Category Archives: My Astronomy

The Twin Quasar

Posted on by July 20, 2021

I followed an online mission to the Twin (Double) Quasar and took an image. I was not quite sure which of the bright dots represented the quasar. Fellow Slooh members introduced me to Aladin, the interactive sky atlas and I could identify the object easily.

“The Twin Quasar was discovered in 1979 and was the first identified gravitationally lensed object. It appears as two images, a result from gravitational lensing caused by the galaxy YGKOW G1 that is located in the line of sight between Earth and the quasar” – Wikipedia

The quasar lies about 14 billion light years from Earth in the constellation of Ursa Major. The huge elliptical galaxy YGKOW G1 lies directly between Earth and the quasar at 4 billion light-years away and acts as a gravitational lens. Its mass is so great that it can bend the light from objects lying behind it.

I so enjoyed a course Intro to Astro on Slooh by Dr Paige Godfrey where one of the topics was gravitational lensing. Now I have a practical example to add to my notes.

 

 

Messier Marathon at Slooh

Posted on by July 20, 2021

Well I did it! 17 March 2018 – a night to remember

  • I have become an astronomer member at Slooh and am able to reserve slots with objects of my choice on the Slooh telescopes which are situated on the Canary Islands and in Chile.
  • Slooh members were given the challenge to do a Messier Marathon over the course of one night! – we had to target all 110 deepsky objects in Charles Messier’s catalogue. The targets were divided between members and Slooh. Members are able to take images of all the objects on which the telescopes are focussed at any given time whether you reserved the slot or not. Then came the downloading and processing of all 110 images.
    The template was provided by Slooh, originally designed by Andrew Dumbleton and modified by Paul Cox.
    Processing: some sharpening here and there where stars were really “runny”, some filters on the open clusters to give a more varied appearance and finally cropping to fit into the tiny boxes.
    The quality on some of the shots are an indication of the high wind gusts that the domes had to withstand on the night.
    The very best yet also the worst image is M30. It was touch and go or we would not have been able to complete the entire catalogue. M30 was just 3° (I think) above the horison and our one and only chance to get the image.
    This has not been a walk in the park challenge but so rewarding. I can’t believe I’ve completed a Messier Marathon.
    Note to my deep sky mentor, Auke Slotegraaf – at least I did not try to sketch these 😉 but then it would have earned me an Astronomical Society of Southern Africa Certificate – that’s for sure!