Good day to one and all.
Once again I set up my William Optics 158 mm F/7 apochromatic refractor in my back garden with its WO 70 mm F/6 small apo both placed on the Berlebach Planet alt-az mount. I observed from 9.30 pm until 11.45 local time. In the end the temperature had dropped to 2˚ C. There was no wind.
1. Of course Venus had to be observed first. It is now less than 82 million kilometres from Earth. 38.1% of her was illuminated. Her angular diameter was 30.5” and is of -4.7 in magnitude. At 40X I was fitting the double star Chi Tauri which was split in the same fov as Venus. Its magnitudes are: A = 5.4. B = 8.5. Sep = 19.4”. PA = 25˚. The planet was noticeably shimmering at 167X; but I did see it had bright cusps.
2. Some amateur astronomers have been observing Eta Geminorum (Propus) over on
www.cloudynights.com
. So I thought I would gave it a go. Its magnitudes are: A = 3.5. B = 6.2. Sep = 1.6”. PA = 251.5˚. A has a spectral class of M3. It is a very fine red star. There is no sign of B at 112X. But at 140X, something is beginning to happen. The B star is trying to “pull” away from A. Success was to be had at 167X and 225X. It was a beautiful sight. There was a tiny black gap between the 2 stars at both those magnifications.
3. Now it’s up to Lynx. I had been forgetting how wide this constellation is. I soon discovered that my 2nd carbon star in Lynx is close to the neighbouring trees. But I did succeed in locating and observing BD Lyncis. It is a variable star but not by much. Its magnitude varies from 9.9 down to 10.4. Its alternative designation is TYC 3412 2402 1. My Guide 9.1 DVD recognises that second designation; but of course others can be found on Simbad. It is my 87th carbon star which I have observed. I found the star at 40X with plenty of field stars in the area. It was relatively easy to locate. It was a very nice way of commemorating my 13th wedding anniversary to my wife Valerie. It surely was the first time I had observed any carbon star right on the same day of our wedding anniversary. And I am delighted to state my wife Valerie joined me in the back garden to observe BD Lyn. I also used magnifications 112X, 140X, 167X, 225X and 280X on this very good carbon. At those 2 highest powers I discovered the star was very attractive and it was, and is, a substantially rich orange carbon star. I was planning on observing some new double stars in Lynx, but I will keep that to another night.
4. Over our house, I could see Alpha Canum getting higher. It is a true binary with magnitudes: A = 2.9. B = 5.5. Sep = 19.5”. PA = 230˚. The star has a splendid name: Cor Caroli which means the Heart of Charles. Charles refers to King Charles 1st. It might have been named by our comet hero Edmund Halley. No one is sure about that. The 2 stars have spectral classes A0 and F0. Therefore if there are any colours to either star they must be very slight. Valerie and I agreed the primary is a stunning white with no blue colour at all. B, however, did have a very slight yellow coming through at 112X. As we know, apochromatic refractors love to kill false colours. Other scopes probably will differ on this splendid double.
5. Our final celestial object was the magnificent globular star cluster M3. It was very easy to locate moving my scope downwards from Alpha Canum. I used powers right up to 280X on this very famous cluster which contains about 500,000 stars. Its diameter is 18’ and is of magnitude 6. It is extremely bright, very large, extremely rich, extremely compressed and resolved all the way to the centre even at 167X. Its brightest stars are of magnitude 11. If our Sun was placed in this globular it be of magnitude +20.4. Charles Messier first observed it in 1764. Its distance is in the range of 35,000 to 40,000 light years and it has a diameter is 220 light years.
It certainly was a fine way to end an observing session.
I won’t be doing any observing tonight Wednesday 15th April.
I have something else on.
But I’m sure I will have further opportunities soon again.
Thank you for reading.
Comments are always welcome.
Clear skies from Aubrey.
