coutleef
scholastic sledgehammer
Reged: 02/21/08
Posts: 806
Loc: Montreal and St-Donat, Québec,...
|
|
OK, don't laugh at me.
I have been trying to nail that cluster for the last two nights. I have seen most of the clusters in Cassiopea, several globulars in the summer sky but it seems that i can just not see this one.
It is really easy to find it on charts in the Sagitta. I at first thought it would be an easy target. I can not see the arrow in my light polluted sky but i see it clearly in my finder.Looked betweeen gamma and delta and carefully looked at my star atlas 2000 to be sure i was in the good area.
I will try at my dark site, but is M71 easy from the city?
Is there something i am missing?
--------------------
François
Nexstar 8 SE
50mm StellarVue finderscope, Astronomik UHC-E and Orion OIII filters
WO Swan 40mm; TV Pan 22mm; TV Nagler 9T6, 12T4, 17T4; TV Plossl 11mm and 15mm.
WO 2" dielectric diagonal retrofitted with Denk Power Switch (and now reach the zenith with the shorty adapter).
|
smasraum
sage
Reged: 01/13/08
Posts: 492
|
|
I'm in a suburb of Houston. I never dark adapt in my driveway because of a street light. Normally, I can see mag 4.5 stars naked eye. I used this chart and binoculars to familiarize myself with that part of the sky, and then my 9x50 RACI to get close. I was able to see M71 pretty easily. I suspect you should be able to see it unless you have really bad skies.
--------------------
Steve
Houston (Friendswood), TX
 Space Center Houston
8" Zhumell Dob - Woo Hoo!!
Celestron C102 f/5 - Thanks Tim!
21mm, 13mm Hyperion
2.5x TV Powermate
Canon Rebel XT
Nikon 7x35
Bushnell 10x50
Edited by smasraum (09/19/08 09:14 AM)
|
EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12515
Loc: Cumberland, R I , USA42N71.4W
|
|
Often elusive. Best tried at lower powers. Skies make a big difference. At mag 5 skies, it's seen in 10x50s and 25x100s. At mag 4 skies it's not seen at all in anything. In scopes, try using 2-3mm exit pupils.
edz
--------------------
Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
|
Achernar
Post Laureate
Reged: 02/25/06
Posts: 3690
Loc: Alabama, USA
|
|
I see this open cluster from my front yard all the time whenever it is high in the sky and the sky isn't hazy. It's an easy object and from a dark site you can see it fully resolved into a dense clump of stars. It appears you were looking in the wrong place rather than your sky conditions being too poor to see it.
Taras
--------------------
10-inch F/4.5 Discovery Dob
6-inch F/8 Homebuilt Dob
4 1/4-inch F/4 Homebuilt reflector
|
stefanj
Pooh-Bah
Reged: 11/15/07
Posts: 1287
Loc: Western New York State
|
|
Elusive enough- that I can only get it with my 10" dob.
--------------------
Life is a circus- and I'm stuck in the FREAK TENT
If these are blue- it means the moon is full!
Meade ETX 90RA w/ tripod
Meade AZ 70
Meade DS 2130 AT
Zhumell 10" Dob
Zhumell Plossel EP and Filter set
Simmons 10x50 Binoculars
GLPx6
LPI
|
coutleef
scholastic sledgehammer
Reged: 02/21/08
Posts: 806
Loc: Montreal and St-Donat, Québec,...
|
|
The least i can say is that we have obtained diverging opinions about this cluster.
In fact i think that my sky conditions were not that great as there is quite some LP in the area where M71 now stands and it was not high in my sky.
As to looking at the right place, once you have the arrow in the finder, it is quite difficult not to look at the right place.
Opinions were divergent, leading me to think that sky conditions are of outmost importance to see that DSO. The best test will be to find it at my dark site and then i will know where it stands and i'll try it back again from the city.
--------------------
François
Nexstar 8 SE
50mm StellarVue finderscope, Astronomik UHC-E and Orion OIII filters
WO Swan 40mm; TV Pan 22mm; TV Nagler 9T6, 12T4, 17T4; TV Plossl 11mm and 15mm.
