1RXS J160929.1-210524 b

Direct Imaging and Spectroscopy of a Planetary Mass Candidate Companion to a Young Solar Analog
http://arxiv.org/abs/0809.1424

Abstract wrote:

We present near-infrared imaging and spectroscopy of a planetary mass candidate companion to 1RXS J160929.1-210524, a roughly solar-mass member of the ~5 Myr-old Upper Scorpius association. The object, separated by 2.22" or 330 AU at ~150 pc, has infrared colors and spectra suggesting a spectral type of L4(-2/+1) and a temperature of 1800(-100/+200) K. The H- and K-band spectra provide clear evidence of low surface gravity, and thus youth. Based on the widely used DUSTY models, we infer a mass of 8(-1/+4) Mjup. If gravitationally bound, this would be the lowest mass companion imaged around a normal star thus far, and its existence at such a large separation would pose a serious challenge to theories of star and planet formation.

So if it is bounded, then with a mass of 8 Jupiters... we're going to call this one a planet, right?

Look--planet (perhaps) ^o^

The Extrasolar Planets Encyclopaedia is currently listing this one as "unconfirmed" because it is not yet known if these two objects genuinely form a common proper motion pair. Many of the derived properties of the object assume that is located at the same distance as the star, which is not yet certain.

Still, a giant planet at 300 AU? Or a sub-brown dwarf?

I'd probably be happier about calling this one a planet than I would about the companion of 2M1207 - the latter system has a mass ratio more typical of binary stars than planets.

P.S. 1RXS J160929.1-210524b is quite a hideous designation isn't it?

Quote :

P.S. 1RXS J160929.1-210524b is quite a hideous designation isn't it?

How about ... the "Scorpion King"?? ^____- lol

Lazarus wrote:

P.S. 1RXS J160929.1-210524b is quite a hideous designation isn't it?

SIMBAD also has a few other names for the star. Among the more pleasurable,
2MASS J16093030-2104589
GSC 06213-01358

The paper shortens it to 1RXSJ1609-2105, but that's not much better.

Going by the logic by which 2MASS J12073347-3932540 gets shortened to 2M1207, maybe 1R1609? Or 1RXS1609?

In all honesty, I'll just go with whatever everyone else calls it for general ease. Maybe bind F7 to write out "1RXS J160929.1-210524" or something

Much to my disgust, news agencies that are just now picking up on this are reporting it to be the first planet imaged. While I do think that the image of 1RXS J160929.1-210524 and its possible companion is much nicer than, say, the one of 2M1207, GQ Lup, UScoCTIO 108, and AB Pic, it's certainly not the first.

It is possible to make the argument that the companions to UScoCTIO 108, AB Pic and especially GQ Lup are brown dwarfs. 2M1207 seems to be on more solid ground, but the mass ratio is suspicious: is the companion a planet or a sub-brown dwarf (especially given that both objects appear to have separate circumstellar discs)? So the case that this is the first extrasolar planet imaged is not completely ridiculous, though it is a bit misleading not to mention at least 2M1207b.

Wow! It's something nice to stare at and wonder about for a while at the very least. This is another thing that can reignite my passion for exoplanets after not having thought about them much for half a year.

National Geographic called it a possible first planet imaged around a "sun-like" star.

http://news.nationalgeographic.com/news/2008/09/080915-planet-picture.html

Ohhh this is nice.

RXS J16 1-21 b is what I'd call it.

Hang on it says this thing is over 1800 degrees K. Is this a young syst5em or something?

Short hand will probably be, 1RXS J1609b or 1RXS 1609b.

Confirmation of of identical proper motion as the star.
http://arxiv.org/abs/1006.3070

Interesting coincidence. Yesterday I was thinking about this star and the confirmation of its companion.

Great thing, one more in the batch of imaged planets.