2007 OR10 Needs A Name. We Suggest Dwarfplanet McDwarfplanetyface

Results of a study combining Kepler observations with Herschel data show that 2007 OR10 is the largest unnamed dwarf planet in our Solar System, and the third largest overall. Illustration: Konkoly Observatory/András Pál, Hungarian Astronomical Association/Iván Éder, NASA/JHUAPL/SwRI

Depending on shifting definitions of what exactly is or isn’t a dwarf planet, our Solar System has about half a dozen dwarf planets. They are: Pluto, Eris, Haumea, Makemake, Ceres, and 2007 OR10.

Even though 2007 OR10’s name makes it stand out from the rest, dwarf planets as a group are an odd bunch. They spend their time in the cold, outer reaches of the Solar System, with Ceres being the only exception. Ceres resides in the asteroid belt between Mars and Jupiter.

Their distance from Earth makes them difficult targets for observation, even with the largest telescopes we have. Even the keen eye of the Hubble Telescope, orbiting above Earth’s view-inhibiting atmosphere, struggles to get a good look at the dwarf planets. But astronomers using the Kepler spacecraft discovered that its extreme light sensitivity have made it a useful tool to study the dwarves.

In a paper published in The Astronomical Journal, a team led by Andras Pal, at Konkoly Observatory in Budapest, Hungary, have refined the measurement of 2007 OR10. Using the Kepler’s observational prowess, and combining it with archival data from the Herschel Space Observatory, the team has come up with a much more detailed understanding of 2007 OR10.

Previously, 2007 OR10 was thought to be about 1280 km (795 miles) in diameter. But the problem is the dwarf planet was only a faint, tiny, and distant point of light. Astronomers knew it was there, but didn’t know much else. Objects as far away as 2007 OR10, which is currently twice as far away from the Sun as Pluto is, can either be small, bright objects, or much larger, dimmer objects that reflect less light.

This is where the Kepler came in. It has exquisite sensitivity to tiny changes in light. Its whole mission is built around that sensitivity. It’s what has made Kepler such an effective tool for identifying exo-planets. Pointing it towards a tiny target like 2007 OR10, and monitoring the reflected light as the object rotates, is a logical use for Kepler.

Even so, Kepler alone wasn’t able to give the team a thorough understanding of the dwarf planet with the clumsy name.

Enter the Herschel Space Observatory, a powerful infrared space telescope. Herschel and its 3.5 metre (11.5 ft.) mirror were in operation at LaGrange 2 from 2009 to 2013. Herschel discovered many things in its mission-span, including solid evidence for comets being the source of water for planets, including Earth.

But the Herschel Observatory also bequeathed an enormous archive of data to astronomers and other space scientists. And that data was crucial to the new measurement of 2007 OR10.

Combining data and observations from multiple sources is not uncommon, and is often the only way to learn much about distant, tiny objects. In this case, the two telescopes were together able to determine the amount of sunlight reflected by the dwarf planet, using Kepler’s light sensitivity, and then measure the amount of that light later radiated back as heat, using Herschel’s infrared capabilities.

Combining those datasets gave a much clearer idea of the size, and reflectivity, of 2007 OR10. In this case, the team behind the new paper was able to determine that 2007 OR10 was significantly larger than previously thought. It’s measured size is now 1535 km (955 mi) in diameter. This is 255 km (160 mi) larger than previously measured.

It also tells us that the dwarf planet’s gravity is stronger, and the surface darker, than previously measured. This further cements the oddball status of 2007 OR10, since other dwarf planets are much brighter. Other observations of the planet have shown that is has a reddish color, which could be the result of methane ice on the surface.

Lead researcher Andras Pal said, “Our revised larger size for 2007 OR10 makes it increasingly likely the planet is covered in volatile ices of methane, carbon monoxide and nitrogen, which would be easily lost to space by a smaller object. It’s thrilling to tease out details like this about a distant, new world — especially since it has such an exceptionally dark and reddish surface for its size.”

Now that more is known about 2007 OR10, perhaps its time it was given a better name, something that’s easier to remember and that helps it fit in with its peer planets Pluto, Ceres, Eris, Haumea, and Makemake. According to convention, the honor of naming it goes to the planet’s discoverers, Meg Schwamb, Mike Brown and David Rabinowitz. They discovered it in 2007 during a search for distant bodies in the Solar System.

According to Schwamb, “The names of Pluto-sized bodies each tell a story about the characteristics of their respective objects. In the past, we haven’t known enough about 2007 OR10 to give it a name that would do it justice. I think we’re coming to a point where we can give 2007 OR10 its rightful name.”

The Universe is vast, and we need some numbered, structured way to name everything. And these names have to mean something scientifically. That’s why objects end up with names like 2007 OR10, or SDSS J0100+2802, the name given to a distant, ancient quasar. But objects closer to home, and certainly everything in our Solar System, deserves a more memory-friendly name.

So what’s it going to be? If you think you have a great name for the oddball dwarf named 2007 OR10, let us hear it in a tweet, or in the comments section.

Dawn Spacecraft’s Dwarf Planet Dance Improves Hubble’s Far-Away View

The Hubble Space Telescope is one of the best observatories humanity has. It’s been operating for nearly 25 years in space, is still highly productive, and is a key element to mission planning for NASA as it sends spacecraft out into the Solar System. When the agency was getting ready to send Dawn to Vesta, for example, it took pictures to help with calibration.

Then Dawn got up close to the dwarf planet in 2011 and found a few surprises — liquid water that possibly flowed temporarily on the surface, for example. And as the spacecraft draws near to Ceres for a close encounter next year, it also will be looking for water — in the form of its atmosphere.