WO 2" dielectric diagonal retrofitted with Denk Power Switch (and now reach the zenith with the shorty adapter).
|
Tony Flanders
Carpal Tunnel
Reged: 05/18/06
Posts: 2062
Loc: Cambridge, MA, USA
|
|
I would describe it as medium-difficult. Much easier to see than most galaxies, but definitely harder than average for a Messier globular. Certainly not as hard as M72. Keep at it; you should be able to do it! And once detected, it's probably the easiest of all Messier globulars to resolve.
Take a look at the description on my website.
--------------------
Tony Flanders
eyeglasses
6x15 and 8x32 monoculars
8x25, 7x35, 10x30 IS, 10x50, and 15x70 binoculars
70mm and 100mm achromatic refractors
4.5", 7", and 12.5" Dobs
|
Tony Flanders
Carpal Tunnel
Reged: 05/18/06
Posts: 2062
Loc: Cambridge, MA, USA
|
|
Quote:
The least i can say is that we have obtained diverging opinions about this cluster.
Right. Isn't it funny the way most people assume that their own backyard is the norm, and that anybody else's sky conditions must be some kind of aberration? As in "M33 is an extremely elusive object" or "if you can't see M33, there must be something wrong with your eyes." Both statements are perfectly accurate, depending on your sky conditions.
Like all deep-sky objects, M71 is tremendously sensitive to light pollution. And that's more true of this particular globular cluster than most Messier globulars. Though it's nowhere near as sensitive to light pollution as (say) NGC 5053 or most galaxies.
Under dark skies, all of the Messier objects are readily visible to experienced observers through a 60-mm scope and utterly impossible for even rank beginners to miss through an 8-inch scope.
In the middle of a big city, only 20-30 Messier objects are genuinely obvious through an 8-inch scope.
--------------------
Tony Flanders
eyeglasses
6x15 and 8x32 monoculars
8x25, 7x35, 10x30 IS, 10x50, and 15x70 binoculars
70mm and 100mm achromatic refractors
4.5", 7", and 12.5" Dobs
|
WadeVC
Carpal Tunnel
Reged: 12/02/05
Posts: 2779
Loc: Lodi, California,
|
|
There are a lot of variables in regards to how elusive M71 may be. I notice that you have a Nexstar 8 SE, so the scope is very capable (I have seen M71 in my wifes 8" and even my old 6" Dob), so your scope isn't the issue.
Your skies, however, will play a bigger issue in locating M71. Dark skies are indeed required to catch a glimpse of this Globular as, unlike the majority of GC's, M71 is fairly dim and quite small. This GC is a typical "fuzzy" in low magnification EP's, and even at modest powers, you won;t get too many stars to resolve. You can indeed tell that it is a GC, but do not expect an explosion of stars like you can see with M13 or M15.
I have attached a digital sketch of mine showing how it appeared in my EP using a 10" Dob. in dark skies; hope it helps.
--------------------
Orion XTi10 f/4.7
Orion XTi8 f/5.9
Meade NGC 70mm f/10
Orion UltraView 10x50 Wide-Angle Binoculars
My Sketch Gallery
My Astronomy Blog
A wise man can see more from the bottom of a well than a fool can from a mountain top.
|
coutleef
scholastic sledgehammer
Reged: 02/21/08
Posts: 806
Loc: Montreal and St-Donat, Québec,...
|
|
Thanks a lot,
very helpful that you mentionned that you were using 120x to obtain this view. I looked for it at max 80x to find it.
Will help me tremendously when i'll try to find it next time. I was looking for something fuzzy but bigger than what you sketch.
Francois
--------------------
François
Nexstar 8 SE
50mm StellarVue finderscope, Astronomik UHC-E and Orion OIII filters
WO Swan 40mm; TV Pan 22mm; TV Nagler 9T6, 12T4, 17T4; TV Plossl 11mm and 15mm.
WO 2" dielectric diagonal retrofitted with Denk Power Switch (and now reach the zenith with the shorty adapter).
Edited by coutleef (09/19/08 03:35 PM)
|
smasraum
sage
Reged: 01/13/08
Posts: 492
|
|
I think I initially used 57x to find it and then zoomed in from there.
--------------------
Steve
Houston (Friendswood), TX
Space Center Houston
8" Zhumell Dob - Woo Hoo!!
Celestron C102 f/5 - Thanks Tim!
21mm, 13mm Hyperion
2.5x TV Powermate
Canon Rebel XT
Nikon 7x35
Bushnell 10x50
|
EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12515
Loc: Cumberland, R I , USA42N71.4W
|
|
Quote:
I was looking for something fuzzy but bigger than what you sketch.
