Lost when star hopping

[ianpwilliams]

I've just been into the back garden with my 200P Dob for the first time, and it's fair to say that I couldn't find much, apart from a hell of a lot of stars! I attempted to recognise some constellations, using Stellarium on my Android phone. I managed to find Ursa Major, and then a few others, and I eventually spent ages trying to find Pegasus, so that I could go to the left to Mirach, and then up to the Andromeda Galaxy. But I had two issues:

A - I couldn't tell how wide field my scope and finderscope FOV's were, and

B - both scopes showed a lot more stars than were visible with the naked eye

This meant that I was constantly getting lost when trying to star hop. "Turn Left at Orion" is in the post, but even with that I'm sure I'll struggle!

Can anyone offer any advice?

[Tinker1947]

I use a Telrad you can look with both eyes, i found the finder scope pretty useless as there were more stars than i could see and they all seemed the same brightness......lining up the Telrad is quite easy,daytime a distant spire, night time do it early at dusk so the brighter stars are only showing....

[avtaram]

+1 for the Telrad, makes star hopping easy.

Avtar

[Digger1895]

There's nothing like learning your skies, but, as an alternative because you have a Dob you could try setting circles for locating objects. I've built some really rough ones which when used with an inclinometer one my phone work really well. I say they are rough because I just printed them out and blue tacked them on to see how they work, but as they work so well I'm afraid to take them off!

[Charic]

Keep both eyes open when using the standard  finderscope. It may sound strange, but with both eyes open, the brain matches the image from each eye,  left eye focusing on the 'real' star and the right eye looking through the finder.  Both images should align when on target,  makes star hopping a little easier, that is, when you get used to the orientation of the real stars to that viewed through the scopes. A Telrad could help, but the reach (my telrad is far side of the finder scope) is awkward for some folk, without cuddling the telescope from a seated position?

Remember, the reason for getting such a big aperture was to see more? the scope is about 1100 times the surface area of your pupil. You just gotta take your time,  also  maybe start with a wider angle EP. The 32mm Panaview is my choice. I was able to get M31 in view tonight, almost  edge to edge. If it had been just a little bit darker, I may have needed a wider EP!

[ianpwilliams]

I did consider buying a star atlas (most likely the pocket one), although I don't know if that would be worth buying as well as "Turn Left at Orion". But then the issue isn't with finding target areas with the naked eye, more with reaching them through the scope. Would it be worth buying a sky atlas anyway?

I also considered buying a diagonal for the finderscope because it's a pain leaning over every time, although that would eliminate the possibility of keeping both eyes open. Also I have to wear glasses to see the stars in the sky with the naked eye, so I try to keep my glasses on if I can when looking through the scopes, otherwise it's annoying taking them off and on again.

[Charic]

Taking  glasses on and off was an issue with my Telrad? I've since re-purchased a Telrad, but the reach is still distant. I may try a  DIY riser to install it nearside of the finder scope. but if its too much trouble, I may sell it on again? Its one of those gadgets that just feels it should be there, however, I really need to wear my glasses to get the best from mine.

Any book  or Star chart is a worthwhile investment for when you're away from the abilities of a computer or Wi-Fi connection, although reading a book at your viewing site means the site is not dark enough?  Stellarium is my astro program of choice, I look at what's up, then go out and look, checking when I get back in. I generally just look at one constellation a night. You can create and print ANY chart from Stellarium.

I dont think you can just buy a diagonal for the 9x50. You have to get a complete replacement, but alone, the 9x50 is ok. maybe a partner could use the finderscope. 

Getting used to the scope helps. I often look at Ursa major,  it being so large and spread out, giving me  acres of space for  Star hopping practice,  just using the telescope at  either 8mm 12mm or  32 mm

[ianpwilliams]

What do you mean when you talk about setting circles? I'm completely new to this so I don't know.

Is it to do with this star hopping guide, which suggests drawing rings onto star charts in order to calculate the field of view?

http://www.nightskyinfo.com/star-hopping/

If I could do that then maybe I could get an idea of what my finderscope and wide-angle eyepieces are showing me?

