Posts by Fafers_br

by Fafers_br
02.10.2020, 02:41
Forum: Add-on releases
Topic: Updated stars.dat including Gaia DR2 data (update 2020-11-30)
Replies: 70
Views: 11033

Re: Updated stars.dat including Gaia DR2 data (update 2020-11-30)

ajtribick wrote:I am sitting here going "mwahahaahaaa I am going to set a bunch of stars to O-type to mess with Fafers-br."
I appreciate your sense of humor as much as I appreciate your efforts in making this addon. Thank you for both. :razz:
by Fafers_br
30.09.2020, 21:48
Forum: Add-on releases
Topic: Updated stars.dat including Gaia DR2 data (update 2020-11-30)
Replies: 70
Views: 11033

Re: Updated stars.dat including Gaia DR2 data (update 2020-11-30)

Hi ajtribick. After installing the v1.0.1, I noticed very suspicious "blue stellar patches" in the Galaxy when setting the magnitude limit to 15.2. To my surprise, I determined that this new version created a large number of stars with spectral type "O". Was this intentional like...
by Fafers_br
08.07.2020, 18:48
Forum: Celestia Users
Topic: Pictures from Celestia
Replies: 584
Views: 110248

Re: Pictures from Celestia

Wow! Very clever.
by Fafers_br
22.04.2020, 01:51
Forum: Add-on development
Topic: Request: Predicted orbits of Neptune by Adams and Le Verrier
Replies: 2
Views: 611

Re: Request: Predicted orbits of Neptune by Adams and Le Verrier

Hi Joey.
I found this one. Hope it helps.

And here is an interesting reading about Neptune's discovery, from where I took the link above.

I couldn't find inclination and ascending nodes data. I used Neptune's ones to achieve the orbits below.

Bye.
by Fafers_br
21.04.2020, 18:06
Forum: Add-on releases
Topic: LMC update
Replies: 7
Views: 1179

Re: LMC update

Great job LukeCel. :clap:
And thanks for the kind citation.
by Fafers_br
07.04.2020, 02:35
Forum: Add-on development
Topic: Distance to the Tarantula Nebula
Replies: 5
Views: 871

Re: Distance to the Tarantula Nebula

I found two papers on the structure of the LMC. The one I found most "didatic" was Koerwer 2009 . It provides a good 3D schematics in figure 6. The other is Subramanian 2013 . Both seem to agree that 30 Dor is slightly behind the plane of the disc of LMC. Refer to section 5 from first sour...
by Fafers_br
24.03.2020, 16:57
Forum: Development
Topic: Visual Extinction in Celestia?
Replies: 5
Views: 1313

Re: Visual Extinction in Celestia?

As an exercise of pure imagination, if we could abandon the scientific rigour for a while... We could fix the value of Rv=3.1. Then, for the same Schulte 16 given as example above. From Earth: d'=d=1514.6pc The declared value for Av would be 4.5. Then: Avpc=Av/d'=0.02971mag/pc. So: E(B-V)=d'*Avpc/Rv...
by Fafers_br
24.03.2020, 04:24
Forum: Development
Topic: Visual Extinction in Celestia?
Replies: 5
Views: 1313

Re: Visual Extinction in Celestia?

Have you thought of a good way to add interstellar reddening as well? As we know, stars appear not just dimmer, but redder when obscured by dust because the dust preferentially scatters blue light. I think reddening is more complicated. Well, even my suggestion for extinction is already naively con...
by Fafers_br
24.03.2020, 02:41
Forum: Development
Topic: Visual Extinction in Celestia?
Replies: 5
Views: 1313

Visual Extinction in Celestia?