Actually, I see it fuzzier and bigger than that sketch when viewed in 20x80 and 25x100 binoculars. M71 has very little concentration. At 80x-100x even in a midsized scope, it becomes difficult to see concentration and resolved cluster stars begin to mix with background stars. This is one cluster that I think is better seen at lower powers, just so you do get some concentration into the globular form.
Quote:
I can not see the arrow in my light polluted sky but i see it clearly in my finder.
The two tail feather stars of Sagitta are both mag 4.4, so your skies are not very dark.
edz
--------------------
Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
Edited by EdZ (09/19/08 04:40 PM)
|
MikeRatcliff
Pooh-Bah
Reged: 06/12/04
Posts: 1105
Loc: Redlands, CA
|
|
A historical side note: Astronomers for a long time were not sure whether M71 was a globular cluster or a large open cluster.
For us, that means that the core is not very bright. It is a softer cluster compared to most other Messier globulars, as others here have said.
I'm sure you'll find it soon.
Mike
--------------------
16" f/4.9 dob
Tele Vue Plossls 32,25,20,15,11
13 Nagler T6
10.5 Pentax XL
Brandon 32, 16
12.5 UO ortho, 9 Circle T ortho
2x TV Barlow
|
coutleef
scholastic sledgehammer
Reged: 02/21/08
Posts: 806
Loc: Montreal and St-Donat, Québec,...
|
|
unfortunately, you are right on that.
I live in Montreal, and although it is a small city (compared to New york or other big cities) it generates as much light pollution as New york. I think we have always seen electricity as a resource we had abundance of and 'illuminate' our surroundings at night quite intensively (and often completely uselessly).
So i live in a white region in terms of LP.
But my dark site is in a green zone. I bet i will have no problem there!
--------------------
François
Nexstar 8 SE
50mm StellarVue finderscope, Astronomik UHC-E and Orion OIII filters
WO Swan 40mm; TV Pan 22mm; TV Nagler 9T6, 12T4, 17T4; TV Plossl 11mm and 15mm.
WO 2" dielectric diagonal retrofitted with Denk Power Switch (and now reach the zenith with the shorty adapter).
|
EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12515
Loc: Cumberland, R I , USA42N71.4W
|
|
Looking at M71 early tonight, in my 8" SCT with a 32mm pl at 65x, it is already partially resolved with numerous stars blending it into the stellar background. It doesn't look much like a globular at all, is quite spread with faint stars, with very little or no nucleus. The brightest of a nearby 3 star string is just on the edge preceeding with M71 about 20-25 arcmin east near the center of the fov. Sky is perhaps mag 4.7-4.9
edz
--------------------
Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
|
setldown
member
Reged: 05/07/07
Posts: 94
Loc: N42° 33' - W87° 52'
|
|
After a long day out goofing....ahem golfing, I really didn't plan to roll the scope out tonight. Then I started reading this and thought "Gee I don't know if I ever nailed M71." So out comes the scope and Polaris was just visible at twilight. I aligned the 8se on Polaris and Arcturus and commanded it to goto M71.
"Mmmm" I don't really see it, so I sync the scope on Altair as insurance and command it to find M71 again.
I'm studying the FOV and see a small group of faint stars at about the 10 o'clock position and another little group at the 4 o'clock position at 98x. Still nothing obvious.
Then as darkness starts to take over I spot a faint gaseous type smudge right smack between the groups of faint stars. Sure that I've found M71 I crank up the magnification to 142x and start concentrating on it.
Then in short order at approx. 8:05 CDT three satelites zoom through the FOV and right smack through the center of M71 within seconds of each other. Cool reward!
My urban site is smack in between Chicago and Milwaukee with a street light right in front of my house so you can spot it from a moderatley light polluted area.
Thanks Francois for the motivation. 
