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largest known stars

Posted: 22.05.2018, 22:58
by Danny Lorraine
hey, i have had celestia since 2012 but i couldn't find the largest known stars . some of them even have wrong sizes .

betelgeuse - 600 solar radii (950 in reality)
antares - 730 solar radii (800 in reality)
theta muscae - not found
v382 carinae - not found
v838 monocerotis - not found
v509 cassiopeiae - not found
mu cephei - 3870 solar radii (1420 in reality)
ky cygni - not found
v354 cephei - not found
nml cygni - not found
vv cephei a - 370 solar radii (1900 in reality)
vv cephei b - not found
vy canis majoris - not found

is there any way to find these stars ? thanks.

Added after 49 seconds:
also, there is an addon that adds vy canis majoris, but its radius is short by 100 solar radii. is there any way to fix this ? thanks.

Posted: 23.05.2018, 02:36
by Danny Lorraine II
(i lost the password to my first account above so now i use this account)
edit: celestia only has stars that have hipparcos indentification numbers (like HIP ??????) all of those stars have HIP numbers, so why aren't they present? hmmm...

Posted: 23.05.2018, 10:51
by selden
You can specify a new radius of any star by providing an STC file in your extras folder which contains Modify statements.

If you were to provide this Addon, I'm sure it would make a lot of people very happy. However, such an Addon should specify the sources for the values you use. Some of the values you mention above do not seem to agree with recent estimates, for example, but it's hard to judge their validity without knowing where you got them. Whenever possible a radius should be taken from a published research paper or other authoritative source of astronomical values. Typos often happen in popularized articles.

In the brief example below, I didn't follow my own advice. It's a lot of work to find the best measurements, so I used a few of the values provided by NASA in a table of about 20 star sizes at ... star_dimensions_worksheet.html

I rounded them off because very high precision is hard to justify in most cases.

Code: Select all

# Stellar radii calculated from values provided at
Modify Star "Antares" { Radius 540000000 } # 776 x solar radius of 695,508 km
Modify Star "BET Lyr" { Radius 13400000 } # 19.2
Modify Star "Betelgeuse" { Radius 696000000 } # 1000

Posted: 23.05.2018, 19:22
by Danny Lorraine II
i think the source of antares being 800 solar radii was the 1990 lunar occultion, which gave estimates between 653 to 1,246 solar radii

Added after 17 minutes 51 seconds:
vv cephei a holds the worst error. it is known to have a diameter 1.900 times our sun's , but celestia has only 370 sr , and vv cephei b is not present . what is the source for those changes ?

Added after 1 hour 26 minutes:
here are i think the values of the largest known stars:

VY Canis Majoris: 2.200
vv cephei a : 1.900
nml cygni: 1.650
woh g64: 1.540
westerlund 1-26: 1.530/2.544
vx sagittarii: 1.520
v354 cephei: 1.520
kw sagittarii: 1.460
ky cygni: 1.420
mu cephei: 1.420
hr 5171: 1.315
rs persei: 1.000
betelgeuse: 950
v509 cassiopeiae: 910
theta muscae: maybe 800?
v838 monocerotis: 800
antares: 800
v382 carinae: 747
119 tauri: 608
r lepus: 500

Posted: 24.05.2018, 10:47
by selden

As I mentioned previously, you need to say where you got the radius values that you're mentioning. Some might be more reliable than others.

Posted: 24.05.2018, 13:43
by Gurren Lagann
I agree with selden here. Danny is using sources from 2008-2012.

Posted: 24.05.2018, 19:28
by Danny Lorraine II
@Gurren Lagann
no .

Added after 3 hours 39 minutes:
sources from up to 2005 are still reliable . 2.100 for VY Canis Majoris was calculated with brightness and temperature . so its still right .

Posted: 24.05.2018, 23:16
by Gurren Lagann
But not all of then are right, ok? You are just using inaccurate data.

Posted: 25.05.2018, 00:10
by Danny Lorraine II
@Gurren Lagann shut up!

Posted: 25.05.2018, 22:53
by Gurren Lagann
YOU SHUT UP! goes Super Saiyan Blue

Posted: 26.05.2018, 05:55
by Danny Lorraine II
you look like stupid head with your dick hairline making you look like you wear gucci ! now smell my feet or die !

Posted: 26.05.2018, 10:39
by Goofy
Hi Gurren Lagann and Danny Lorraine II.
Just an opinion.
I'm sincerely tired to read on many threads (why not only one?) questions regarding what is the bigger star and so on, or why xxx isn't in Celestia data.
Well all the questions have been replied many times (with even too much patience, IMHO), so why are you going on and on again on the same argument?
Moreover now, in two different threads you two switched from plain discussion to reciprocal offenses, and this is not the right way here in Celestia. :fie:
So I'm asking the moderator to please ban for some time both of you, hoping that some days without quarrelling can calm your astronomical impetuosity.
BTW I, and I think many other Celestia users, can sleep without problems even without having knowledge of VY CMa real diameter (as for angel's sex, BTW), so, please, stop!
Thanks a lot.
Goofy :smile:

Posted: 26.05.2018, 19:59
by Danny Lorraine II
okay we will stop . sorry for the inconvenience .

Posted: 26.05.2018, 20:41
by Gurren Lagann
Sorry goofy

Posted: 26.05.2018, 21:40
by Goofy
You are welcome!
Goofy :smile:

Posted: 27.05.2018, 21:00
by Danny Lorraine II
anyway i respect your opinions but in my belief i don';t believe uy scuti exists

Posted: 28.05.2018, 23:31
by Gurren Lagann
Everyone has their own opinions, why are we fighting over they?

Posted: 03.06.2018, 19:50
by Danny Lorraine II
anyway my addon is in the first stages of develeopment . however i don ' t approve of the bad texture wrapping . like in here :