EdZ
Professor EdZ
Reged: 02/15/02
Posts: 11725
Loc: Cumberland, R I , USA42N71.4W
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Some information about the population of stars in M44 gives a very good indication of magnitude ranges. The 25 brightest stars all range between mag 6.3 to mag 8.0. M44 has 80 stars to mag 10.0 and has 100 stars to mag 10.9. My chart (see link) has just over 200 stars plotted, 140+ stars plotted within the boundary and 60 more within the 2° square periphery. I can see every star on this chart (plus more) when tested with my 5" scope that has a measured LM of 13.1, so this chart reaches to about mag 13.
Follow this for a link to the M44 Chart
On the west there is a very distinct N-S line of 5 bright stars (in a 8x40 it's 4 bright and 1 dim), running from top to bottom of the cluster. On the south there is a distinct string of mostly bright stars just outside the true boundary that I use as my defining limits. On the left (the east) there is a very noticable barren area that helps clearly define that edge. These recent observations overlooked 4-6 stars on the extreme periphery that were included in early observations.
Previously, With various binoculars I have seen
56 stars using Pentax PCF WP 10x50 sky5.2
67 stars using Fujinon 10x70 sky5.2
72 stars using Nikon Superior E 12x50 sky5.2
70 stars using Orion Minigiant 15x63 sky5.0
80 stars using Oberwerk 15x70 sky5.0
Under mag 5.0 skies, the Oberwerk 15x70 just reaches the limit of mag10 stars.
Here are results from recent observations over a two night period. Both nights were about mag 4.9.
42 stars - Captain's Helmsman 7x50
41 stars - William Optic 7x50
39 stars - Oberwerk Mariner 7x50
39 stars - Captain's Storm King (old single coated Swift) 7x50
40 stars - Bushnell Legend 8x42 roof
40 stars - Nikon AE 8x40
48 stars - Nikon AE 10x50
51 stars - Nikon AE 12x50
If I were to hazard a guess, I'd say 40 stars is mag 9 and 50 stars is about mag 9.6 to 9.8. In all cases, each of these binoculars saw just a few stars on the limit borderline needing averted vision.
Several other observations.
M81-M82 were both seen in all binoculars. In the AE 12x50, AE10x50, WO7x50 and CN7x50, both were fairly bright and some shape and orientation could be seen (elongated axis). The AE8x40, BL8x42, OM7x50 and CSK7x50, could not see these bright enough to say any more than both spots were seen.
Only one member of the M65-M66 pair was seen, and only in the AE12x50, AE10x50, WO7x50 and CN7x50, and in all cases just barely seen.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Randy Cordell
super member
Reged: 09/16/07
Posts: 196
Loc: Cedar Rapids IA
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Hi Ed. This post prompted me to go out and examine M44 last night with my 7x50M's. I've never spent any time looking at it. I was trying to count stars hand held and it was immediately evidient to me that I didn't know how large an area is considered part of M44. I saw the chart through the link above and then through the link found there. It still looks like there are many stars that are borderline and just outside of the circle. I guess that is why you suggest printing it and then circling all the stars you can see. This can be pretty challenging I assume in figuring out which of the stars on the chart are in the eyepiece but it sounds like a fun challenge. It's also very interesting to attempt to determine the magnitude the instrument can resolve. The number of stars that can be counted can be somewhat subjective (depending on where a person defines the line of the circle lands) but the magnitude of the stars that are visible is less so. Would you count everything visible with averted vision? I seem to have pretty bad direct vision for all except the brightest objects so i use this a lot.
Thanks for an interesting (and yet again, exhaustive) post.
May the day-time nourishing rain always clear for night-time viewing!
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Randy Cordell
Meade StarFinder 10" F/4.7 Dob, Telrad, Craford, Fans
Bogen 3040 and 3050 Tripods with Orion Paragon-Plus Parallelogram or 3047 head
Oberwerk Mariner 7x50
Pentax PCF WP 8x40
Garrett Optical Gemini 15x70 WP-IF
Laptop running Kubuntu and Stellarium 0.9.1
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 11725
Loc: Cumberland, R I , USA42N71.4W
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Quote:
Would you count everything visible with averted vision?
