Posts by granthutchison

by granthutchison
10.03.2009, 19:40
Forum: Development
Topic: Binary Orbits Revisited!
Replies: 106
Views: 29779

Re: Binary Orbits Revisited!

That sounds indeed like a workable solution, provided you choose the identical distances from Andrew's revised stars for the barycenters. So far the filtering was rather attached to names that often didn't match. That was indeed tedious. This way the burden goes mainly to you, since YOU will have t...
by granthutchison
10.03.2009, 17:39
Forum: Development
Topic: Binary Orbits Revisited!
Replies: 106
Views: 29779

Re: Binary Orbits Revisited!

what I don't see in your arguments is this: suppose I have set up the binaries according to my favoured database categories (astrometric, visual, spectroscopic, eclipsing,...), along with a separate multistar (>2) data file, say. Suppose as a subset of this much larger AND expandable data base ALL ...
by granthutchison
10.03.2009, 13:41
Forum: Development
Topic: Binary Orbits Revisited!
Replies: 106
Views: 29779

Re: Binary Orbits Revisited!

I just feel that your selection criterion of distance (< 25 ly) tends to block quite thoroughly other sensible, systematic classifications, in particular, the classification by method of observation (astrometric, visual, spectroscopic, eclipsing,... systems). Of course, the cataloguing of specifica...
by granthutchison
10.03.2009, 00:46
Forum: Development
Topic: Binary Orbits Revisited!
Replies: 106
Views: 29779

Re: Binary Orbits Revisited!

But then your multiple star orbits must be on a pretty shaky ground, since I would not know any reliable source for mass ratios except for spectroscopic data in some cases ?? Also all nearby visuals from the 6th catalogue which are not in Soedehjelm get their orbit shapes from the uncertain mass-lu...
by granthutchison
10.03.2009, 00:04
Forum: Development
Topic: Binary Orbits Revisited!
Replies: 106
Views: 29779

Re: Binary Orbits Revisited!

Sorry, please help me, I am feeling a bit stupid now: As far as I could make out, for visual binaries, you are only refering to the "Sixth Catalog of Orbits of Visual Binary Stars (http://ad.usno.navy.mil/wds/orb6.html)" in the nearstars header (besides RECONS). The sixth catalog is by Wi...
by granthutchison
09.03.2009, 22:27
Forum: Development
Topic: Binary Orbits Revisited!
Replies: 106
Views: 29779

Re: Binary Orbits Revisited!

But is every entry beginning "L ..." part of the Luyten catalog? Is every "G ..." a Giclas? Oh, sorry, I've got that backwards. You'd be storing the "L " and "G " forms, and the user would have the option of typing "Luyten "or "Giclas ". S...
by granthutchison
09.03.2009, 22:04
Forum: Development
Topic: Binary Orbits Revisited!
Replies: 106
Views: 29779

Re: Binary Orbits Revisited!

I agree that making the parser smarter is a sensible way to handle the conflict. It probably makes sense to store the names in the standardized format recognized by SIMBAD, display the familiar names, and accept either as user input. That's exactly what I had in mind. :) The next question would be ...
by granthutchison
09.03.2009, 21:49
Forum: Development
Topic: Binary Orbits Revisited!
Replies: 106
Views: 29779

Re: Binary Orbits Revisited!

The primary/secondary mass ratios are among the most crucial parameters for the (elliptical) orbit geometry, I guess you agree ;-) . These are gotten, however, in RECONS via a quantitatively most dubious mass-luminosity relation, using the absolute magnitude values from the Gliese catalog as an inp...
by granthutchison
09.03.2009, 20:07
Forum: Development
Topic: Binary Orbits Revisited!
Replies: 106
Views: 29779

Re: Binary Orbits Revisited!

The primary/secondary mass ratios are among the most crucial parameters for the (elliptical) orbit geometry, I guess you agree ;-) . These are gotten, however, in RECONS via a quantitatively most dubious mass-luminosity relation, using the absolute magnitude values from the Gliese catalog as an inp...
by granthutchison
09.03.2009, 17:34
Forum: Development
Topic: Binary Orbits Revisited!
Replies: 106
Views: 29779

Re: Binary Orbits Revisited!

Fridger: My apologies if I reported problems that don't exist in the final version of these files. There are extensive commented sections in the versions I downloaded from the links in your first post, so I assumed that the work of "commenting out" had already been done. RECONS contains no...
by granthutchison
08.03.2009, 22:12
Forum: Development
Topic: Binary Orbits Revisited!
Replies: 106
Views: 29779

Re: Binary Orbits Revisited!

