200+ Binary Orbits for Download & Testing, RESUMED!

[Evil Dr Ganymede]

You have some high mass and high luminosity G, F, and M stars - I presume those are Giants?

And how the heck do you get a G star that's 0.3 solar masses??

[t00fri]

You have some high mass
and high luminosity G, F, and M stars - I presume those
are Giants?

And how the heck do you get a G star that's 0.3 solar
masses??

These "Giants" are indeed interesting.

I checked "by hand" against the Hipparcos and the
S?derhjelm (1999) catalogs; these strange stars are
really there. So no bugs from my side.

This is the amazing 0.28 m_sol guy of class G taken from
Celestia's stars.txt (Hipparcos)


HIP84123 257.96906 -1.8509719 35.230827 11.4492 G

Go and look at it in Celestia:

[Celestia says T=5570 so clearly G, Lumi =0.0014*sun= tiny ]

This is a K0Ib giant (the red dot at high mass and lumi in my plot)

HIP54061 165.93265 61.751118 123.64178 1.80859 K0Ib

Bye Fridger

[Dollan]

In the case of HIP 84123 (aka Gliese 660), I think it may be a bug with Celestia's end. It is a double system, but the *combined* spectrum is being listed as M3.5 V with a combined visual luminosity of 0.0029.

...John...

[t00fri]

In the case of HIP 84123 (aka Gliese
660), I think it may be a bug with Celestia's end. It is a
double system, but the *combined* spectrum is being
listed as M3.5 V with a combined visual luminosity of
0.0029.

...John...

John,

thanks a lot. That makes much more sense. So then here
is another wrong entry in stars.txt for Grant to hunt
down .

I actually thought that stars.txt has been extensively
debugged...(the origial HIP catalog is supposed to
contain even more errors). Otherwise it would be easy
for me to extract the color class directly from the
original HIP catalog.

Unfortunately, the HIP color class that would refer to the
combined system is all we have got. Presumably, it's
even better to return to a plot of the combined
luminosities versus the "Keplerian" mass (m1+m2)...

Bye Fridger

[Dollan]

Odds are there will be a *lot* of these minor little bugs in there. We have a couple of centuries at least of different catalogues of the same stars, made by different people iwth different observational skills... Oi!

Still, glad to help. I haven't implimented your binary file yet, though. I'm waiting to see reviews on its functionality and such; heck, I'm still trying to get all of the add-ons I've made to conform with the newest Celestia version!

Can't wait to try it, though!

...John...

[Evil Dr Ganymede]

I checked "by hand" against the Hipparcos and the
S?derhjelm (1999) catalogs; these strange stars are
really there. So no bugs from my side.

The Giants aren't really "strange", unless they're listed as main sequence stars.

This is the amazing 0.28 m_sol guy of class G taken from
Celestia's stars.txt (Hipparcos)


HIP84123 257.96906 -1.8509719 35.230827 11.4492 G

I strongly suspect the data for that star is wrong then. You simply cannot get a G star that dim. They must have incorrectly measured the luminosity or spectral type or something else.

ARICNS says it's an M3 V, which sounds much more likely.
http://www.ari.uni-heidelberg.de/aricns ... c01372.htm

EDIT: Oops, Dollan beat me to it.

[t00fri]

Incidentally, I have checked that the incorrect spectral class of HIP 84123 above (G instead of M3.5V ) is already present in the /original/ Hipparcos catalog. So stars.txt (Celestia) did not introduce an extra bug here.

Bye Fridger

PS:

Wow, it's still kind of a special experience for me to be able now, to download the 103 MByte of the (packed) Tycho catalog in only 4:30 minutes!

[symaski62]

HIP 84123

"SpType G Spectral type (H76) "

[t00fri]

HIP 84123

"SpType G Spectral type (H76) "

Pardon symaski62, mais ca je ne comprends pas. Tu peux bien ecrire en francais si tu veux. Une fois (il y a tres longtemps) j'avais meme un passport francais...

The link you quoted just confirms that the original HIP catalog specifies SpType = G for HIP84123 as I wrote above. So what's the new aspect?

Bye Fridger

[Evil Dr Ganymede]

Fridger, are you sure the spectral types are correct in your file?

I was looking at 26 Draconis, and you claim it's:

Code: Select all

86036 "26 Dra A" # component A
{
OrbitBarycenter "26 Dra"
SpectralType "G0V"
AppMag  5.40

        EllipticalOrbit {
                Period              76.100
                SemiMajorAxis        8.081 # mass ratio 1.07 : 0.64
                Eccentricity         0.180
                Inclination         71.518
                AscendingNode      112.479
                ArgOfPericenter    -49.842
                MeanAnomaly        250.723
        }
}

"26 Dra B" # component B
{
OrbitBarycenter "26 Dra"
SpectralType "G2V"
AppMag 8.76

        EllipticalOrbit {
                Period              76.100
                SemiMajorAxis       13.468 # mass ratio 1.07 : 0.64
                Eccentricity         0.180
                Inclination         71.518
                AscendingNode      112.479
                ArgOfPericenter    130.158
                MeanAnomaly        250.723
        }
}


However, I've found references online to it being a G0V with a K3V companion and a distant M1V companion.
(see the NStars database)

Which is correct?

[symaski62]