Circumpolar

[OzEclipse]

In recent posts, I posted two 30s exposure frames that were part of a star trail sequence.

Here is the stitched final star trail.

Ninety four 30s exposures over 60 minutes were taken to capture this star trail hovering over a distant canola field. The strange flare effects and fading star trails were caused by the gradual fogging of the lens from the heavy dew that night. The bright yellow glow above the canola field is a mine, the fainter blue glow is the town of Galong, NSW.

Cheers

Joe

[KathyNS]

Very nice!

I am not familiar with the southern sky. What's the big blue thing at the left?

[OzEclipse]

Very nice!

I am not familiar with the southern sky. What's the big blue thing at the left?

Hi Kathy,
Thanks. Now you know how we feel when we travel north. ;-)
It's Canopus, the second brightest star in the sky. Mv = -0.6
The gradually appearing blue haze and the tapering star trails are caused by fog forming on the lens.

Joe

[Greenman]

Amazing shot Joe, the larger image is just stunning.

[sdbodin]

Lack of a bright pole star is very obvious. Also, the Magellanic Clouds are far closer to the pole than perceived by us northerners. No wonder I could not see them when I lived in the 50th state, but Canopus was seemingly high in the sky.

Nice pic,
Steve

[OzEclipse]

Lack of a bright pole star is very obvious. Also, the Magellanic Clouds are far closer to the pole than perceived by us northerners. No wonder I could not see them when I lived in the 50th state, but Canopus was seemingly high in the sky.

Nice pic,
Steve

Thanks Steve. Yes at this latitude 35 S, they are circumpolar as is the Southern Cross, pointers and Eta Carina.

The lack of a bright pole star is an issue for beginners but two fainter pole stars (mags 6.8 & 7.8) are visible in a small polar finder and each equidistant and only a 8 & 9 minutes from the pole. After all, Polaris is about 40' away - not terribly close so you have to use those offset circles which I imagine beginners find hard to use. Down here, once you know these faint stars, it's easy to form a little isosceles triangle and just using the centre cross of the polar finder be within a minute or two of the pole. No messing around with offset graticules and setting the position angle by date. My EM200 has a drive that is considerably better that the ±5 arc sec PE spec. It takes me about 4 mins to polar align and then I don't even guide with lenses to 300mm. Very occasionally I have even done some prime focus with an 8" f6.4 and 2-3 minute subs without guiding.

regards

Joe