Always. The limits of every binocular are always found in what can be seen with averted vision. If you don't test to the averted limit, you are never finding the limit. You might see stars at the limit of magnitude reach for only 5-10 seconds out of each minute you look at the spot.
I have two other charts, one for Cr399 and one for M45, that I originally developed just for doing star counts. later, both charts were detailed with the magnitude of all the individual stars on the chart. I haven't yet developed my M44 chart that far. But I know from experience and from research what some of the counts represent.
Once you've used a chart and get to know the patterns, star counts are easy. I know this chart so well, having used it so many times, that I can draw a sketch of about 70-80 stars in M44 from memory. I could put another 30-40 on the chart to show the dense areas, but they wouldn't be accurately placed. I'd say it takes me no more than 2-3 minutes to count 40-50 stars in any 7x50 - 10x50. But I could spend another 5 minutes more to scan around with averted vision to see if any stars more pop into view. So the first 40-50 take 2 minutes, the last 2 or 3 take 5 minutes.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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ronharper
scholastic sledgehammer
Reged: 02/14/06
Posts: 790
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Ed,
Don't think we don't appreciate this study, just because we are rendered speechless and dumbfounded. This sounds like a real observing challenge, which would improve anybody's skills. I would guess the final few stars would depend as much on who, as through what. I am trying to muster up the necessary retinal energy for this one. Thanks especially for getting down to the nitty-gritty of how you do this.
Personal differences and challenges aside, it is a wonderful real-life way to compare binoculars. It sounds like hard work to us typical lazy bums, but I trust that for you it was fun.
Ron
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RichD
super member
Reged: 11/08/07
Posts: 131
Loc: Derbyshire, UK
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Its a beautiful cluster in 16x70 binoculars, perfectly framed.
I tend to just stand and stare at it though rather than count - we're all different.
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Clear skies
Rich
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RichD
super member
Reged: 11/08/07
Posts: 131
Loc: Derbyshire, UK
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Forgot to say - thanks edz for the post
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Clear skies
Rich
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 11725
Loc: Cumberland, R I , USA42N71.4W
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always welcome
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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jrw11
sage
Reged: 06/09/07
Posts: 458
Loc: U.S.A.
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Ive also liked the view in my 20x80's 
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Celestron C6n -HD Reflector
dual axis drive motors added
Orion 80mm Short tube refractor
Skyscout
Early 70's Pentax 7x50
Garrett Optical 12x60
Garrett Optical 15x70
Oberwerk 20x80 Standards
Canon Rebel Ti (film)
4 Minolta Srt cameras
Mamiya RB67 Pro-s with 180 lens
127mm KL lens for RB
120 and 220 film backs
over 50 other film cameras
several eyepieces
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Reverie
member
Reged: 03/27/08
Posts: 28
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Very interesting topic! 
I could count only 20 stars with 10x50.
Air pollution, light pollution, poor weather...
I hardly get a decent result in my location.
I counted more than 20 with 15x70 5 years ago. Unfortunately I lost most of my observation log.
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Where are the stars now? Where would I have to go in order to see them?
I walk forth into this fractured world, yet my thoughts were forever of the sky.
~Reverie Planetarian~
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Randy Cordell
super member
Reged: 09/16/07
Posts: 196
Loc: Cedar Rapids IA
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Hi Ed,
I got to spend a long time under a pretty decent sky last night. I had my 15x70's trained on M44 for a long time. Our club had their public night last night so there were a lot of people coming and going. I noticed something I have NEVER experienced before and wonder if this is a usual thing or is it atmospheric dependent? While viewing the cluster the very "center" small triangle asterism of three stars appeared to be deeper than the rest. Actually there were two or three sets of stars that appeared this way while looking at the center. However, any stars I looked at directly would appear to move back and become sharper and cause the same three dimensional feel. Have you ever seen anything like this? It was quite unusual. I have a new pair of glasses (a whole different subject!) but wonder if I just was not seeing what everyone else does prior to this? This was using my 15x70's.
As for counting how many stars I could see....I uh...ah-hem...have a printed copy of your chart with me every time I'm out...but in the excitement never seem to get to that count. 
