Field of View

[rikpotts]

A friend recently bought a Skywatcher 200p and we are having a few difficulties in finding galaxies and globular clusters etc....

It could be that we cant focus on them because we stuggle to see the cloud forms on Jupiter. Given that we cant see the clouds on Jupiter are we flogging a dead horse when it comes to seeing galaxies? Part of the problem is that we dont know how big each feature in the sky should appear in the eyepiece. We have been concentrating on M66 and M65.

My question is to do with true field of view and the eyepieces used. Please could someone tell me if I have my numbers right!

M66

Apparent dimensions are 9.1' x 4.2'

So we have a 1000mm focal length scope. Using an eyepiece of 21mm with an apparent field of view of 40 degrees.

magnification = 1000mm / 21mm = 48x

true FOV = apparent FOV / magnification

= 40 / 48 = 0.8 degrees.

So just enough to get the moon in the field of view. But the dimensions of M66 are in minutes.

Im confused because with declination 1 degree = 60mins but with RA 15 degrees is 60mins. Are the dimensions of M66 given as 1 degree = 60mins?

If so, on our set up should M66 fill approx 1/5 of the field of view. ie 0.8 degrees true FOV x 60mins = 48 mins field of view and M66 is 9.1 mins long?

Sorry for the elementary questions!

We are finding the galaxies around the plough a bit high in the sky to view.... can anyone suggest a decent galaxy or globular cluster we can go for. We think we did have M66 and M65 last night but they just looked like a couple of specs of blurred dust or dirty paw prints!

Many thanks for any help and sorry for the long winded post!

[Tribal-Wolf]

Jupiter is low in the sky now so seeing will only get worse. Light pollution maybe your problem, I'm having that issue at the moment.

[starguest]

A friend recently bought a Skywatcher 200p and we are having a few difficulties in finding galaxies and globular clusters etc....

It could be that we cant focus on them because we stuggle to see the cloud forms on Jupiter. Given that we cant see the clouds on Jupiter are we flogging a dead horse when it comes to seeing galaxies? Part of the problem is that we dont know how big each feature in the sky should appear in the eyepiece. We have been concentrating on M66 and M65.

We are finding the galaxies around the plough a bit high in the sky to view.... can anyone suggest a decent galaxy or globular cluster we can go for. We think we did have M66 and M65 last night but they just looked like a couple of specs of blurred dust or dirty paw prints!

That last description of 65/66 is correct. They are small and not as luminous as many others. I only got them last night in fact, in a proper dark sky. The M81/82 although overhead-ish are much easier even in more light polluted arenas but they are still amongst the "faint fuzzies" really for 200mm and less.