Help with viewing night tonight.

[batema]

Hi,

I have a viewing evening for next years Yr 11 Physics students and I like to start of with a single star and then go to Alpha Centauri to show a double. However I believe that this option is no longer available becaust of trees that are about 30 degrees to alpha centauri. Could someone suggest another double star option that is above this in terms of degrees and ease of finding.

Thanks

MArk

[Outbackmanyep]

If you have a good northern view try for Albireo in Cygnus, its a very nice contrasty pair!
Go to: http://www.skymaps.com/downloads.html
Scroll down the page to:

The Evening Sky Map
Southern Hemisphere Edition
(http://www.skymaps.com/skymaps/tesms0910.pdf)
And download the PDF file (select English)
If you get the finder chart at that link you'll find Albireo in the North above Vega on the chart, you can also download the chart for hand-outs!

[Coen]

I've always been partial to Acamar (theta 1 Eri) but at a little over 3rd mag it is fainter.

Depending on time and your view north you could try Albireo (beta Cyg) and Almaak (gamma And) or the optical double Mesarthim (gamma Ari)

Other options include beta Tuc (multiple) and Graffias (beta Sco)

[ngcles]

Hi Mark,



I'd suggest Acamar -- Theta Eridani

Acamar Theta Eri SAO 216113 HD 18622
RA: 02h 58m 15.720s Dec: -40° 18' 17.00"
Mag(v): 3.22 B-V: +0.156 Spect: A4III+... Alt: -15.8°, Az: 181.6°


PZ 2 RA: 02h 58m 15.7s Dec: -40° 18' 17"
Components: --- Mags: 2.9 / 4.0 Spect: A4III A1V # Obs: 60
Obs Dates: 1835 / 1997 Sep: 8.3 / 8.3 p.a.: 82 / 90

Which should be at about 30 degrees elevation at about 8pm EDST. Is the brightest star in its locale so easy to find approx 1/3 of the way from Achernar (Alpha Eri) to Rigel (Beta Ori).

A little later on, perhaps Gamma Arietis?

STF 180
RA: 01h 53m 31.8s Dec: +19° 17' 39"
Mags: 3.9 / 3.9 Spect: A1pSi B9V # Obs: 99
Obs Dates: 1821 / 1994 Sep: 8.6 / 7.8 p.a.: 358 / 1


Best,

Les D

Edit:

Beat me to it Coen -- must have sneaked in while I was typing.

[Coen]

From a physics perspective you could point the 'scope at mu1 Sco. Whilst visually it is not a double (although mu2 is nice and close making a naked eye optical double mu1 Sco) mu1 Sco is an eclipsing binary of a period of about 1.45 days and is part of the Sco-Cen OB association that we (as in Sun) is travelling through at the moment. It is suspected it has only just arrived on the main sequence and it is unusual in the sense that the secondary (the lighter mass star) is physically larger just filling its Roche Lobe. One star weighs in at around 8.5 solar masses, the other 5.3 and the semi-major axis of the circular orbit is 8.5 million kilometres. The system may have just undergone mass transfer.

Lots of physics that could be discussed.

[ngcles]

Hi Mark, Coen & All,



Indeed -- and if you are looking for a handy resource on this, search no further than May/June 2009 Australian Sky & Telescope Magazine p50 where some fool gave it a bit of a write up ...

Best,

Les D

[batema]

Thankyou all

Mark