That’s following on from research out of the Herschel Space Telescope published earlier this year, showing that Ceres has a thin water vapor atmosphere surrounding the dwarf planet. It could be producing water similarly to how a comet does, through sublimation, but investigators won’t know much until they get close-up.

“Ceres has some sort of mechanism that’s putting out water vapor and causing a thin, temporary atmosphere,” said Keri Bean, a mission operations engineer at the Jet Propulsion Laboratory who works on Dawn, in a Google+ Hangout yesterday (Dec. 11). “I think that we’re going to try to look into this, and we don’t know what else Ceres will have in store for us.”

Ceres as seen from the Earth-based Hubble Space Telescope in 2004 (left) and with the Dawn spacecraft in 2014 as it approached the dwarf planet. Hubble Credit: NASA, ESA, J. Parker (Southwest Research Institute), P. Thomas (Cornell University), L. McFadden (University of Maryland, College Park), and M. Mutchler and Z. Levay (STScI). Dawn Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA. Photo Combination: Elizabeth Howell
Ceres as seen from the Earth-based Hubble Space Telescope in 2004 (left) and with the Dawn spacecraft in 2014 as it approached the dwarf planet. Hubble Credit: NASA, ESA, J. Parker (Southwest Research Institute), P. Thomas (Cornell University), L. McFadden (University of Maryland, College Park), and M. Mutchler and Z. Levay (STScI). Dawn Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA. Photo Combination: Elizabeth Howell

Dawn is now so close to Ceres that its pictures will soon exceed the best ones Hubble had to offer. The image above (at right) is modest compared to the space telescope, but in a planned photo session Jan. 26 Dawn will have slightly better pictures than Hubble. By Feb. 4 they will be twice as good in quality and then seven times as good Feb. 20.

The spacecraft’s images not only have science purposes, as they let investigators study the surface, but also serve as optical navigation aids. Ceres is a tiny body and hard to navigate to from far away, so as it gets closer these pictures are crucial for Dawn to figure out where to go next.

Dawn will get its close-up of Ceres in the spring when it arrives at the dwarf planet. To get the latest on the mission, check out the entire Google+ Hangout from yesterday.

Dusty Galaxies Shine Across The Universe In New Herschel Survey

While dust is easy to ignore in small quantities (says the writer looking at her desk), across vast reaches of space this substance plays an important role. Stick enough grains together, the theory goes, and you’ll start to form rocks and eventually planets. On a galaxy-size scale, dust may even effect how the galaxy evolves.

A new survey of 323 galaxies reveals that dust is not only affected by the kinds of stars in the vicinity, but also what the galaxy is made of.

“These dust grains are believed to be fundamental ingredients for the formation of stars and planets, but until now very little was known about their abundance and physical properties in galaxies other than our own Milky Way,” stated lead author Luca Cortese, who is from the Swinburne University of Technology in Melbourne, Australia.

“The properties of grains vary from one galaxy to another – more than we originally expected,” he added. “As dust is heated by starlight, we knew that the frequencies at which grains emit should be related to a galaxy’s star formation activity. However, our results show that galaxies’ chemical history plays an equally important role.”

Galaxies in the Herschel Reference Survey in infrared/submillimeter wavelengths (with the Herschel space telescope, at left) and the Sloan Digital Sky Survey (right). Herschel's false-color image shows galaxies with cold dust (blue) and warm dust (red). Sloan highlights young stars (blue) and old stars (red). "Together, the observations plot young, dust-rich spiral/irregular galaxies in the top left, with giant dust-poor elliptical galaxies in the bottom right," the European Space Agency stated. Credit: ESA/Herschel/HRS-SAG2 and HeViCS Key Programmes/Sloan Digital Sky Survey/ L. Cortese (Swinburne University)
Galaxies in the Herschel Reference Survey in infrared/submillimeter wavelengths (with the Herschel space telescope, at left) and the Sloan Digital Sky Survey (right). Herschel’s false-color image shows galaxies with cold dust (blue) and warm dust (red). Sloan highlights young stars (blue) and old stars (red). “Together, the observations plot young, dust-rich spiral/irregular galaxies in the top left, with giant dust-poor elliptical galaxies in the bottom right,” the European Space Agency stated. Credit: ESA/Herschel/HRS-SAG2 and HeViCS Key Programmes/Sloan Digital Sky Survey/ L. Cortese (Swinburne University)

Data was captured with two cameras on the just-retired Herschel space telescope: Spectral and Photometric Imaging Receiver (SPIRE) and Photodetecting Array Camera and Spectrometer (PACS). These instruments examined different frequencies of dust emission, which shows what the grains are made of. You can see a few of those galaxies in the image above.

“The dust-rich galaxies are typically spiral or irregular, whereas the dust-poor ones are usually elliptical,” the European Space Agency stated. “Dust is gently heated across a range of temperatures by the combined light of all of the stars in each galaxy, with the warmest dust being concentrated in regions where stars are being born.”

Astronomers initially expected that a galaxy with speedy star formation would display more massive and warmer stars in it, corresponding to warmer dust in the galaxy emitting light in short wavelengths.

“However, the data show greater variations than expected from one galaxy to another based on their star formation rates alone, implying that other properties, such as its chemical enrichment, also play an important role,” ESA said.

You can read more about the research in the Monthly Notices of the Royal Astronomical Society or in preprint version on Arxiv.

Sources: Royal Astronomical Society and European Space Agency