In which case I would need to know the fields of view of my 9x50 finderscope and my 10mm and 25mm eyepieces on my 200P (any help with that would be appreciated), and then maybe I could print a star chart from online (or maybe from Stellarium) and draw circles on that?

One of my neighbours came out into the garden while I was out there, asking if he could have a look, and I had the pleasure of being able to show him "a star". But on the plus side I did see a very brief shooting star.

[happy-kat]

The other thing is the view through the telescope is inverted and this causes me some confusion relating what I see by eye to what I see in the eye piece

[happy-kat]

Stellarium u using occular view is very helpful

[Digger1895]

What I meant by setting circles is basically a circle marked off in degrees to 360 and placed around the base of your Dob to give azimuth co-ordinates. I try to align mine to the SCP as I'm in Australia (North for you in the northern hemisphere), then correct the alignment with a known point like a star. You use the inclinometer to get the altitude reference point.

Any app will give you the co-ordinates in both ra/dec and alt/az which changes with time.

[Digger1895]

You then use these co-ordinates on your setting circles and inclinometer to "goto" or rather "pushto" the object you want to view.

[ronl]

I use a Rigal Quickfinder, and I must say it makes such a difference finding

targets, it's very light, so doesn't interfere much with the balance of the scope,

you set it up with your scope and finder scope, which is very easy, then you

keep both eyes open, which helps when star hopping, once you are near or

close to the target, you look through the finder scope, if you are close enough

you should see your target, once you get used to it, it makes it so easy, I have

never had a Telrad, but I should think it works the same way.

If you're quick there is a Telrad for sale in the classifieds on the home page.

[phoobar]

Hi Ian

I would learn the constellations with the naked eye first so every time you go to your garden you can quickly go through the common constellations that you see. As you only get to see a few at certain times of the year and only in darkness they are very easy to remember and locate. Stallarium is perfect nothing else is needed other than practise and patients.

I am facing east and work off of cassiopeia, if I can find that everything else is easy now.

Also make sure your finder scope is properly aligned with your eyepiece view, this was a problem for me until I fixed it and was having the same problem.

I also have the 200P and the finder scope works well for me, but I am considering purchasing a non expensive 32mm wide fov eyepiece, just for star hoping.

Tonight should hopefully have some clear skies

[Qualia]

A - I couldn't tell how wide field my scope and finderscope FOV's were, and

B - both scopes showed a lot more stars than were visible with the naked eye

I was constantly getting lost when trying to star hop.

Can anyone offer any advice?

With reference to A:

Field of View: Eyepiece's field of view divided by the Magnification of said eyepiece. For example: 1000mm focal length scope divided by 10mm eyepiece = 100x. The eyepiece is a 50º Plossl. Therefore, 50 divided by 100 = 0.5º True Field of View. According to specific specifications, most of the more popular finder scopes over between 5.5º to 6º of True Field of View.

With reference to B:

Check out: this and this.

If you need anymore help, please don't hesitate in asking

[Moonshane]

Would you set off to an unknown town without a map or Satnav ? A star map is essential as in my opinion is a red dot finder of some kind, a dim red torch and a right angle correct image finder. With these you will locate anything within the reach of your scope and sky quality

[ianpwilliams]

The finderscope is properly aligned, so no issues there.

FLO don't have any Telrads (couldn't see one in classifieds either, but they do have Quikfinders.

I like the idea of a setting circle, not sure of the best way to make one though. And I do have a compass app on my iPod with an inclinometer, so I'll use Stellarium on my phone, and have my iPod running the inclinometer. At least then I can get the elevation right.

I also think I'll order the pocket star atlas, and hopefully I can find some online star maps to print in the meantime.

[Tinker1947]

Telrad maps are free, just Google "Telrad maps".....

[Ptarmigan]

I also think I'll order the pocket star atlas, and hopefully I can find some online star maps to print in the meantime.

