brief observations notes & Some Doubles in Cancer

[lunator]

Have managed to get out 3 nights in a row :shock:

The night of the 1st was by far the best conditions but last night had was ok.

Due to the mist and cloud tracking down faint objects was going to be a futile exercise.

I started Procyon and dropped the scope to the equater to align the position angle dial.

I started with HJ2302. As I am determined to measure this pair physically not just by the Aladin database but tonight the secondary was not visible even with averted vision.

After 20 minutes of trying to shels my eyes from sray light I realised that tonight anything fainter than 10.5 was not visible. I had a quick look at Beta Mon the triple but it was getting so low that the tight pair were quick tricky to split.

I decided to spend some time looking at some double in Cancer.

I started with the bright pair iota. A lovely wide Ornage primary and a pale blue secondary a beautiful contrast and very easy to split. It can be done in binoculars. I took some measurements and the results are within 1% of the current WDS values.

I moved across to STF1223 (Phi 2 Cnc) a close pair of matching white stars.

Further down I had a brief stop at Saturn (no photos taken) When the seeing was good you could see the belts on the surface. It has also been interesting to watch the movement of the Satellites over 3 consecutive nights. A couple of night ago a couple of the Moons were very close to each other just to the North East and from using the diagram in Sky & Telescope it appears they were Enceladus & Dione. Titan was further over to the East as well.

Below Saturn is the double HJ2452 (HJ stands for John Herschel) it is more commonly known as Theta Cnc. It is a wide double with a yellow/orange primary & a faint (possibly blue) comapnion. I have check the spectral class of the primary this morning and it is a K5 giant so the colour I saw was correct. I took some measurements and the calulations came out at 63 degrees PA and a separation of 69" (WDS 70.4/62 fromm 1988). I am going to re-visit this pair to re-evaluate the figures. The secondary was quite difficult to observe with the illuminated wires and I reckon I can refine the data.

I had a look at Zeta Cnc but the tight pair were only elongated at x266 so I decided to move up to the great bear.

1st stop was Xi Uma a close pair of Orange stars with an orbital period of 60 years ( the 1st to be calculated). The seeing meant that they were not clearly split but 2 stars could be observed.

My final star was a wide double KZA 11.

It was observed in 1984 and has not been observed since. The Primay is a 7.6 mag star so is relatively easy to find. The soconday is a mag 9.6.

I took some measurements and whilst the PA agreed - 250 degrees the separation was significantly different I made it 62" the WDS has 43.2".

It was about 1.00am and -4 when I was taking the measurements so I they could be cold/fatigue affected. I will be re-visiting this star again very soon.

Cheers

Ian

[Saso]

Thanks for sharing. Nice report. 3 nights in a row. Very lucky.

Saso

[The Warthog]

Nice report. Glad you got out.

[Naz]

Three nights in a row, I vaguely remember times like that, three nights in a row, hmmmmmm!

Good report and a good read Ian

nabban