Rick
--------------------
Rick
Celestron 8SE w/ Bob's Knobs
Stellarvue SV-F50B2 9 x 50 RACI
WO 2" Quartz Dielectric Diagonal / WO Binoviewer
Jasper Always GLP
JMI Motofocus - MFNEX6
TV Panoptic 35mm - 27mm - 19mm - 2X Powermate
Nagler 13mm T6 - 9mm T1 - Baader 8x24 Zoom
Canon 450d - Nikon Coolpix 4500 - SPC900nc
Location: Dark Side of the Moon
|
setldown
member
Reged: 05/07/07
Posts: 94
Loc: N42° 33' - W87° 52'
|
|
As an update to my last post, once the Moon came out the view of M71 changed dramatically as expected. Although the moon is waning, it is still 75 to 80% lit. Even though I knew exactly where M71 was it became a whole different beast to spot.
The moon along with strong light pollution will make locating and identifying this target a real challenge. 
--------------------
Rick
Celestron 8SE w/ Bob's Knobs
Stellarvue SV-F50B2 9 x 50 RACI
WO 2" Quartz Dielectric Diagonal / WO Binoviewer
Jasper Always GLP
JMI Motofocus - MFNEX6
TV Panoptic 35mm - 27mm - 19mm - 2X Powermate
Nagler 13mm T6 - 9mm T1 - Baader 8x24 Zoom
Canon 450d - Nikon Coolpix 4500 - SPC900nc
Location: Dark Side of the Moon
|
David Knisely
Postmaster
Reged: 04/19/04
Posts: 6760
Loc: Beatrice, Nebraska
|
|
Quote:
OK, don't laugh at me.
I have been trying to nail that cluster for the last two nights. I have seen most of the clusters in Cassiopea, several globulars in the summer sky but it seems that i can just not see this one.
It is really easy to find it on charts in the Sagitta. I at first thought it would be an easy target. I can not see the arrow in my light polluted sky but i see it clearly in my finder.Looked betweeen gamma and delta and carefully looked at my star atlas 2000 to be sure i was in the good area.
I will try at my dark site, but is M71 easy from the city?
Is there something i am missing?
Well, it is not exactly easy, but it is possible. I put my 100mm f/6 refractor on it tonight (ZLM 4.6, moon in the sky), and did manage to see its small diffuse glow at 25x. At 76x, it stood out just a tad better and looked a little irregular or patchy, although it still remained mainly a dim glow rather than something bright. Under a dark sky, it is fairly easy, but with skyglow, it can be a little hard to pick out. Clear skies to you.
--------------------
David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
|
coutleef
scholastic sledgehammer
Reged: 02/21/08
Posts: 806
Loc: Montreal and St-Donat, Québec,...
|
|
Thank you all for your advice and encouragment.
I never thougth i would receive so many answers for a simple question. I'll give it another try this sunday (clear skies then) and i think i will try my precise go to feature.
I forgot to say that the moon was up so as said above that may be another factor.
So much more interesting to have this discussion than another discussion on the Ethos or some other EPs
Thanks
--------------------
François
Nexstar 8 SE
50mm StellarVue finderscope, Astronomik UHC-E and Orion OIII filters
WO Swan 40mm; TV Pan 22mm; TV Nagler 9T6, 12T4, 17T4; TV Plossl 11mm and 15mm.
WO 2" dielectric diagonal retrofitted with Denk Power Switch (and now reach the zenith with the shorty adapter).
Edited by coutleef (09/20/08 09:37 AM)
|
coutleef
scholastic sledgehammer
Reged: 02/21/08
Posts: 806
Loc: Montreal and St-Donat, Québec,...
|
|
Got back to finding M71 yesterday evening. Great evening with transparancy above normal and no cloud.
No moon also. In retrospect i was looking at the right place but just could not see it.
Three factors were involved now that i have seen (i still consider it is not an easy target)
1) the moon was getting up and that made a huge difference of looking without moon yesterday. The area was washed out with the moon and now was much darker and i swa the cluster
2) LP
3) my attention was drawn from time to time to a skunk that was walking nearby my site. She is becoming more and more used to having me in her neighbourhood when she walks on our lawn in the evening. But i am still cautious with this animal although more and more we seem to live without bothering each other. Lets say that my attention was not entirely focused on the stars that night.
Thanks for your advice
--------------------
François
Nexstar 8 SE
50mm StellarVue finderscope, Astronomik UHC-E and Orion OIII filters
WO Swan 40mm; TV Pan 22mm; TV Nagler 9T6, 12T4, 17T4; TV Plossl 11mm and 15mm.
WO 2" dielectric diagonal retrofitted with Denk Power Switch (and now reach the zenith with the shorty adapter).
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