It just happens that I was organising my folder of freebie charts,

so before you go spending too much, have a browse through these links :

Toshimi Taki

http://www.geocities.jp/toshimi_taki/

http://www.geocities.jp/toshimi_taki/atlas/atlas.htm

http://www.geocities.jp/toshimi_taki/atlas_85/atlas_85.htm

DSW

http://www.deepskywatch.com/deepsky-atlas.html

A4, less detail - http://www.deepskywatch.com/deepsky-atlas-release1.html

A3, more detail - http://www.deepskywatch.com/deep-sky-hunter-atlas.html

Cloudynights - The Mag-7 Star Atlas Project

A set of pdf charts in B&W or colour

http://www.cloudynights.com/page/articles/cat/articles/observing-skills/free-mag-7-star-charts-r1021

"all" pdf

http://www.archive.org/details/Mag_7_Star_Atlas

TriAtlas

in various formats and magnitude limits- A,B,C,B-C and PanoramicB

http://www.uv.es/jrtorres/triatlas.html

To make your own charts, at your own scale and depth, try Cartes du Ciel excellent prog but beware a steep learning curve  !

TUBA - Touring the Universe Through Binoculars Atlas

can be used to print simpler brighter stuff

http://www.philharrington.net/tuba.htm

[Ptarmigan]

Forgot the link to "Cartes du Ciel"

http://www.ap-i.net/skychart/en/start

That one will keep you going through many a long cloudy night - dreaming great obs.  :)

Good luck.

[ianpwilliams]

Wow thanks, lots of options there!

[Ptarmigan]

lots for you to play with.

I was not sure if I should include them all at this stage,

dont want you to be 'lost in charts' as well as 'lost when star hopping' !

But I am sure you will be able to pick your way through them and they are all in one place

I would maybe suggest start with Taki 6.5 or TUBA

Another thing that I have thought of - at this time of year pointing a scope into the sky stands a good chance of pointing at the most dense regions of the milky way = overwhelming numbers of stars ! So how is your view to the north ?

That way you can find easily ( I mean slightly more easy !!) recognisable constellations like Ursa Major, aka The Plough, and the W of Cassiopea, so maybe start off over there ?

Oh yes, you already found U.Maj So , ,

the last but one star in the tail of U. Maj. is easily found and is a good practice double (multiple) star to get the feel/orientation of your scope. Wont be mistaken for other stars close by. The two principle stars (Mizar and Alcor) are even seperable unaided eye ( good-ish young eyes ) so that way you can see what is upside down in your scope and which way to move it, field of view in various eyepieces  etc. to get to other stars in U.Maj.

Good luck,

hope the clouds soon move for you

[ianpwilliams]

Thanks, and yes, Ursa Major is the only one I recognise every time, although I'm sure more will follow eventually.

[ronl]

Here is a link to free star charts http://freestarcharts.com/index.php/messier-catalogue you can

print them off and then laminate them, otherwise they go soggy when the dew gets on them,

sorry the telrad was in the wanted, but not shown as wanted.

[ianpwilliams]

Thanks, I'll give that a try to.

I'm eager to get out there again, because after last night's disappointment (which I am fully aware was my fault), I'll admit that there was a brief moment where I thought I may have made the wrong scope choice, and considered returning it. The other choice was to get the ED80 Pro Outfit for my HEQ5 mount to go down the imaging route instead, and yes I know that that would be even more challenging, but I believe that the ED80 would eventually result in photos (of hopefully increasing quality), whereas the 200P may just result in small blob galaxies. But then I did eventually decide that I would go for both the 200P (for visual sessions) and the ED80 (for imaging sessions), so if I could get results with the Dob and justify buying it then that would be great. And I would be reluctant to return it to FLO anyway when they are so helpful, and when I'm intending on buying a fair bit more from them. Not having a car also makes things frustrating, because I bet this thing would be amazing away from the city.

When it comes to star hopping, it did occur to me that maybe I should try to find a galaxy that's near a constellation I know (ie Ursa Major), and then I might have a better chance of finding it. And I noticed that the Pinwheel Galaxy seems to be just above two of the stars of Ursa Major according to Stellarium (with Pinwheel making a triangle), so maybe I should look for that first?

It's all irrelevant tonight anyway, because the weather has gone from clear to cloudy. Just goes to show that you can't trust the weather forecast!