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Randy Cordell
Meade StarFinder 10" F/4.7 Dob, Telrad, Craford, Fans
Bogen 3040 and 3050 Tripods with Orion Paragon-Plus Parallelogram or 3047 head
Oberwerk Mariner 7x50
Pentax PCF WP 8x40
Garrett Optical Gemini 15x70 WP-IF
Laptop running Kubuntu and Stellarium 0.9.1
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mttafire
Pooh-Bah
Reged: 02/02/06
Posts: 1114
Loc: midwest
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I was just looking at M44 night before last w/ my 15x70's.
Good seeing but i didnt count..just looked this night out.
Tonight, Im wanting to go out around 11:30 for another look and also try to find the Sombrero Galaxy.
I sometimes CAN and sometimes CANT see it. Even when viewing seems to be the same. Hopefully tonight will be a successful go at it.
Should be clear and dark!
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God Bless America
Binocular astronomy
for me ONLY.
8x45 Garretts
15x70 Skymasters
2 eyes!
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 11725
Loc: Cumberland, R I , USA42N71.4W
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Quote:
wonder if this is a usual thing or is it atmospheric dependent
sorry to say, I don't recall experiencing this. I would say it is not usual. I would also say it is not atmospheric dependant. I would say it is an illusion, perhaps for you a very neat illusion.
BTW, I had my new Nikon Prostar 7x50 out a few days ago. I counted 45 stars on the M44 chart. LM at the time was about mag 5.2. very early next morning, while observing Cr399, I could clearly see several stars of mag 9.1 and I suspected seeing one star at mag 9.3.
On the same evening I had out my Oberwerk 25x100 and I counted 129 stars in M44.
Also saw NGC 3628 along with M65 & M66 thru the 25x100. Only one member of the M65-M66 pair was seen in the 7x50.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Randy Cordell
super member
Reged: 09/16/07
Posts: 196
Loc: Cedar Rapids IA
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It was very strange and I've never seen that before. I didn't think to try without my glasses. But what I noticed earlier in the evening was that without them my astigmatism is apparent. I never noticed this before either. I am learning new things as my observation skills get more refined, I guess.
How do I determine the limiting magnitude where I am observing? I think there are certain star groups that depending on which stars are detected by naked eye, the LM is determined?
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Randy Cordell
Meade StarFinder 10" F/4.7 Dob, Telrad, Craford, Fans
Bogen 3040 and 3050 Tripods with Orion Paragon-Plus Parallelogram or 3047 head
Oberwerk Mariner 7x50
Pentax PCF WP 8x40
Garrett Optical Gemini 15x70 WP-IF
Laptop running Kubuntu and Stellarium 0.9.1
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 11725
Loc: Cumberland, R I , USA42N71.4W
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see the Best of thread on NELM and use some o the labeled charts in the links.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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RussL
professor emeritus
Reged: 03/18/08
Posts: 744
Loc: Cayce, SC
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Well, thought I'd give a try at counting tonight with my Ultima DX 10x50s. My sky is pretty light polluted, so I didn't expect to see many stars, but I did the best I could, also using averted vision. The biggest problem I had was trying to count while hand-holding the binos. So, I took a long time staring with my head leaning back against my truck cab. That helped some, but things were still fairly shaky. Without overestimating, I'd say I could make out about 20, maybe 25 stars of various magnitudes. That's also guessing at the field indicated on the chart in the link as I didn't have a printed copy with me. The sky was clear and the air was fairly steady, although there was some haze to the east. How far the edges of that haze reached I couldn't tell for sure. I'll try again another night to see if I can see more. 
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"Akita mani yo." Observe everything as you walk. (--Lakota)
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BobinKy
scholastic sledgehammer
Reged: 04/27/07
Posts: 754
Loc: Country road
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EdZ--
This is an excellent observing thread. Thank you for leading us through the process and sharing your experience.
. . .
I do a similar exercise using the SkyHound 2 observation planning software. First, at the computer, I select an area to view, draw FOV circle(s) centered upon the brightest star for each of the various binoculars I will be using, and set the star magnitude for each chart.
When I print out the custom star charts (one for each binocular per target area), I have on paper the stars/DSOs that should be visible within my eye cups.
In the field, I mark those stars/DSOs on each instrument's custom chart.
