Observation by Dr Paul Leyland: The Cosmic Horseshoe - a bright gravitat...

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Dr Paul Leyland


Dr Paul Leyland


2023 Feb 24 - 22:48


2023 Feb 25 - 23:54

  • 0.4m Dilworth Relay
  • SX 814 CCD camera
  • No filter

6180 seconds.


Tacande Observatory, MPC J22

Target name

The Cosmic Horseshoe, aka SDSS J114833.14+193003.2


The Cosmic Horseshoe - a bright gravitational lensed galaxy.

About this image

The Cosmic Horseshoe is an unusually bright Einstein ring, where one object lies almost directly in front of a background object. In this case the foreground galaxy is particularly massive and is as bright as g=20.8 despite being 1.6Gpc or 5.2 billion light years away. The light of the more distant galaxy is greatly magnified by the lensing effect and is readily visible, despite being at twice the distance  --- 3.2Gpc or 10.3 billion light years.  The corresponding red shifts are 0.4457 and 2.379 respectively.

More details available at https://en.wikipedia.org/wiki/Cosmic_Horseshoe and a nice image can be found with https://aladin.u-strasbg.fr/AladinLite/ --- the DSS2 image there is more colourful than mine but shows no more detail.

I claim that this is a genuinely Deep Sky object.


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Dr Paul Leyland
Dr Paul Leyland, 2023 Feb 26 - 14:41 UTC

Note: the Einstein ring is only 10 arcseconds in diameter.

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