2018 May 14 ~ The Southern Cross and the False Cross

****************************************************************************

Photographed outside Uluṟu-Kata Tjuṯa National Park, Northern Territory, Australia (440 km by road southwest of Alice Springs), long. 131.04° E., lat. 25.22° S., between 23.20 and 23.42 CAST (Central Australian Standard Time)

 

* Altitude of centre of frame at time of exposures: 46°

* Temperature 11° C.

* Total exposure time: 10 minutes

* 50 mm focal length lens

___________________________________________

 

Description:

 

Both astronomers and casual sky observers enjoy drawing lines between nearby stars and forming star patterns in their minds. A very obvious star pattern for observers in the southern hemisphere is the Southern Cross, formed by three very bright stars and one fainter one in the constellation Crux (the Cross).

 

The Southern Cross appears near the left edge of the frame, just above centre. For a close-up view of this star pattern, click here:

www.flickr.com/photos/97587627@N06/28578438088

 

Larger and not as obvious, at the right side below centre in this view, are the four fainter stars of the False Cross, which is often mistaken for the Southern Cross because it rises in the southeast a couple of hours before Crux does.

 

Just above centre in the middle of the frame is the red-pink hydrogen emission nebula surrounding the variable star Eta Carinae. For a close-up view of this nebula, made three nights earlier, click here:

www.flickr.com/photos/97587627@N06/41615329630

 

And at left, side by side, are the two first magnitude stars Alpha and Beta Centauri, which are the 3rd and 11th brightest stars in the sky (other than the Sun).

 

This is the telescope and mount that I used for my astrophotography on this trip:

www.flickr.com/photos/97587627@N06/28602350028

 

For a version of this photo WITH LABELS, click on your screen to the RIGHT of the photo, or click here:

www.flickr.com/photos/97587627@N06/43436255575

__________________________________________

 

Technical information:

 

Sigma 50mm f/1.4 DG HSM Art Lens on Nikon D810a camera body, mounted on Sky-Watcher HEQ5 equatorial mount with Kirk Enterprises ball head

 

Ten stacked subframes - each frame:

ISO 4000; 1 minute exposure at f/4.5, 50 mm focal length, unguided (with LENR - long exposure noise reduction)

 

Subframes stacked in RegiStar;

Processed in Photoshop CS6 (curves, levels, brightness, contrast, colour balance, bright star flare reduction)

****************************************************************************

Done