After two days of rain, thunder, and howling wind I looked out the window around 9 pm last night and saw stars. Stepping out into the front drive, I could see some clouds low in the west and south, but the sky was mostly clear and the air calm. This was a surprise -- earlier in the evening I had the oil lamp lit because power was out, likely from the stormy conditions. I used this unexpected opportunity to take an image of a star that has been on my observing list for a while.
HD 162826
HD 162826 is a 6.5 magnitude star in the constellation Hercules, about midway between the keystone asterism and the bright star Vega. It is just beyond the limits of naked-eye visibility, but easily found with binoculars. It is not bright enough to have a name, just a catalog number. The "HD" part of its designation refers to the Henry Draper catalog from Harvard College Observatory, which was compiled about a century ago.
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| E-M5iii + Lumix 20mm f1.7, 60 s, ISO1600, binned by two and cropped square. Kenko Pro softon-A filter. |
What makes this otherwise innocuous star interesting is that it is most likely a sibling of our own sun, born at the same time from the same molecular cloud 4.6 billion years ago. It is now 110 ly away, but it and our sun would have been part of a loose open cluster of stars at their time of formation. Since then our sun has circled the galaxy about twenty times and the original cluster has widely dispersed. The identification as a solar sibling is based on the chemical composition deduced from spectroscopic studies, which shows elemental abundances virtually identical to our sun.
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| E-P5 + Rokinon 135mm f2. 30 s, ISO1600. 2-deg square. |
An hour after this photo I looked out the window again. The clouds had closed in and the stars and surrounding hills were invisible.
The morning after:
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