Fridger: Since you started this thread requesting testing of your files, I have a couple of bug reports: 1) The binary Hip 73182 is present in both visualbins.stc and spectbins.stc , under different names: "HIP 73182" and "Gl 570B". This produces four stars around the same baryce...
by granthutchison
03.03.2009, 23:22
Forum: Physics and Astronomy
Topic: G ring Arc moon found at Saturn
Replies: 4
Views: 2431

Re: G ring Arc moon found at Saturn

I've added this to poormoons.ssc as "2008 S 1". poormoons.zip I'll PM granthutchison to update the official copy (as poormoons.ssc is his baby :) ). I sent Selden my own version based on the contents of IAUC #9023, about forty minutes ago as I type this. So it'll appear in due course. Grant
by granthutchison
27.02.2009, 19:08
Forum: Physics and Astronomy
Topic: HD 80606b is a transiting planet
Replies: 4
Views: 2380

Re: Weather on HD 80606b

ajtribick wrote:This is huge.

PRIMARY TRANSIT.
I've just committed an update to extrasolar.ssc, so now you can watch the transit of Feb 13-14 in Celestia.

The new file is here: http://celestia.svn.sourceforge.net/viewvc/celestia/trunk/celestia/data/extrasolar.ssc?view=log

Grant
by granthutchison
19.02.2009, 16:31
Forum: Development
Topic: Nine New Ring Gap Names
Replies: 3
Views: 2283

Re: Nine New Ring Gap Names

Selden looking at the various planetary ring systems the least developed is Jupiter's, depending on which textures one look's at 2 that I'm aware putting the names to them doesn't really match. Saturn's new names are ok but fitting them so they are viewable is not easy, possible solution would perh...
by granthutchison
15.02.2009, 17:23
Forum: Development
Topic: Binary Orbits Revisited!
Replies: 106
Views: 29779

Re: Binary Orbits Revisited!

If I remember correctly, it's been a couple of years since the issue of nearstars.stc last came up on this forum. At that time I posted a clear statement to the effect that I did not consider the file to be "my" property, and that I was quite happy for Fridger, Andrew, Chris, or anyone els...
by granthutchison
28.01.2009, 17:57
Forum: Bugs
Topic: Positions of Phobos and Deimos
Replies: 72
Views: 19526

Re: Positions of Phobos and Deimos

Slightly delayed notice that I've now committed the above revision. Mainly small changes to trailing decimals, for the sake of consistency. The major change is the reversion of Venus to UniformRotation: I've checked the result against JPL Horizons' predicted sub-observer latitude & longitude for...
by granthutchison
20.01.2009, 00:14
Forum: Bugs
Topic: Positions of Phobos and Deimos
Replies: 72
Views: 19526

Re: Positions of Phobos and Deimos

Since there's no precession listed for Venus, it might make the most sense to stick with the UniformRotation. OK. If I don't see any objections, I'll restore the UniformRotation for Venus and restore the old "cosmetic" rotation parameters for Prometheus and Pandora (matching the meridian ...
by granthutchison
19.01.2009, 23:48
Forum: Bugs
Topic: Positions of Phobos and Deimos
Replies: 72
Views: 19526

Re: Positions of Phobos and Deimos

Using the flipped flag fixes the gross errors, but still leaves about a tenth of a degree discrepancy with the current UniformRotation for Venus. Did you start with the IAU elements from http://astrogeology.usgs.gov/Projects/WGCCRE/constants/iau2000_table1.html ? I used the figures from the last Ex...
by granthutchison
19.01.2009, 01:20
Forum: Bugs
Topic: Positions of Phobos and Deimos
Replies: 72
Views: 19526

Re: Positions of Phobos and Deimos

There's also a slight incongruity in having a CustomRotation for bodies with such as Enceladus and Dione, for which the USGS/IAU parameters merely describe a uniform rotation. The commented-out UniformRotation does exactly the same job as the CustomRotation for these bodies, but more transparently. ...
by granthutchison
18.01.2009, 22:54
Forum: Bugs
Topic: Positions of Phobos and Deimos
Replies: 72
Views: 19526

Re: Positions of Phobos and Deimos

I can't resolve the rotation parameters for Prometheus with its orbital elements: the prime meridian seems to be offset compared to the HORIZONS elements at epoch. Setting the orbital and rotation periods equal merely preserves the offset (although HORIZONS does now provide a mean orbital period of ...

Go to advanced search