Celestia Forums

I wouldn't say it was unlikely either. All you have to do to minimize the perturbations you're talking about is get the outer component far enough away. And if there were dust rings around close binaries, surely there could be planets formed from such dust. And: there are plenty of binary stars with...

[EDIT: Selden explained the HR diagram much better than I did] I don't know what's going on with your three branches of K/M stars, but a K9V star should be somewhere around 0.6 solar radii (and 0.6 solar masses). As a generic rule of thumb, for M stars, Mass (in solar units) should roughly equal Rad...

I'm surprised this discussion has gone this far without any mention of mass functions (intial or current). Basically, to achieve a realistic representation of stars, you need the H-R diagram for the properties of stars, AND a mass function to relate the number of stars at each bin- very many M, very...

What the above posters said. An M0IV class star would imply a former K star in the process of leaving the main sequence; the universe is too young for any main sequence K stars to have done that yet. G stars are sufficiently short-lived, but they will turn into G or K subgiants, and K or M giants. Y...

http://appropriations.house.gov/News/DocumentSingle.aspx?DocumentID=250023 (scroll down for the highlights in regards to NASA) National Aeronautics and Space Administration (NASA) – NASA is funded at $16.8 billion in the bill, which is $1.6 billion below last year’s level and $1.9 billion below the ...

...and I realized nearstars.ssc goes out to 25 LIGHT YEARS... There isn't quite as much in the RECONS file that would help you there.

Over the past few weeks, I've attempted to determine just how accurate the ThinkerX ASCC distances are, and I've reached some tentative conclusions (although ThinkerX privately told me he can't quite replicate my results... we're not entirely sure why. I will attempt to highlight where I think the p...

Two thoughts: 1.) Isn't QT4 cross-platform? One could then use the QT4 version on Mac OS, Windows and Linux. Or have I overestimated how much of Celestia is written in QT4? 2.) [quote=toofri"]A 1.6.1 release would admittedly update the astronomical database of Celestia 1.6.0, but it would come ...

Actually, I'll come up with a better file for you, with the 1.5m results and one weighted mean per system.

You may also be interested in this file (I apologize for not pointing it out before you before you updated nearstars.stc http://www.chara.gsu.edu/RECONS/publishedpi That file contains every parallax RECONS has published thus far, from the CTIO 0.9m program. Some warnings: ⋅ It's missing pa...

First and last measures almost always came from the WDS (interestingly enough there appear to be a few double stars out there *not* in the WDS). I'm not surprised... but the nice thing about WDS is that it's comprehensive enough you can be forgiven for ignoring stuff NOT in there... although it's b...

At this point, about 32,000 stars (the numbers really cratered in the far southern declinations for whatever reason). I suspect that's because you're using spectroscopy to determine the distances. Spectroscopy (and really, every kind of astronomy, although now we have all-sky surveys like Tycho) ha...

I always look for Alpha Cen, Castor/YY Gem, Epsilon Eri, Gl 644/643, 55 Cnc, and Regulus. Alpha Cen ABC 'cause it's the closest system, Epsilon Eridani 'cause it's the closest planetary system, Gl 644ABCD/643 because it's the busiest system in 10 pc/32.6 light years, Castor ABCD/YY GemAB because it'...

It's in Celestia, but not under that name. Look for HIP 89825 or HD 168442. Apparently no one linked it to the name "Gl 710" or "Gliese 710"...

Just some random notes: There are plenty of G2V stars in the galaxy. That 10-15 light year distance Hungry4info quoted isn't bad for G2V stars; (all the other types are much rarer). There are 2 G-type dwarf stars within 15 light years/5 parsecs of us: Alpha Centauri A (G2V) and Tau Ceti (G8V). I don...

So...do the folks at Simbad (who-ever they are) accept corrections of this sort? If so, how to go about getting hold of them? Most definitely yes. http://simbad.u-strasbg.fr/guide/ch02.htx The relevant quote: The data contained in SIMBAD are also permanently updated, as a result of errata, remarks ...

2MASS (as the name implies) is an all sky survey, focusing on the infrared colors. Ok...looking through the bigger catalogues at VizieR, I see that the 2MASS results are being attached to more and more of them - not just the ASCC, but the Carlsberg Meridian Catalogue, the USNO, and a couple of othe...

Hey ThinkerX, have you seen this?: http://www.aavso.org/apass Granted, this won't work with your dataset because there's no 2MASS crossmatch (or proper motions), but they've apparently got 8 million more stars (in B and V) to extend the Tycho database. As for your lack of F5, G0, and G5 stars... I h...

The rest seem evenly split between wide Common Proper Motion pairs (talking separations on the order of hundreds to thousands of astronomical units, possibly a light year or two in some instances) and close binaries, with orbital periods on the order of a couple decades to a couple centuries. Only ...

Gaia will have an accuracy of 20 µas at mag 15, and 200 µas at mag 20, measuring the parallaxes of some billion stars. Hipparcos had an accuracy of ~2000 µas for 100,000 stars. That was the expected accuracy; Hipparcos (even in its first reduction) managed to get closer to ~1000 µas for most stars ...