{"id":219,"date":"2015-06-13T22:40:50","date_gmt":"2015-06-13T21:40:50","guid":{"rendered":"http:\/\/www.vss.popastro.com\/?page_id=219"},"modified":"2024-04-30T13:34:03","modified_gmt":"2024-04-30T12:34:03","slug":"choosing-stars-to-observe","status":"publish","type":"page","link":"https:\/\/www.popastro.com\/variablestar\/reference\/choosing-stars-to-observe\/","title":{"rendered":"Choosing stars to observe"},"content":{"rendered":"

Which type of variable star is suitable for you<\/u>?<\/strong><\/span><\/p>\n

This depends on how often you can observe <\/strong>in a given month\u00a0and how long you can observe for on each occasion<\/strong>.<\/p>\n

The variable stars on the programme of the SPA VSS can be divided into five categories<\/strong>:<\/p>\n

1. One-Nighters<\/strong><\/span><\/p>\n

\"\"
Tracie Heywood’s light curve for the Primary eclipse of RZ Cas on 2018 Jan 8<\/figcaption><\/figure>\n

These are stars for which it is possible to see significant variation in brightness in the course of\u00a0several hours on a single night<\/strong>, although not necessarily on every night.<\/p>\n

This category includes RR Lyrae and the Algol type eclipsing variables.<\/p>\n

One such eclipsing variable is RZ Cassiopeiae, whose primary eclipse is shown in the accompanying light curve.<\/p>\n

In the case of RZ Cas, the whole eclipse lasts for nearly 5 hours but, as can be seen in this light curve, most of the brightness changes occur during the middle 3 hours.<\/p>\n

Algol (beta Persei) is the most famous example, although its eclipses are about twice as long as those of RZ Cas.<\/p>\n

2. One-Weekers<\/span>
\n<\/strong><\/p>\n

\"delta
All observations from 2016 combined into a single light curve showing the 5.37 day cycle<\/figcaption><\/figure>\n

These are stars for which significant changes in brightness can\u00a0be seen over the course of a week or two, in some cases from one night to the next.<\/p>\n

These would suit people who are able to observe on every clear night, but only short a short time<\/strong>.<\/p>\n

This category includes the Cepheid variables, such as Delta Cephei, \u00a0and the beta Lyrae type eclipsing variables.<\/p>\n

 <\/p>\n

3. Medium-Rangers<\/strong><\/span><\/p>\n

\"\"
A 5-year light curve for the semi-regular variable Z UMa<\/figcaption><\/figure>\n

These are stars that vary more slowly, but which show significant changes in brightness over the course of several months or a year.<\/p>\n

The brightness changes don’t repeat exactly from one cycle to the next, although there are clear signs of periodicity, all is illustrated by the accompanying light curve for Z Ursae Majoris.<\/p>\n

Sometimes these stars spring surprises – by brightening beyond the published upper limits of their brightness ranges or fading below the published lower limits. <\/p>\n

They would suit people who can observe several times per month, but not necessarily on every clear night<\/strong>.<\/p>\n

This category includes R Scuti and the semi-regular variables.<\/p>\n

4. Big-Rangers<\/span><\/strong><\/p>\n

\"\"
A 5-year light curve for the\u00a0 Mira type variable Chi Cygni<\/figcaption><\/figure>\n

These are stars that show large changes in brightness over the course of a year.<\/p>\n

Their brightness changes are so large that for several months they become too faint to be seen using binoculars and are only visible telescopically.<\/p>\n

The accompanying light curve for Chi Cygni shows its brightness changes during 2018 and 2023. The maxima were observable using binoculars, but a telescope was required to follow it down to minimum.<\/p>\n

These stars would also suit people who can observe several times per month, but not necessarily on every clear night<\/strong>.<\/p>\n

This category includes the Mira type variables.<\/p>\n

5. Rebels<\/span><\/strong>
\n<\/span><\/strong><\/p>\n

\"R<\/p>\n

These are variable stars that are totally unpredictable.<\/p>\n

These variables would mostly appeal to people who can observe on every clear night<\/strong>, but other observers may also enjoy monitoring them<\/strong> when their circumstances permit.<\/p>\n

The category includes R Coronae Borealis and Novae.<\/p>\n","protected":false},"excerpt":{"rendered":"

Which type of variable star is suitable for you? This depends on how often you can observe in a given month\u00a0and how long you can observe for on each occasion. The variable stars on the programme of the SPA VSSRead more<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"parent":78,"menu_order":0,"comment_status":"closed","ping_status":"open","template":"","meta":{"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[2],"tags":[],"class_list":["post-219","page","type-page","status-publish","hentry","category-variable-stars"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t