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8/23/2009

Herschel 400 August 16 and 17th 2009

Well I got out the night of August 16 and 17th and had a relatively good session. Seeing was pretty constant at around 6/10 that night and I was observing from my backyard.

I used O'Meara's guide and (I have another observation to put up for the 22nd of August) I find that his main maps are relatively useless as I use my Sky Atlas 2000 to a better affect. Having said that I have to say that often his detail maps do help in locating objects. I really, REALLY wish the publisher had put the book into a spiral bound version for the field as I am worried about the back making it over this adventure.

My other recommendation on the book, is probably based on the moon cycle. Right now near the first of the month the moon is full so I really recommend in that circumstance that you hunt down the next month's DSO's in the new moon cycle. So for example, I am finding that in August, Sagittarius is a focus constellation. For me at 41 degrees north Sagittarius in mid to late August is only up from 10:00p.m. until around 12:30a.m. After that it is too low for me to observe because of these mountains to the SW. It would have been better for me to observe August items in mid to late July and then September over the last two weeks. This just means I will have to get the objects I miss next year. That's fine since I am giving myself two years to complete the list.

All observations were made using an XT10. Limited Magnitude (LM) from O'Meara's H 400 Guide. Check my UT time as I am adding 5 hours to my local time (Mountain Standard) and placing it in military time.

NGC 6440 Globular Cluster in Ophiuchus
August 16, 2009
21mm Stratus at 57x
Sketched at 13mm Stratus at 92x
Seeing 6/10
03:39p.m. UT
LM 9.2


My first object that night was NGC 6440. I had recently observed NGC 6445 so getting here was easy. I simply started at Kaus Borealis and using M8, M11 and M23 as my hopping points and followed the four curving stars down from M23 to NGC 6445 and then went south down to NGC 6440 which sits in a chain of 4 stars, separating the bottom two from the top two. Averted vision really helps here bringing out a star like inner core with a halo around it. At 200x the halo increased while taking away the core.




























From the Digital Sky Survey:




























I included NGC 6445 in the sketch. I will post the actual sketch here after I get them scanned.

NGC 6638 Globular Cluster in Sagittarius
August 16, 2009
XT10
13mm Stratus @ 92x
5mm Hyperion @ 200x
Seeing 6/10
04:15 UT
LM 9.0

Easy target to find. I used the Telrad to Kaus Borealis and went to Lamoda Sagittari. I went east and down and you can't miss it. It is a faint fuzzy object and I could not resolve any stars at 200x as conditions wouldn't allow more than that. I did detect hints of a faint core and a stronger light to the west of this object.




























From the Digital Sky Survey:
























NGC 6642 Globular Cluster in Sagittarius
August 16, 2009
XT10
13mm Stratus @ 92x
5mm Hyperion @ 200x
Seeing 6/10
04:55 UT
LM 9.1

O'Meara's guide worked just fine on this object, and easy to find. I've been here and viewed this before but never recorded the observation. At 92x there was a hint of a strong star like core surrounding by a halo with the halo making up 80% of the view. At 200x the core really shines with averted vision and when seeing permits and clears. Nothing fanciful here as no stars are resolved, no tendrils seen, just a sharp halo ball of fuzz! I sketched it at 92x to include the field though I did consider 200x because I saw more detail on the object. Seeing seemed to improve.





























From the Digital Sky Survey




























Error in the sketch. Another switch of numbers!!! Argggggghhhh. I'll have to watch that.

NGC 6517 Globular Cluster in Ophiuchus
August 17, 2009
05:37 UT
XT10
13mm Stratus @ 92x
LM 10.1

I wanted to try for NGC 6629 a planetary by NGC 6642 but it was too low and I would have had to remove my light shield and at that point would have lost all details. So I moved onward. Followed O'Meara's instructions here again and they worked well with the Sky Atlas 2000. Went to Tau Ophiuchus using my Telrad and by the star is a triangle asterism of a triangle point at Tau, well, really just off of it. I went to the tip of the triangle which is also part of three stars from the right bottom I angled downward and to the right and I saw 2 faint stars and then a brighter one. The globular lies right above the bright star and to the right of the second faint star.

I could discern a bright core with direct vison and a halo around it. The core seemed to come and go during the observation though. Averted vision just off the object brings the core back. I found being dark adapted really helped here. No stars could be resolved.




























From the Digital Sky Survey
























NGC 6781 Planetary Nebula in Aguila
August 17, 2009
05:55 UT
Seeing 7/10
LM 11.4
13mm Stratus @ 92x
5mm Hyperion @ 200x
Orion Ultrablock NB Filter

Well, the southern constellations were fading into the west like on of Tolkien's Elves so I moved on in O'Meara's book. I decided to go for the planetary before the open clusters because of my fondness of planetary nebula.

NGC 6781 is a rather LARGE planetary, one of the largest I've seen. I went to Delta Aguilae, the top of the tail of the eagle, and followed O'Meara's directions. From Delta Aq. I moved over to 222 Aquilae. Between 22 and 19 Aguilae are three stars that are north to south. Follow those three stars up to the third one on the top and the PN is up and to the left in my reflectors EP. I spotted it first without a filter as dark adaptation helped.

The PN seems to have an irregular shape; it appears to be a ball but then I get moments where I see it more egg shape. The edge is diffused and only a grayish or grayish white color is present. Using my Orion Ultrablock Filter brought out the details I listed above (irregular size and the slight brightness on one side) and makes this PN really stick out. A nice object to view in the summer time. No central star is visible.































From the Digital Sky Survey:





















NGC 6755 Open Cluster in Aquila
August 17, 2009
07:20 UT
Seeing 7/10
LM 7.5
XT10
13mm Stratus @ 92x
21mm Stratus @ 57x

I followed O'Meara's directions on this until I got to Delta Aquilae. That is where it got hard using his directions for me, and in this case his finder chart did not help me. I finally got to the cluster after thirty minutes of searching and re-reading my Sky Atlas 2000. Very scattered cluster that has a wedge shape to it. I felt at times I could detect a glow around it, though I haven't confirmed that yet. The chains of stars are nice. I did not sketch this item though I did make a note to come back and sketch it. I have to be at work/school tomorrow for a meeting at 11:00a.m. so I couldn't stay out that much longer.

From Digital Sky Survey:




























NGC 6756 Open Cluster in Aquila
07:40 UT
Seeing 7/10
LM 10.6
XT10
13mm Stratus @ 92x

This and NGC 6755 are relatively close together and could be a close double cluster I guess. Not much to this one, its small, compact and elongated. I counted about 12 to 13 members present. No sketch of this one.

From the Digital Sky Survey:




























That was it, as it was that night, so it is now, I'm tired, and need to go to bed. I'll post Friday's session tomorrow, then I would like to add the scans of these two sessions and their audio this week if I have time . . . . key word, if I have time. I will add the audio by next weekend though since I have had several requests for it. I may get it sooner since the skies are bad the next two days. Clear skies to you.

Jay

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