Serendipity – Broken Glasses and the Pleiades

Yesterday I bought an used 150/750 Newton telescope, of course I got it rather cheaply (this *is* Cheap Astronomy, after all). The 150/750 telescope is everything it promises: a large mirror in a cheap package, with quite a few quirks – it will be fun playing around with it.

I choose a scenic route back from the seller (having no chance to do otherwise an vacation, this was quite nice), and while I was exhausted from the journey I had to try out the new scope at the night sky. And then it's when it happened: I had the glasses rather carelessly on top of my head, they fell down and broke (right in the middle) into two pieces. Though I don't need them to look through the scope (and prefer rather not to wear them at the eyepiece) they are necessary for me to look with the naked eye at the night-sky. Without glasses, the stars are quite blurry – which proved to be a fortunate accident. When I later scanned the night sky with the truly naked eye (after having possibly seen the California Nebula in the 150mm Newton) I stumbled without glasses upon the Alpha Persei Cluster, (aka Mel 20, Melotte 20 or Collinder 39) the Pleiades.

[Update] I am such a noob. I got side-tracked in my star-charts and can't properly tell altitude. The object I saw was much lower in the sky (about 20 degrees) than Mel20 (about 45 degrees) – it was the Pleiades! In a 70mm scope at 12x magnification they look a little bit different than the photos: much more lively. Though I should have recognized them in the binoculars. Doh. m( Thankfully nobody reads this. :-) [/Update]

For me, without glasses, the Pleiades seem like a longish blur, a bit reminiscent of an elongated galaxy – standing out quite clearly against the night-sky. There is something there! I grabbed my 7x60 binoculars, and sure enough there is a nice star cluster there.

Next my modified 70/300 refractor came in rather nicely. With a 25mm Plössl (at 12x magnification) it was splendid. The refractor revealed more than my (bad, bad) 7x60 binoculars, showing the brilliance of the stars in that cluster rather nicely.

What is important to have a large field of view to reveal the contrast between the star-rich cluster and the "normal" night-sky with a lower star density – if you yank up the magnification then the star cluster will look like any other star-field… Though (at 300mm focal length) a PL30mm, PL32mm or PL35mm eyepiece would probably be nice, as with the lower magnification (10x, 9.4x or 8.5x respectively) it might reveal more of the surrounding sky, and frame the cluster better.

I must say, the Pleiades are a night-sky target well suited for binoculars and small telescopes with low magnification (in the range between 7x and 15x) – highly recommended eye-candy!

[Update 2013-10-05] Now that I know what to look for I took another look a the Pleiades yesterday. Some cloud-ish something was hanging in the East and the view of the Pleiades wasn't nearly as vivid as I the first time I saw them. I could have sworn: the first time I say the Pleiades I thought I could discern different star colors. Mainly blue for the brighter ones, but some orange-ish dimmer ones interspersed. (I think my memory is playing tricks on me).

No colorful stars yesterday, and much less vivid – the weather was not as good last night. At both nights I tried the Pleiades with the 70/300 Refractor and a PL25mm (12x magnification) and my new 150/750 Newton and the same eyepiece (30x magnification). The 5.9 inch Newton is significantly brighter, as was to be expected. The images at that magnification are good in the 5.9 inch Newton, but of course the Pleiades now fill the entire FOV of the Plössl. A PL32mm or maybe a PL35mm would be a welcome addition to my eyepiece collection – maybe for Christmas. :-)

I am very happy to have bought that cheap 150/750 Newton. The EQ-3-1 mount and tripod isn't great, but I got it to behave with some small mechanical modifications.

On the first night I saw the Pleiades I tried the little 76/350 Newton as well (which has an effective aperture of about 60mm) and I must say the images are not good compared with the 70/300 Refractor (which is a badly collimated instrument). Viewed through the focuser's tube it is obvious that the secondary of that little Newton is too much to the front. The primary is not adjustable (at least without some DIY modifications) – but adjusting the secondary might help a lot.