What have i got myself into

[scarecrow]

A few people at work are aware i am a keen astronomer as i have showed them a few of my pictures i have taken. I did mention to a couple i would bring my quick scope to put on the building roof to show off the moon and jupiter. Well word has gotten around and now there are about 25 people who are interested in taking a look. As there is so many im going to drive in with my goto as it will be a lot easier to use as i wont have to move the scope anywhere. As this is in London, jupiter and the moon are safe bets and i dont think i can go wrong with that and im sure everyone will be happy. My only worry is setting up my scope on the roof. Its only 5 floors but will i have trouble with polar aligning. Also i dont think polaris or any main star will be around to do a correct align so if i just aim it north and do the 2 star align should that be ok for tracking once i have jupiter in the eyepiece?.

[JimStan]

Sounds like you need to get together with a club and organize a "star party" ! It is great that you have aroused such interest with your fellow workers, but 25 is a big number to keep happy all at one time!

The roof may not be the best place for viewing, since rising air currents from the building are apt to ruin your "seeing", but for non-critical viewing it should be OK !

I would choose a time when the moon is 1st quarter or so, and a planet or two are high in the sky. The public is usually not all that thrilled with the "faint fuzzies", so concentrate on star clusters, planets, and of course the moon.

Why do you not think that "Polaris will be around" ? Are other buildings blocking your view of the north sky? Polaris is ALWAYS in the same spot in the sky, so it should not matter when you are looking for it. But, just plopping your scope down and aligned with magnetic north should be close enough for the short glance that most people are going to be satisfied with. Just be ready to make corrections to your aim occasionally.

Hope this helps, but my best advice is to arrange this with a willing club.

Jim S.

[scarecrow]

It will be a first time for all of them so im sure a few minutes of the moon and jupiter will have them more then happy. If i can add a couple of clusters as well then I think i will be getting a few requests on scope types lol. I love this hobby and even if i dont get any scope time myself i will enjoy getting others interested in it.

[scarecrow]

Talking about Polaris I was just not sure the central london sky will have it visible but i will check what is out when the clocks go forward.

[newman]

Polaris keeps in almost the same place all the time, at the North Celestial Pole. If it's not obstructed by a building - i.e. if it can be seen at any time from that location, it will be there. It doesn't matter what time of year it is or even if it's nighttime or not. Polaris will always be very near the Celestial North Pole even when you don't see it during the daytime. Imagine Polaris as the center of a giant dome that rotates around the planet - while the edges of the dome move around quite a bit the further off center they are, the points near the center are always in almost the same place. Of course in reality it's the planet that does the rotating, but I find this analogy helps a lot of people understand the concept of the way the "stars travel". Because it's very nearly at the center of the imaginary dome is pretty much the reason Polaris is used as a reference for polar alignment.

[Capricorn]

The approximate alignment should be OK as all you want to do is track the moon and Jupiter enough for people to see them.

I would suggest that you mention that the alignment is only approximate as someone is bound to comment that Moon/Jupiter isn't staying in the centre.

Also check the position a few times as you may as well centre it before it drifts out completely.

Avoid the higher magnifications - moon doesn't need it. as both will drift out quicker. For all you may be able to handle say 150x but start with say 80x for Jupiter. Just so it remains in view a bit longer. Again say why, people like to know why. It is really too small you can always increase the magnification.

If you align it magnetically then I think the compensation is about 5 degrees for magnetic North to true north - just roughly. So aim the scope about 5 deg right of magnetic north.

After that best of luck.

[jimmyjamjoejoe]

If you align it magnetically then I think the compensation is about 5 degrees for magnetic North to true north - just roughly. So aim the scope about 5 deg right of magnetic north.

Beat me to it

[carastro]

Yes what you are proposing is perfectly adequate for the type of event you have planned. I often get involved in public events showing Moon and Jupiter and Saturn and rarely bother to do an alignment at all on these occasions, I usually hop in and adjust after every 2nd person has looked. Does depend on how powerful your scope is of course.

It's great introducing the wider public to Astronomy and you might get some of them hooked.

Carole

[Skylook123]

There are two factors to be aware of when setting up on top of a building (or a balcony on a lower floor). Vibrations might periodically interfere with the view, and the thermal environment may also cause problems with the view.

But, you shall never know, unless you do it! Good luck with your adventure. The Moon and Jupiter are bright enough to find in most any location. Colorful double stars such as Albireo might be good to show as well. The Owl (NGC457) is one of the few targets that resemble its name, but it is a bit sensitive to contrast and may be lost in the urban light. Just go and have fun with it.