Thursday, October 06, 2005

20050930 Weekend - Observations & Remarks

Location: TotL, NYC

Dates of Observations
-- 30 Sept 2005 / 8:25pm ~ 12:30am; Party - Charlie & Kin
-- 01 Oct 2005 8:15pm ~ 1:55am; Party - Charlie, Kin, and Ben

Eqpt: Naked Eyes; Fujinon 7x50 bins (handheld); Tripod-mounted Takahashi bins; Teleport 10" reflector


- Object List -

Objects (Asterisk indicates attempted, not seen)
09/30 session - NGC225, NGC7789, STT 131 (lambda Cas) NGC1039 (M34), NGC1023, NGC1245*, NGC2403*

10/01 session - NGC225, NGC581 (M103), STF 131, NGC663, TR1, NGC253, HJ 3407, NGC6853 (M27), NGC6838 (M71)

Objects seen exclusively in others scopes M56, Charlie's SAR

Objects shown to public NGC224 (M31/32), NGC869/884

- Remarks -

When starhopping for an object it is not unusual to see doubles along the way. I don't make a habit of recording them because sometimes I don't know exactly where I am and the planetarium programs I have don't have good double star catalogs. (I could create one or import one for Planetarium for the Palm but haven't yet.) However, over the weekend, I did recognize a couple of doubles that I really hadn't noticed in the past.

NGC581, more commonly known as M103, has a conspicuous double, WDS STF 131, as the brightest star on the NNW end. This was evident in TP-10, but not in the Tak bins. As most of us adopt our own way to interface with the sky, personal asterisms come play to an important role. I have many throughout the sky and they take on a variety of personalities or familiar shapes. M103 strikes me as a pair of slippers. The first slipper consists of three bright stars in a line, STF 131 on the NNW end and the line extends to the toe star nearly 6’ to the SSE. A dimmer 4th star lies west of the second & toe star. This is apparent with small optics; larger optics brings out the second slipper crosswise. How do you see it?

While near M103, I had Tr1 in mind. I have never seen this before and have tried in the Tak bins and refractor but have never definitively id’ed it. Near M103 there is a small tight cluster of three or four stars that one could think is the cluster. This fooler is not in the right location when looking at the chart. Having the 10” I looked for this cluster in the same fov with M103. I was surprised to find it very easily. Its appearance different from expectation. Nonetheless, it was detected under low and observed at medium magnifications. After identifying the cluster, it is now apparent in the Tak bins, albeit small, hazy patch. In the Nagler 17mm EP, four bright stars are easily apparent in a 4.5’ NE – SW line. There are two doubles which I haven’t id’ed yet. There are dimmer stars sprinkled about, bringing the count to 10 stars. Really no concentration, but richer towards the end that has the double.

Robert Julius Trumpler was an impressive astronomer. His efforts and contributions to science are fascinating. He used the Lick Observatory and published in their journal an article, “Preliminary results on the distances, dimensions and space distribution of open star clusters.” This was period of time where visual astronomy was being waning to astro-photography and astrophysical science discipline. His work with creating a list of more than 100 open clusters for his study relied on the Franklin-Adams photographic plates. He devised a classification system for open clusters. One will see this 3-character code that identifies specific features of an open cluster. His study of open clusters was toward the effort of determining the structure of the Milky Way. He is responsible for the discovery of the first evidence of the presence of an interstellar medium. There is an interesting debate he had with Edwin Hubble. Often I"ll drop in on TR2 often as it is nearby Stock2 and the Double Cluster. Tr2 is more interesting, as it is larger and has a prominent red star central to the cluster. See for yourself, it is well situated now in Perseus and is an easy binocular object.

One last object that I’ll comment about in Cassiopeia is NGC7789, Caroline’s Cluster. This is a tough object for binoculars. I have thought that I have seen this before in scope and Charlie’s bins. But after observing this OC, I reconsider. This is an awfully faint object, exhibiting low surface brightness and not much contrast to the background sky. I needed the 10” to definitively detect and resolve this cluster. I think Charlie described it as a bow tie shape, which it did resemble, its steallar concentration more on the W edge. With the Nagler 17mm EP, I was able to count 28 stars. Like a lot of them, I really don’t know how to determine the edges of the cluster unless it is strikingly obvious. Even after locating the OC, I returned to it unable to see it with the Tak bins.

I had starhopped to the field where NGC253, Sculptor Galaxy, resides. I wasn't able to detect this bright galaxy on two different occasions on Saturday night. I was surprised because my observation from Custer Institute site left me the impression that this galaxy is definitely do-able from TotL. Unfortunately, neither the Tak nor the TP-10 could help in spotting it. At one point, I thought I may have sensed a very, very faint glow. I asked Charlie to look in the Nagler 17mm EP fov and if he could detect any object with a very, very low contrast. Instead he described seeing a double. This turned out to be WDS HJ 3407.


references excerpted from Cartes du Ciel, ver. 2.76
Double Star
STF 131 AB
Magnitude: 7.30/ 9.90
1827: 13.8"/143°
1999: 13.8"/143°
Spectral Class: B5Iab
Note: Np
DM:+59 271
J2000 RA: 1h33m14.00s DE:+60°41'11.0"


Double StarHJ 3407
Magnitude: 8.80/ 8.94
1835: 15.0"/126°
1991: 12.9"/127°
Spectral Class: A9/F0V
Note: Np
DM:-25 343
J2000 RA: 0h54m00.00s DE:-25°03'00.0"