Celestia Forums

Well +/- some tens of a percent, we are only seeing 0.45% of all planets within the green zone or close, so for each planet spotted there is likely 215 more that were not observed because the alignment of the orbital plane. And if we assume all the Kepler stars are the same mass as the Sun, after 4...

I wonder if my ...linear?... system actually fixes some of the problems with theirs? Their system is based on three assumptions I don't agree with: 1.) That all G2V stars are absolutely identical, 2.) That any differences are due to reddening, 3.) they don't allow any negative corrections. Your lin...

The result is only as good as the sum of the data entered. Or to put it another way, while the approach you describe is fast, it is also fast enough to where things can and do get missed. Fair enough, but there's also something to be said for the consistency of an automated solution. The Tycho-2 sp...

As to what I'm using...would you believe a somewhat elderly (?) MS Database Works? ::watches Starguy run screaming off into the night:: AAAAAaaaaaaaah Seriously, a relatively simple script will be able to process everything you need very quickly, seeing as you only need to do the same few operation...

But if say B-V stays put or even moves the 'wrong' way, the 'loaded dice' effect is still in place for the other two, which is often all it takes. Some caution needs to be taken with this: it is possible (but not 100% reliable) to distinguish between giants and dwarfs using photometric colors. Basi...

I have a suspicion this bears little resemblance to any other photo spectroscopic distance scheme you have seen. However, it did well enough in the callibrations - and so far its matched up reasonably well with what few alternative distances I've found for the stars in the ASCC. I admit it isn't......

Practically ALL professional astronomical software packages are linked to SIMBAD for data retrieval or identification purposes. If some inherent incorrectness turns out to be sufficiently severe, it surely will be corrected soon or later by the global research community. I hope I have succeeded to ...

If there was indeed a serious clash of Gould / Flamsteed numbers it would have long been eliminated from SIMBAD Well, SIMBAD is not always 'correct' in a pedantic sense... I can cite a few specific problems with it: 1.) GJ numbers greater than 3000 are not real and were invented by CDS (and astrono...

The only (slight) problem with this scheme is that SIMBAD does not differentiate between Flamsteed and Gould numbers. Your example, 82 G Eri, is in SIMBAD as 82 Eri, and searching for 82 G. Eri returns an error. http://simbad.u-strasbg.fr/simbad/sim-id?Ident=82+Eri&NbIdent=1&Radius=2&Rad...

What you called a systematic error is actually the usual statistical error, with the distance taken as a stochastic variable that is distributed according to a normal distribution (Gauss). Ah... And I thought 'systematic' was the error inherent in the system; here, that the distances can never be m...

I went out of my way to select stars where the values for the B, V, J, H, and K magnitudes were all under 0.1 That's probably a wise and defensible position... As you'll see below, trying to include errors on the magnitudes makes the problem MUCH more difficult, and in any case, Henry 2004 did not ...

Does that constitute calculating 'standard deviation''? Not quite, although it's on the right lines. You're right on the basic idea that you don't want negative numbers, but scientists like to force the issue; the two ways to force a number to be positive are to square it, or take the absolute valu...

Oh, and obviously, comparing YPC parallaxes work too, if you've got them. There's a wide range of accuracy in the YPC, but they were compiling 160 years of parallaxes. I also think your assumption that G0 stars won't turn out to be G5V stars is reasonable, and your tests that change the spectral typ...

I think we can make a rough crack at estimating your individual and systematic errors... It can be done based on your results or by error propagation, and because my statistics are not strong I prefer the after-the-fact results method. Besides, if we compare results, we don't have to track down and ...

Sounds like a monumental undertaking... I know you aren't asking for help with the project, but I think a Reduced Proper Motion diagram will help with the superluminous stars. (my apologies if you've already thought of this) Basically, it's an HR diagram where the 'absolute magnitude' is a 'reduced ...

I've been lurking around long enough to notice that Celestia (via nearstars.ssc) uses the RECONS 100 closest stars list for some of its nearby star information. Well, an updated version has recently been released/posted: http://www.chara.gsu.edu/RECONS/TOP100.posted.htm The biggest change in this up...