{"id":2848,"date":"2018-09-15T12:58:35","date_gmt":"2018-09-15T11:58:35","guid":{"rendered":"http:\/\/www.popastro.com\/main_spa1\/variablestar\/?page_id=2848"},"modified":"2018-09-15T12:58:35","modified_gmt":"2018-09-15T11:58:35","slug":"two-stars-in-hercules","status":"publish","type":"page","link":"https:\/\/www.popastro.com\/variablestar\/two-stars-in-hercules\/","title":{"rendered":"Two Stars in Hercules"},"content":{"rendered":"
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Chart for G Herculis<\/figcaption><\/figure>\n

G Herculis.<\/strong><\/p>\n

G Herculis is a semi-regular variable star with a range of 4.30 – 5.50 and a period of 90 days. As with all semi-regular stars the figures are just a guide and G Herculis may fluctuate outside of these values. Although I’ve never seen it exceed magnitude 4.3 in brightness, I have seen it become as faint as 6.3. The period of 90 days will be a mean value averaged out over the course of many periods. Any given period may be shorter or longer then this.<\/p>\n

As finder chart shows, the keystone of Hercules is made up of the four stars Pi, Epsilon, Zeta and Eta Herculis. Locate Eta Herculis, which is the top right star of the keystone, below this star you’ll see the faint fuzzy patch of M13 and above and to the right of Eta is the star Sigma Herculis. G Herculis makes a triangle with Sigma and Eta Herculis. As Sigma Herculis has a magnitude of 4.2 it may be visible to the naked eye; if your skies are dark enough. This will make identifying G Herculis a lot easier. Of course, if your skies are that dark, G Herculis itself may be visible with the naked eye! However, it is still best to make magnitude estimates with a pair of binoculars.<\/p>\n

 <\/p>\n

UW Herculis.<\/strong><\/p>\n

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Chart for UW Herculis<\/figcaption><\/figure>\n

An even easier star to find is UW Herculis, which is located just under Pi Herculis, which is the star in the top left-hand corner of the keystone. UW Herculis is another semi-regular star with a range of 6.8 – 8.7 and a period of 104 days. UW Herculis is fainter then G Herculis and may not always be visible in small binoculars, but I can see it with my 10×50 binoculars, even when it’s at its faintest, despite my moderately light-polluted skies. Again, the figures above are just a guide and the magnitude range is an extreme range, the star may not vary as much as this. I’ve yet to see it exceed magnitude 8.0. However, it is the unpredictable nature of semi-regular stars which makes them so interesting to observe.<\/p>\n

If what to try or hand at observing these stars, or any other stars on the SPA program list, then do send your observations in.<\/p>\n","protected":false},"excerpt":{"rendered":"

G Herculis. G Herculis is a semi-regular variable star with a range of 4.30 – 5.50 and a period of 90 days. As with all semi-regular stars the figures are just a guide and G Herculis may fluctuate outside ofRead more<\/span><\/a><\/p>\n","protected":false},"author":22,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[],"tags":[],"class_list":["post-2848","page","type-page","status-publish","hentry"],"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