Variable Stars

Following the mid-month meeting on 10th Nov here are some resources and suggestions for variable star observing:

Links:

The American variable star organisation and their beginners programme.

https://www.aavso.org/

 

https://www.aavso.org/sites/default/files/10startutorial-2013.pdf

 

 The SPA site and beginners programme.

http://www.popastro.com/variablestar/

 

http://www.popastro.com/variablestar/observingprogramme/index.php

 

Calculator to forecast minima times for Algol (when it is in eclipse)

http://lackawannaastronomicalsociety.org/varstar.htm

 Article by Gary Poyner.

 http://www.skyatnightmagazine.com/feature/how-guide/how-observe-variable-stars

 BAA variable star section, click on beginners on sidebar to go to beginners observing programme.

http://www.britastro.org/vss/

 

 To get started it was suggested that the following would make suitable targets, observing with naked eye or with binoculars (10×50)

Eclipsing Binaries:

Beta Persei (Algol), nightly observations but hourly either side of predicted minima ( see calculator)

Beta Lyrae, nightly observations, early evening , while still relatively high.

Pulsating Super Giants:

Delta Cephei, nightly observations.

Zeta Geminorum, nightly observations.

For all four targets see the SPA link ( 4th link-observing programme) for further notes and star charts with comparison stars, if you were at meeting you also have alternative star charts /comparison stars that were circulated.

Recording observations:

Date Day time Estimated brightness Estimated magnitude Conditions
07/03/10 1 22:30 Equal to epsilon and zeta perseus.

Dimmer than alpha perseus.

3.0 No moon, cold with low humidity, some high haze.
15/03/10 9 21:10 Brighter than epsilon and zeta perseus, but dimmer than alpha perseus. 2.2 Cold, no moon, high hazy cloud.
23/03/10 17 21:30 Brighter than epsilon and zeta perseus, but dimmer than alpha perseus. 2.2 Cool, light haze, moon first quarter, but 20Oto S.

 

 

Record in a similar format as above, compare variable to other stars on charts to get estimate of magnitude, remember lower the number the brighter it is.

Once you have collected enough data , have a go at plotting light curve, magnitude on vertical axis,with magnitude decreasing down the side , time on horizontal axis.

For Algol convert time from first observation  into hours, for the others days is fine.

Any queries come back to me, peter_j_hill@hotmail.com

 

Pete Hill

 

 

 

1 Response

  1. Thanks Peter. I found the second link (the pdf one) very helpful. I discovered last night that you don’t need a scope or binoculars to make the observations. (I missed the talk the other week.) Can you recommend a variable star chart, and where to get it from? Some of them are very expensive, and I don’t want to spend massive amount.

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