Locating the Southern Pole Star

From Paul's Backyard in Caboolture, QLD, Australia

Uploaded 7/25/09

This image is looking due south from -27S latitude in Pauls Back yard. Centered in this wide angle shot is Sigma Octans, the south pole star. Sigma is quite faint - a class F star of 5.5 magnitude and not visible to us from his somewhat light polluted sky overlooking Brisbane. In binoculars, its not too difficult, and photographically in this 30s exposure you can see it clearly. Even more interesting is that while Sigma is still a degree away from the true pole, there is a very red class M4 type star, at 6.9 magnitude that is only 15 arcminutes from the current pole. This star designated HD110994 would make a great star to bore sight with an equatorial mount for alignment.

Compare this with our northern pole star, Polaris which is a bright 2nd magnitude and 3/4 degree from the true north pole in the sky.

Here is the original image, looking due south over a huge pine tree in the backyard. Select an image size for a larger view: 1290 x 960
In this image I have labeled the constellations and the two polar stars of interest. Select an image size for a larger view: 1290 x 960
When we zoom in on sigma octans you can see that HD110994 has a very red color.
Lens: Sigma 18 - 200 @ f/5.6 and 18mm Camera: Canon 10D @ ISO800 Mount: Camera Tripod Exposure: 30s Filters: None Location: Caboolture, QLD, Aus Elevation: 50 ft. Sky: Seeing 7/10, Transparency 6/10 Outside Temperature: 60F Processing Tools: Photoshop CS2, Maxim DL HOME GALAXIES EMISSION NEBS REFLECTION NEBS COMETS GLOBULARS OPEN CLUST PLANETARIES LINKS