An added caveat, sometimes I go back inside and click on the marked stars to identify their designation. Knowing a star's designation or name is often just a catalog number, however, I have a label for each star/DSO that appears in my eyecups. Similar to carrying a bird or wildflower field guide on a hike in the woods in order to identify what you stop and observe.
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Bob
Kentucky, USA
Binocular Observer
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RussL
professor emeritus
Reged: 03/18/08
Posts: 744
Loc: Cayce, SC
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The sky tonight was not quite as clear in some areas, but I gave it another go in my 10x50s, counting 15 or so of the brightest stars. This may sound strange, but during three tries at counting I began to notice a configuration that oddly reminded me of the shape of the Hyades. Once I saw it I could in no way avoid interpreting it as such as I tried to count again. I was facing southwest basically so as to be "in front" of the cluster. This was at 9:45pm. I tried to orient myself on the chart, but due to the large number of stars on the chart I was unable to discern the shape I was seeing. Nor am I able to tell if the chart is oriented as if facing southwest. Of course , I have never scrutinized the Beehive this much and so I am quite unfamiliar with it's geometry to such a degree. I tried lying on the ground, but it was no better than leaning on my truck or back in a chair. Perhaps the Hyades-like configuration I saw was an effect of my limited sky conditions, or perhaps merely something my brain translated as such. Nonetheless, it proved to be a tool by which I counted stars time after time. An abbreviated chart might help me tell just which stars I am seeing. Interesting.
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"Akita mani yo." Observe everything as you walk. (--Lakota)
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 11725
Loc: Cumberland, R I , USA42N71.4W
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Quote:
Perhaps the Hyades-like configuration I saw was an effect of my limited sky conditions, or perhaps merely something my brain translated as such. Nonetheless, it proved to be a tool by which I counted stars time after time.
I know the configuration about which you speak. It's about 2" below the center on my chart. It points to the right on the chart. It could be described as the Hyades. I call it Cepheus.
There is also a Cassiopeia figure on the M44 chart, but it is only seen in it entirity when using 100 binocular telescope.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 4923
Loc: San Francisco Bay Area, Calif...
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Hi Ed,
Very intereting list of star counts and the binoculars used.
Sorry if I missed it, but are you doing these counts with all the binoculars mounted or hand held?
Thanks,
Rich
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 11725
Loc: Cumberland, R I , USA42N71.4W
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mounted. handheld the counts go down considerably. Mounted this is essentially a test of limiting magnitude, although i don't have this chart labeled as to magnitudes, obviously more stars is fainter. Refer to the original link in this thread for all other observations using this M44 chart, Cr399 (50-60 mags labeled), and M45 (250 mags labeled to mag13.0).
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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RussL
professor emeritus
Reged: 03/18/08
Posts: 744
Loc: Cayce, SC
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Quote:
I know the configuration about which you speak. It's about 2" below the center on my chart. It points to the right on the chart. It could be described as the Hyades. I call it Cepheus.
Hi Ed,
Ah, yes, I see that. After my post last night I found a photo in my Audubon book that clearly showed that shape, although I noticed that it was quite a close in view of the cluster, the entire area of the photo being only about one-fourth the size of your chart. Now that I see the Hyades/Cepheus shape on the chart, it gives me some idea as to the field in which I was trying to count stars. Perhaps I can count more than I thought. I now have a printed copy of the chart and will try again, chart in hand, to see what results I get.
I can also see why you could call the shape Cepheus.
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"Akita mani yo." Observe everything as you walk. (--Lakota)
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 4923
Loc: San Francisco Bay Area, Calif...
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Thanks, Ed!
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alessandro71
member
Reged: 09/04/07
Posts: 95
Loc: Rho (Milan - Italy)
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site 45°31'N - 9°02'E
date and local time 8 may - 22:00
bad seeing (night sky badly polluted, light and haze)
11x56 (oberw.) mounted
M44, between Asellus Australis-Boraelis easy spotted / counted 17 stars.
Around that, I barely saw 9 other stars
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alessandro
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Randy Cordell
super member
Reged: 09/16/07
Posts: 196
Loc: Cedar Rapids IA
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Hi Ed,
I finally got a sky I could work with in conjunction with a non-work night. Whoo-HOO! So, based on your chart for Ursa Minor, I have a Mag 4.3 sky here tonight with a waxing crescent moon of 34% sitting just outside of Cancer. Moderate light pollution and observing from my driveway. I was surprised that the sky would actually be considered mag 4.! I would have expected 3 something. 4 is not good! So thanks for that tool as well.
