Black Hole, After Much Frustration!

[cloudsweeper]

Set up the Bresser Dob before mealtime, hoping for the Moon and Cygnus targets, but it got very cloudy very quickly, so I packed up.

After the meal, the sky was teasingly clearish again, so this time I put the ST120 frac into service - a fine telescope for dimmer objects (no CA), and very easy to set up and use.  Managed a few nice views of the Moon, but I really wanted the Eta Cygni region.  In a very wide view, I spotted a "question mark" of faint stars, which led me to Eta Cyg.  In the same FOV (and about half a degree away) was Cygnus X-1 (V1357 Cyg) at the tip of an arrowhead of stars.  I was delighted to grab a window and be able to see this......

It is an X-ray binary -  a blue supergiant (no colour detected) with a Black Hole in close orbit (period 5.6 days).  It was the first confirmed BH, and the subject of a bet between Hawking and Thorne, which Hawking lost in 1990 when observation strongly indicated the presence of a BH.  (Sources: Wiki; Constellations [Sparrow]; Stars [Dorling Kindersley].)

When conditions are more favourable, I shall return to this region.  But seeing the location of a BH was extremely exciting, and recommended to anyone who hasn't yet done so!

Doug.

Edited November 6, 2019 by cloudsweeper

[Paz]

Cygnus X-1 was on my list of things I always wanted to see - although it's nothing special visually, as you say it is interesting to think about and to know what you're looking at.

Robert Burnham wrote about Cygnus X-1 before it was definitively considered a black hole, saying it was "..probably the most convincing candidate..." for one, and now we are lucky enough to know!

[Hayduke27]

Cygnus X-1 has been on my list for over a year.  Although I understand you can't see a black hole, I sure would love to get the EP onto that piece of sky and just stare it it for a little while knowing what is there.