Ivan Maly
June 7th, 2013, 09:17 PM
Notes from a brief survey of Ursa Minor I did on Monday with my 16”. It was fine summer night, and the UMi area measured 21.58 mpsas on my SQM-L. Speaking of bears, the specimen that was skirting the field at dusk was anything but little. I (however) limited my targets to Polarissima Borealis, a John Herschel asterism, a couple of KPGs (Karachentsev Isolated Pairs of Galaxies), the bright spiral NGC 6217, the core of Abell 2256, and Shakhbazian 166.
695
Polarissima Borealis, NGC 3172. John Herschel. At 225x with 8 mm Ethos, slightly elongated 1x2-2x3 NE-SW, smoothly concentrated. Glimpses of starlike nucleus. Star NW about 1.5-2 sizes. 00:10.
NGC 5385 near 4 UMi is another J. Herschel discovery. It is not considered a true cluster. At 45x with Pentax 40 XW it is unmistakable and nicely framed with 2 Uranometria stars. It is just SW of the pair and has the shape of a hang glider flying SW. It is fully resolved at this magnification and consists of uniform stars. It is sharply outlined in a field mostly devoid of stars. It is not in Uranometria (marked in mine). 00:25.
NGC 5909 and 5912, discovered by W. Herschel, are a true pair in the KPG catalog. Near Kocab. They are noticeable already at 45x. At 225x, they are almost touching. NGC 5909 is elongated 2x1, with diffuse edges and practically no central concentration. NGC 5912 is smoothly concentrated, and appears much brighter and a little smaller. MCG+13-11-12 to the S certainly does not look smaller, but its boundaries are indistinct. 00:45.
NGC 6068-A is another KPG pair near the bowl of the Small Dipper. 6068 was discovered by W. Herschel. 6068 is elongated 3x2, with a little concentration, diffuse edges, and a starlike nucleus. Its orientation is NNW-SSE. Separated by about the major axis length to the WSW is a small short spindle of 6068A. Its elongation is more NS and stronger, 1x2. There is no concentration and edges look sharper. There is a triangle of stars just fitting between the galaxies and a star just W of 6068A. 01:15
NGC 6217 is the only Herschel 400 object in UMi. (I observed it with my 4” f/5.5 Televue in July 2010.) It is quite prominent at 45x. At 225x, its barred nature is immediately visible, along with a segmented ring. 300x with Abbe II 6 mm makes the structure clearer. (Sketch) 02:00.
696 NGC 6217 (ballpen sketch)
NGC 6331 is the W. Herschel discovery in the center of Abell 2256 in UMi, ~750 Mly. On DSS it seems to be a pair of compact galaxies. It is the most conspicuous member visually. 3 more galaxies are visible to its E in a chain. I also noticed 2 more within the bright asterism to the SE. See marked chart. 02:40.
702 Abell 2256 core (marked Faint Fuzzies chart)
[Abell 2256 is 746 Mly away according to NED. In 1977, Faber and Dressler created a handy catalog of 14 bright members of this cluster (http://adsabs.harvard.edu/abs/1977AJ.....82..187F). In the light of this paper, my observations are not unexpected: what I saw were the Faber-Dressler members within this central area of the cluster, as indicated in red on the chart using the Faber-Dressler letters. NGC 6331 itself probably includes three components, the two brightest being plotted on the Faint Fuzzies chart and cataloged by Faber and Dressler as A and B. They remained unresolved within the large elongated haze as outlined in the field by hand on my chart. The scribbled label next to this oval is “6331”. Arrowheads mark the other galaxies and stars that were seen.]
Just N near Epsilon UMi, the first star in the handle from the bowl, the compact group Shakhbazian 166 at the edge of Abell 2247 is a nice chain of 5 galaxies at 225x, as marked on chart. 03:10.
700 Shk 166 (marked and re-labeled Faint Fuzzies chart)
[Shk 166 is 498 Mly away by redshift according to NED. On the chart that is scanned here, the visible galaxies and stars that were marked with arrowheads in the field. I also re-labeled the galaxies with new identifications; more about this in my posts in the OOTW Shk 166 thread.]
695
Polarissima Borealis, NGC 3172. John Herschel. At 225x with 8 mm Ethos, slightly elongated 1x2-2x3 NE-SW, smoothly concentrated. Glimpses of starlike nucleus. Star NW about 1.5-2 sizes. 00:10.
NGC 5385 near 4 UMi is another J. Herschel discovery. It is not considered a true cluster. At 45x with Pentax 40 XW it is unmistakable and nicely framed with 2 Uranometria stars. It is just SW of the pair and has the shape of a hang glider flying SW. It is fully resolved at this magnification and consists of uniform stars. It is sharply outlined in a field mostly devoid of stars. It is not in Uranometria (marked in mine). 00:25.
NGC 5909 and 5912, discovered by W. Herschel, are a true pair in the KPG catalog. Near Kocab. They are noticeable already at 45x. At 225x, they are almost touching. NGC 5909 is elongated 2x1, with diffuse edges and practically no central concentration. NGC 5912 is smoothly concentrated, and appears much brighter and a little smaller. MCG+13-11-12 to the S certainly does not look smaller, but its boundaries are indistinct. 00:45.
NGC 6068-A is another KPG pair near the bowl of the Small Dipper. 6068 was discovered by W. Herschel. 6068 is elongated 3x2, with a little concentration, diffuse edges, and a starlike nucleus. Its orientation is NNW-SSE. Separated by about the major axis length to the WSW is a small short spindle of 6068A. Its elongation is more NS and stronger, 1x2. There is no concentration and edges look sharper. There is a triangle of stars just fitting between the galaxies and a star just W of 6068A. 01:15
NGC 6217 is the only Herschel 400 object in UMi. (I observed it with my 4” f/5.5 Televue in July 2010.) It is quite prominent at 45x. At 225x, its barred nature is immediately visible, along with a segmented ring. 300x with Abbe II 6 mm makes the structure clearer. (Sketch) 02:00.
696 NGC 6217 (ballpen sketch)
NGC 6331 is the W. Herschel discovery in the center of Abell 2256 in UMi, ~750 Mly. On DSS it seems to be a pair of compact galaxies. It is the most conspicuous member visually. 3 more galaxies are visible to its E in a chain. I also noticed 2 more within the bright asterism to the SE. See marked chart. 02:40.
702 Abell 2256 core (marked Faint Fuzzies chart)
[Abell 2256 is 746 Mly away according to NED. In 1977, Faber and Dressler created a handy catalog of 14 bright members of this cluster (http://adsabs.harvard.edu/abs/1977AJ.....82..187F). In the light of this paper, my observations are not unexpected: what I saw were the Faber-Dressler members within this central area of the cluster, as indicated in red on the chart using the Faber-Dressler letters. NGC 6331 itself probably includes three components, the two brightest being plotted on the Faint Fuzzies chart and cataloged by Faber and Dressler as A and B. They remained unresolved within the large elongated haze as outlined in the field by hand on my chart. The scribbled label next to this oval is “6331”. Arrowheads mark the other galaxies and stars that were seen.]
Just N near Epsilon UMi, the first star in the handle from the bowl, the compact group Shakhbazian 166 at the edge of Abell 2247 is a nice chain of 5 galaxies at 225x, as marked on chart. 03:10.
700 Shk 166 (marked and re-labeled Faint Fuzzies chart)
[Shk 166 is 498 Mly away by redshift according to NED. On the chart that is scanned here, the visible galaxies and stars that were marked with arrowheads in the field. I also re-labeled the galaxies with new identifications; more about this in my posts in the OOTW Shk 166 thread.]