion with the most votes will become the official name for 2007 OR10. If the top choice is not accepted, we will submit the second most popular choice to the IAU for consideration.
We tried to select deities where there were links to color red and also where there was a theme of inside turning outside or with water ice/snow to connect to the suspected past cryovolcanism coating 2007 OR10 with water ice. Also, we looked for naming suggestions that have connections to other mythological creatures and deities that could be used as naming options for 2007 OR10's moon.
Discovers have a 10 year period from when a minor planet is numbered, has an orbit that is deemed secure by the Minor Planet Center (MPC) and given a permanent number on top of its original desgination, where a name they suggest will have a stronger preference when considered by the IAU. (225088) 2007 OR10 was numbered by the MPC in November 2009. So the discovery team should submit a naming suggestion for 2007 OR10 is November 2019.
Unfortunately, no. We can see about visual magnitude ~8 stars by eye in very dark skies, and the brightness of of 2007 OR10 is about 21st-22nd magnitude.
July 17, 2007, UT in the Palomar Distant Solar System Survey. Pre-recovery observations for 2007 OR10 have been reported to the Minor Planet Center (MPC). Observations of 2007 OR10 from as early as 1985 have been found.
That's the designation that the Minor Planet Center (MPC), which keeps track of discoveries in our Solar System, gave for this Kuiper belt object. You can think of it like the license plate numbers for motor vehicles. All minor planets including Pluto and Eris have an identifier like this.
The Minor Planet Center (MPC) is responsible for keeping track of all the discoveries and orbits for minor bodies in the Solar System. You can learn more about their mission at www.minorplanetcenter.net.
Objects in the Kuiper belt in similar orbits to 2007 OR10 must be given names associated with mythological figures associated with creation. More details on the suggested naming requirements put forth by the International Astronomical Union (IAU) can be found here and here. We tried to find mythologies from across the world that fit the IAU naming criteria and whose origin and characteristics related in some way to the properties we know of for 2007 OR10. We tried to keep in mind that there's a moon that will also need a name. The discovers of 2007 OR10's satellite will have the right to submit a name for the moon, so we looked for naming options for 2007 OR10 where there would also be some suitable related naming options for the moon.
The audio pronunciations of each candidate name are thanks to Øyvind Guldbrandsen (Vili), Ralf Edmund Stranzenbach (Holle), and Quanzhi Ye 叶泉志 (Gonggong), with help from Emily Lakdawalla.
That's great, but we're going to pick the naming suggestion with the most votes from our list of three.
Sorry, not for this vote. We didn't find the moon, so that's up to discovers of S/(225088) 1 to decide how they want to go about selecting a name for their discovery.
Yes, you can vote for your favorite naming suggestion more than once, but we ask that you only vote twice per day so that all participants' voices have a fair chance of being heard.
The IAU has outlined a process for obtaining IAU support/approval for public naming campaigns. We have gone through this process.