Celestia Forums

Finally, a "planet" has been found orbiting a first magnitude star. I read the news here:
http://skytonight.com/news/home/3750872.html
Note the uncompromising title, avoiding the use of the term "planet"...

The forthcomming paper in A&A (http://dx.doi.org/10.1051/0004-6361:20065445) has an acceptance date in june, but I don't remember it mentioned here.

Orbital elements:

Period [days] 589.64 ?± 0.81
Tperiastron [JD] 2447739.02 ?± 4.5
K [m s^??’1] 41.0 ?± 1.6
e 0.02 ?± 0.03
?‰ [deg] 354.58 ?± 95.65
f(m) [solar masses] (4.21 ?± 0.48 ) ?—10^??’9
m sin i [MJupiter] 2.30?± 0.45
a [AU] 1.64 ?± 0.27
rms [ms^??’1] 20.6 (17.1)


Guillermo

Pollux b has been available in extrasolar.ssc on the CVS tree since January (file version 1.66), although I logged it as "HD 62509 b", so maybe no-one noticed ...
Download it here: http://celestia.cvs.sourceforge.net/celestia/celestia/data/extrasolar.ssc

Grant

Oh, I see, Grant, thanks! Somehow, I guessed this was known news to some (acceptance in june, must have been in the arXiv at least since then...). I just happened to read it today at the Sky and Telescope website...

Guillermo

Yeah, I remember reading about this a while back too. Oddly enough the date on the article is today, so I guess the folks at S&T were a bit slow on the uptake?

Still, it's cool. A gas giant orbiting a red giant, now that would make for some good space art!

Malenfant wrote:Still, it's cool. A gas giant orbiting a red giant, now that would make for some good space art!

I wonder if a star like Pollux would appear spherical - I've seen models of Betelgeuse which suggest it's really distorted with huge convection cells all over the place, but would this be noticeable on a K-giant like Pollux?

chaos syndrome wrote:

Malenfant wrote:Still, it's cool. A gas giant orbiting a red giant, now that would make for some good space art!

I wonder if a star like Pollux would appear spherical - I've seen models of Betelgeuse which suggest it's really distorted with huge convection cells all over the place, but would this be noticeable on a K-giant like Pollux?

Probably not... I think Pollux is in its Horizontal Branch (helium burning) phase which is fairly stable, whereas Betelgeuse is a more massive and much larger supergiant in its AGB phase, which is more unstable.

Malenfant wrote:

chaos syndrome wrote:

Malenfant wrote:Still, it's cool. A gas giant orbiting a red giant, now that would make for some good space art!

I wonder if a star like Pollux would appear spherical - I've seen models of Betelgeuse which suggest it's really distorted with huge convection cells all over the place, but would this be noticeable on a K-giant like Pollux?

Probably not... I think Pollux is in its Horizontal Branch (helium burning) phase which is fairly stable, whereas Betelgeuse is a more massive and much larger supergiant in its AGB phase, which is more unstable.

hey, I'd love to know more about this and to see such distortion in Celestia... any good links on the topic?

As usual, our receptors would be maxed out by either star and they would appear as white.

buggs_moran wrote:As usual, our receptors would be maxed out by either star and they would appear as white.

...and we'd instantly blinded by their light if we were anywhere near them. Betelgeuse is about 60,000 times brighter than the sun, that's surely got to be enough to sear our eyes out if we even glanced in its general direction, assuming we're within a 5-10 AU of the surface anyway?

I wonder if we'd find the light light reflected off objects (eg a planet, the ground etc) blinding too?

I guess I'm assuming you have some of the space-art-standard ultra-high-quality polaroid sunglasses about your person when looking in the "towards the star" kind of direction.

ElChristou wrote:8O hey, I'd love to know more about this and to see such distortion in Celestia... any good links on the topic?

Have a look at this page, it includes simulations of solar granulation, granulation on metal-poor stars, and a model of Betelgeuse. There are movies too.

Malenfant wrote:

buggs_moran wrote:As usual, our receptors would be maxed out by either star and they would appear as white.

...and we'd instantly blinded by their light if we were anywhere near them. Betelgeuse is about 60,000 times brighter than the sun, that's surely got to be enough to sear our eyes out if we even glanced in its general direction, assuming we're within a 5-10 AU of the surface anyway?

I wonder if we'd find the light light reflected off objects (eg a planet, the ground etc) blinding too?

Betelgeuse's radius is about 650 times Sol's, so its surface area is 420,000 times as great. Per unit area, Betelgeuse releases about a seventh as much radiation as Sol, on average. If that radiation is fairly uniform, Betelgeuse might actually be easier on the eyes than Sol.

Pollux's radiation density is about half that of Sol.

MackTuesday wrote:Betelgeuse's radius is about 650 times Sol's, so its surface area is 420,000 times as great. Per unit area, Betelgeuse releases about a seventh as much radiation as Sol, on average. If that radiation is fairly uniform, Betelgeuse might actually be easier on the eyes than Sol.

Pollux's radiation density is about half that of Sol.

Hm, maybe I was thinking more of the B V stars or something there then (which aren't THAT much bigger than Sol and a hell of a lot brighter).