Thanks for your comments John.
So, two challenges for me, south of Hobart. Orion will be at only 46 degrees elevation just after dark. The second and bigger challenge is to find a large enough suitable scope!
I am attending the SPSP in May, so perhaps there may be an opportunity then.
Cheers
Steve.
Quote:
Originally Posted by ausastronomer
Steve,
I have observed H1,H2 on quite a few occasions in one of our 25" Obsessions. I have also observed them on a couple of occasions in Andrew Murrel's 20" Hector and my own 18" Obsession. They are very difficult in any scope under 18".
There's a bit of a trade off here. You need plenty of aperture, the more the better. The rub here is that the bigger the scope the harder they are to cool and keep in thermal equilibrium where you can crank up the power, with sharp stars.
I have found the best time to try them is when Orion is high in the sky just after dark. In the Southern hemisphere this occurs late summer / early autumn. Now is a great time if you have the necessary aperture. You need Orion to have the elevation but you also need to try before the air temperature starts to drop rapidly and take the big scopes out of thermal equilibrium, particularly if you are at any sort of elevation above sea level as the temperature delta is larger from day to night.
Of course the other important factors in addition to the above, are good optics, good eyepieces, good target elevation, good seeing, good transparency, good eyes and a finder chart so you know where to look if you haven't been there before.
Cheers,
John B
|