Okay. So with my mounted GO 15x70's I saw 30 stars within the circle boundary on your chart. I changed to my 7x50's mounted and I saw 25.
The Cephus asterism is obvious. I forgot you mentioned a Cassiopeia and so didn't look for that one. Up this thread where I made reference to a small triangular grouping that I said was in the "center"....that is the three at the peak of Cephus "roof" and not in the center at all.
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Randy Cordell
Meade StarFinder 10" F/4.7 Dob, Telrad, Craford, Fans
Bogen 3040 and 3050 Tripods with Orion Paragon-Plus Parallelogram or 3047 head
Oberwerk Mariner 7x50
Pentax PCF WP 8x40
Garrett Optical Gemini 15x70 WP-IF
Laptop running Kubuntu and Stellarium 0.9.1
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 11725
Loc: Cumberland, R I , USA42N71.4W
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Sky magnitude can vary considerably from one direction in the sky to another. I would expect the area of sky near a moon to be considerably brighter than the area near the Little Dipper.
I actually have a few stars labled on almost every one of my star chart pages, so I can get an idea of the sky in the vicinity of my observation.
When sky is fairly dark mag5, I'm seeing about 40-45 stars in 7x50s. Alsmost twice as many with a 15x70.
There is a small triangle with two bright stars, almost dead center.
Cassiopeia is upside down in the upper left quadrant. it can't bee seen in low powered binoculars. In fact to see the entire asterism needs mag 5.4 skies and 25x100 or better.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Randy Cordell
super member
Reged: 09/16/07
Posts: 196
Loc: Cedar Rapids IA
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Edz,
What do you do with the stars that straddle the border of your chart?
Last night I counted 43 in my 15x70's and 34 in both my Pentax 8x40 and OB Mariner 7x50. Skies were 5.6 based on the Polaris LM chart. This is much lower than your count (on the same instrument in one case) under lessor skies. There are stars that I think I see pop in but then I can never quite see them again, even averted, so it's hard to count. But it's fun trying. I'm getting the hang of the borders of your chart.
Also, what is the source of boundaries of clusters like this?
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Randy Cordell
Meade StarFinder 10" F/4.7 Dob, Telrad, Craford, Fans
Bogen 3040 and 3050 Tripods with Orion Paragon-Plus Parallelogram or 3047 head
Oberwerk Mariner 7x50
Pentax PCF WP 8x40
Garrett Optical Gemini 15x70 WP-IF
Laptop running Kubuntu and Stellarium 0.9.1
Edited by Randy Cordell (05/22/08 12:16 PM)
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 11725
Loc: Cumberland, R I , USA42N71.4W
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Just a bit on your NELM. Just the other night was full moon. I was observing towards the noth and I checked stars in Ursa Minor and could see all the way to mag 5.0. however, behind me in the vicinity of the full moon. best I could see was about mag 4.0.
The NELM reading you want to take should be taken in the vicinity of the object you are viewing. Sky can vary considerably from one region to another.
Straddle stars. If they are inside or on the line, I consider them IN.
BTW, seeing the faintest stars takes considerable effort. In some of the LM studies/counts that I've done, I can count the first 40-50 stars in the first few minutes. I might take 10 minutes to see the last 4-5 stars.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Randy Cordell
super member
Reged: 09/16/07
Posts: 196
Loc: Cedar Rapids IA
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Oh yeah. Good point. Ursa Minor was in nice dark sky much higher than M44. It is hanging low now and for me it's in the glow of a nearby town, not a lot but definately not as dark as Umi.
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Randy Cordell
Meade StarFinder 10" F/4.7 Dob, Telrad, Craford, Fans
Bogen 3040 and 3050 Tripods with Orion Paragon-Plus Parallelogram or 3047 head
Oberwerk Mariner 7x50
Pentax PCF WP 8x40
Garrett Optical Gemini 15x70 WP-IF
Laptop running Kubuntu and Stellarium 0.9.1
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