Hello there! As everybody knows, Celestia does not take visual extinction (Av) in consideration in its calculations. This has some consequences, and one of them is the underestimation of the AbsMag and, hence, the calculation of the stars' radius when using the black body aproximation. I'd like to p...
by Fafers_br
08.03.2020, 14:56
Forum: Add-on development
Topic: Poll: Exoplanet Catalogue planet ordering
Replies: 14
Views: 1789

Re: Poll: Exoplanet Catalogue planet ordering

The tree displayed in the solar system browser, with the star on the top and the planets below, also gives the "feeling" of increasing distance from the star as you go down the planet list. So, it's one more reason in favor of the distance order. As long as the order of discovery date is r...
by Fafers_br
19.02.2020, 20:59
Forum: Add-on releases
Topic: Updated stars.dat including Gaia DR2 data (update 2020-11-30)
Replies: 70
Views: 11033

Re: Updated stars.dat including Gaia DR2 data (update 2020-11-30)

It is a great work indeed, ajtribick.
Congratulations and thank you for that!
by Fafers_br
17.12.2019, 15:16
Forum: Help Central
Topic: Inclination for a barycenter ?
Replies: 6
Views: 1063

Re: Inclination for a barycenter ?

Hi Jujuapapa! Try this: Barycenter "Star_A" { RA 180.0000 Dec 20.0000 Distance 200.0 #Inclination -20.0000 } # # Star B # "Star B" { OrbitBarycenter "Star_A" SpectralType "G1V" AbsMag 4.67 EllipticalOrbit { Period 1000 SemiMajorAxis 100 Eccentricity 0.01 Incli...
by Fafers_br
16.12.2019, 16:36
Forum: Help Central
Topic: Inclination for a barycenter ?
Replies: 6
Views: 1063

Re: Inclination for a barycenter ?

Hi Jujuapapa. This is strange. In my Celestia the code I sent resulted in the figure bellow when viewing from the Sun: celestia_Inclination for a barycenter.jpg The orbits are aligned and it's an eclipsing system. Of course, you'd have to change the orbital parameters of the rest of the system to ma...
by Fafers_br
15.12.2019, 15:52
Forum: Help Central
Topic: Inclination for a barycenter ?
Replies: 6
Views: 1063

Re: Inclination for a barycenter ?

Hi jujuapapa. I think what you want is basically a system inclined 90º relative to the plane-of-sky. I recommend you use Grant Hutchison's starorbs spreadsheet for Celestia. Here's the code using your data in Grant Hutchison's spreadsheet, supposing that the AscendingNode you provided is relative to...
by Fafers_br
11.12.2019, 01:47
Forum: Development
Topic: Proposed cool stars temperatures update
Replies: 8
Views: 1453

Re: Proposed cool stars temperatures update

No objections. I see you are propposing the temperatures from E. Mamajek's table. I think it's a good source.
by Fafers_br
08.11.2019, 03:13
Forum: Add-on releases
Topic: Extrasolar Planets (updated catalogue)
Replies: 92
Views: 75369

Re: Extrasolar Planets (updated catalogue)

If I can find some rotation rate relations for planet's mass vs age, that's what I'd like to do. I've considered just extrapolating downward from the brown dwarf regime -- something that should be somewhat well characterized, but I haven't managed to find some decent research on it since I haven't ...
by Fafers_br
31.08.2019, 01:11
Forum: Add-on releases
Topic: Object Comparison
Replies: 20
Views: 7478

Re: Object Comparison

The issue arises in the way Celestia calculates the "distance." For a planet, the distance is between the observer and the surface, whereas for a star, it is defined with respect to the centre of the star. If you "land" on the star's surface, you'll note you will have quite some...
by Fafers_br
29.08.2019, 20:56
Forum: Add-on releases
Topic: Object Comparison
Replies: 20
Views: 7478

Re: Object Comparison

Talking about object comparison, and apologizing for drifting a little offtopic, this topic reminded me of an issue I observed in my Celestia 1.6.0 (Yes, I know...). Once upon a time, in a not so far away galaxy, I had the idea of making a comparison of object sizes putting them side by side in a ve...
by Fafers_br
24.08.2019, 19:55
Forum: Celestia Users
Topic: Celestia Location Distribution
Replies: 13
Views: 4565

Re: Celestia Location Distribution

City included in my profile. :wink:
by Fafers_br
12.08.2019, 21:36
Forum: Bugs
Topic: Circumbinary Planet Issues
Replies: 8
Views: 4218

Re: Circumbinary Planet Issues

(...)the barycenters do not show up in the Stars List when set to "planets with stars." Apparently it was the developers' choice not to show barycenters in the Star Browser (if you mark the option "nearest", they will not show up too). But their planetary companions are correctl...

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