24.5 observing 11pm - 1am

[Guest Justin]

I waited until 11pm before observing then centered the scope on Arcturus, corrected RA and adjusted setting circles for M3, which I found without much trouble, although not seeing any individual star detail of the cluster. Now the scope had cooled down I found Saturn with the finder scope and upped magnification from 50x to 375x, Titan was plain (above and left) and Dione (mag 10.5) was just visible to the left of Saturn but with averted vision.
Then to Const. Coma Berenices and star Diadem. It was a simple star hop to see M53. After this I went to Const. Ophiuchus and the star Raselhague then used the setting circles for M12 but I was unable to see the cluster, so I went on to nearby open clusters.
IC4665 - very uniform spread and magnitude of stars
NGC 6663 - a vein of stars
IC 4756 - very faint
Onto Vega, I corrrected RA for the zero magnitude star, adjusted setting circles for 6 Lyra centered star in the scope and adjusted setting circles for 12 Lyra. This being the target, with noiceable colours and almost an open cluster in itself.
Finally to Const. Serpens and the star Unukalhai, corrected RA and adjusted setting circles for M5, placing the scope almost exactly on the target.
For most of the night I could use planetarium software but regarding Ophiuchus and not being familiar with the constellation I got the phone out and used Google.stars to identify raselhague.
By now it was 1am so I called it a day.

[dawson]

Nice report. Sounds like a rewarding evening.

Where were you viewing from, was there much light pollution?

Jd

[Tweedledee]

Very nice report Justin. I like those clusters.

 

What equipment were you using?

[Daz Type-R]

Nice report there.

Quick question, why do you have to keep correcting RA?

[Guest Justin]

I am observing from Nottingham just by the river so regretably fairly significant light polution. South and overhead sky is the least affected. I am using a Celestron 127 EQ which is a 'Bird Jones' scope with 127mm mirror and 50cm focal length F4. however a 2x Barlow is incorporated into the focal tube making it F8. Very much a beginners 'scope.
When I 'adjust' Right Ascension it is because this is a manual telecope and if I locate an object it has its coordinates (Hrs Mins + Degs) and I will set the hours ring on the equatorial mount to the stellar coordinate. If I view this object for 10 minutes I will have slewed the scope several times to counteract sky rotation and the RA ring will no longer be right. You people with full electronic control don't have to worry about this.

[Daz Type-R]

I too have to find things myself as I own a dobsonion telescope. I use a Wixey and a setting circle on my dobs base, once it is set for the night, it is set, I don't have to alter it unless I catch the setting circle. I just wondered why you had to keep adjusting yours.

[Guest Justin]

Oh yeah I see what you mean. With an Equatorial mount the Right Ascension dial is exactly aligned with zero degrees declination and at our latitudes has a 38 degree tilt. Suppose I adjust it for Spica at 10pm and it is directly South (13h25m -11deg), after 1 hour, sky rotation will place Spica 15 degrees west. If I followed Spica my RA dial would now read 12h25m so by this time it is wrong and now needs correcting. This is really easy, I just loosen the RA knob and rotate the dial clockwise as is meant, to 13hr25min. Since it is 11pm and Spica has moved but its stellar coordinate is the same. I suppose I needn't state how I centre a nearby star before using setting circles to locate final object but thats how I do it during the course of an evening, and the star must be properly identified before I go further. Even relatively expensive scopes have non-driven EQ mounts such as the Skywatcher150, which is a super piece of kit but so many beginners never get the hang of the EQ mount and do stuff like use the Polar Alignment axis for star tracking.