A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Amateur Astronomy
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Multiple systems - How are they determined to be multiple?



 
 
Thread Tools Display Modes
  #1  
Old October 6th 03, 12:16 AM
Chris L Peterson
external usenet poster
 
Posts: n/a
Default Multiple systems - How are they determined to be multiple?

On Sun, 5 Oct 2003 17:22:37 -0600, "PrisNo6" wrote:

I am working with a series of wide association stars in Harrington's _Touring the Universe with Binoculars_. Mostly these are
stars he extracted from the old Aitken New General Catalogue of Double and Multiple Stars. It appears the current catalogue is
Dommanget's _Catalogue of the Components of Double and Multiple Stars (2002), CDS catalogue I/274.

How do professional astronomers determine whether a star is in a multiple system, let's say separated by 70-100 arcseconds? What
exactly is measured to support their conclusion that a star is in a multiple system and is not just an optical binary?


You can observe the separation and angle changing between the components, and
determine that they have a common center of rotation. Sometimes the line-of-site
speeds are measured spectroscopically, leading to the same information.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
  #2  
Old October 6th 03, 12:22 AM
PrisNo6
external usenet poster
 
Posts: n/a
Default Multiple systems - How are they determined to be multiple?

I am working with a series of wide association stars in Harrington's _Touring the Universe with Binoculars_. Mostly these are
stars he extracted from the old Aitken New General Catalogue of Double and Multiple Stars. It appears the current catalogue is
Dommanget's _Catalogue of the Components of Double and Multiple Stars (2002), CDS catalogue I/274.

How do professional astronomers determine whether a star is in a multiple system, let's say separated by 70-100 arcseconds? What
exactly is measured to support their conclusion that a star is in a multiple system and is not just an optical binary?



  #3  
Old October 6th 03, 01:02 AM
Morris Jones
external usenet poster
 
Posts: n/a
Default Multiple systems - How are they determined to be multiple?

PrisNo6 wrote:
How do professional astronomers determine whether a star is in a multiple system, let's say separated by 70-100 arcseconds? What
exactly is measured to support their conclusion that a star is in a multiple system and is not just an optical binary?


Similar distance by parallax, and the same proper motion is a good clue.
Then measure their relative motion to each other and look for an orbit.

But I'm just guessing.

Mojo
--
Morris Jones *
San Rafael, CA

http://www.whiteoaks.com
  #4  
Old October 6th 03, 06:47 AM
PrisNo6
external usenet poster
 
Posts: n/a
Default Multiple systems - How are they determined to be multiple?

Thanks Chris - a good, simple, clear explanation. Kurt

"Chris L Peterson" wrote in message ...
On Sun, 5 Oct 2003 17:22:37 -0600, "PrisNo6" wrote:

snip
How do professional astronomers determine whether a star is in a multiple
system, let's say separated by 70-100 arcseconds? snip


You can observe the separation and angle changing between the components,
and determine that they have a common center of rotation. Sometimes the line-of-
site speeds are measured spectroscopically, leading to the same information.




 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Planetary Systems With Habitable Earths? Rodney Kelp Policy 6 April 2nd 04 02:32 PM
NASA Releases Near-Earth Object Search Report Ron Baalke Astronomy Misc 0 September 10th 03 04:39 PM
Boeing-Led Team to Study Nuclear-Powered Space Systems Ron Baalke Technology 2 July 31st 03 06:49 AM
BAE Systems Microprocessors Enroute To Mars Ron Baalke Technology 0 July 29th 03 10:40 PM
Whats in the sky today [email protected] Amateur Astronomy 3 July 14th 03 04:24 AM


All times are GMT +1. The time now is 06:21 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.