Observing Session 21/02/2009

[lunator]

Observing Report 21/02/2009

Seeing III/V Transparency III/V

No Moon, occasional medium level cloud.

The forecast was finally showing clear skies for the evening and at dusk Venus was a bright white ‘star’ high in the West.

By 8pm I was able to get out. I rolled the rolled the roof of the observatory and removed the scope cover.

I purchased the Cambridge Double Star Atlas at Astrofest and I wanted to use it as a basis of an observing session. I did not want to get the book damaged so I scanned the 2 pages covering most of Taurus, Gemini and Auriga.

I started with a look at M45 just to make sure everything aligned and it was good to see this sparkling gathering of stars again.

I Moved on to the 1st target.

STF572 F2V/F2V 7.36/7.21

Primary – White

Secondary – White

A closely matched pair separated by around 5”\both stars appear as the same colour.

In the 24mm (x94) the 2 stars were nestled together.

The surrounding field seemed very sparse.

STF623 B7V+A0V 6.98/8.72

Primary – White

Secondary – Orange

A wide pair easily split at low magnification. A scattering of faint stars to the North East.

STF 645A-BC A5m 6.04/9.11

Primary – Cream

Secondary – Orange

The pleasant colour contrast, the pair are easily split in the 24mm (x94) a good target for small scope. A few faint stars dotted around.

STTA 61 F8V 6.72/8.49

Primary – White

Secondary – Blue-ish

Very wide pair, The pair makes a nice triangle with a faint star to the North.

STF653A-C A9IV/F3V 5.03/7.33 (14 Aur)

Primary – Pure White

Secondary – blue/white

A fairly wide pair of uneven magnitude, the surrounding field is very rich in faint stars. The B component (11.1 mag) was not observed.

STF719A-C G5 7.5/9.39

Primary – Yellow White

Secondary – White

A very subtle colour contrast this is a wide-ish pair easily split in 24mm (x94). A nice curving chain of stars to the North. The close B component was not observed.

STF753AB-C F9III+B9.5/A2V 5.46/8.42

Primary – Pale Yellow

Secondary – Pale Blue

A moderately wide pair separated by 12”. The pair shows a pleasant colour contrast. There are several bright stars in the field of view.

STF764 B8IV/A? 6.38/7.08

Primary – White

Secondary – White

A wide pair separated by over 26”, with a moderate difference in magnitude. A trail of bright stars to the South.

BU14 F8IV 7.3/10.5

Primary – Cream

Secondary – Orange?

A tight-ish pair separated by 5.5”. In the 24mm the 2 stars are nestled next to each other. The pair was easily split in the 12mm (x187). The colour of the secondary disappears in the 12mm. The view in the 24mm is very rich.

BU560 F8 7.77/8.24

Primary – Creamy White

Secondary – Off-White

This a very close pair that could just be split in the 12mm (x187) the separation of 1.6” would make this a tough split for a small scope. The field around the pair is quite rich.

STF783 B5 8.05/9.7

Primary – White

Secondary – n/c maybe a hint of orange

The moderately wide pair separated by 8.5” with a noticeable difference in magnitude. The surrounding field is rich in faint stars.

STF796 A3 7.24/8.23

Primary – White

Secondary – White

A fantastic view in the 24mm (x94) A close pair (4”) of similarily coloured stars in a very rich field. Both stars appears white with the secondary showing a slightly warmer tint. A Neat U-shaped asterism to the West, this pair is very close to M37.

STF782 F4IV 6.89/7.38

Primary – White

Secondary – White

A pair of white stars separated by around 11” with a magnitude difference of around 1, the field is quite rich to the East and there is a long stream of stars to the West-South West.

STF950AB O7 4.64/7.79

Primary – Blue-white

Secondary – White

A close double (2.9”) also known as S Mon. Part of the Christmas tree cluster. There are many components to this star. It looks like a small cluster.

STF921 B2V/A5 6.12/9.09

Primary – White

Secondary – Off-White

Close to the Christmas tree cluster. The pair is fairly wide (16”) and of uneven magnitude. There is a neat triangular asterism to the South East.

STF899 A0V 7.41/8.01

Primary – White

Secondary – White/cream

A tight pair of white stars, elongated in the 24mm (x94) but split cleanly in the 12mm (x187). This would be a good test of a small scope.

STF1061 (Lamda Gem.) A3V 3.58/10.7

Primary – White

Secondary – nc.

A wide but uneven pair. Appeared close in the 24mm due to the glare of the primary. In the 12mm the split was wide. The view surrounding the pair is rich with a triangular asterism very apparent to the West.

STF1094 A0V 7.58/8.52

Primary – White

Secondary – White

A tight pair that could be split in the 12mm (x187) when the seeing settled, The primary appeared a slightly cooler shade than the secondary. There is a neat trapezoid shape asterism to the South East.

STF1083 A5 7.32/8.13

Primary – White

Secondary – Cream

A moderately wide pair of stars about 7” apart. The secondary appears a warmer tint than the primary. The field was quite sparse.

STF1053 A0 7.35/10.83

Primary – White

Secondary – no colour

A wide pair (14”) close to 52 Gem. The pair is uneven in magnitude and is easily split in the 24mm (x94). The field is quite rich with a line of stars to the West.

Cheers

Ian

[Doc]

Very interesting report Ian.

Lots of good information as well.

[mdstuart]

What would be a good test for my 10 inch dob?

[lunator]

With a 10" scope the atmosphere may well be more of a limiting factor than the scope resolution.

Last night the seeing was not great and spliting a 1.6" double was only intermitent.

Rgds

Ian

[almach]

Great report mate. I'm amazed how many you can pack into one session. Let me guess, practice, practice and more practice