Tuesday, August 19, 2014

Groups in Her and Dra

August 18, 2014. Beaver Meadow. 16”. Beginning Alvin Huey’s selected small galaxy groups. Clear, transparency average. Seeing average with good around. 10-15 C. Humidity 80%. SQM-L 21.16 overhead in Her. Astronomical twilight 22:00, moonrise 01:15.


Marth's chain in Hercules. All labeled galaxies are at ~450 Mly.

The group in Her, page 126. At the low power with the Pentax XW40, NGC 6269 is visible, and more nebulous spots in the area are suspected.
At the high power with the 8 mm Ethos, NGC 6269 [WBL 625-03] is immediately obvious and quite large. Its EW elongation is hardly noticeable. The galaxy is smoothly concentrated to the middle. SE of it is a line of 4 stars, whose brightness diminishes E to W. S of the galaxy is a faint star. A similar star is to the NE.
To the W is a brighter star, and past is another prominent galaxy, which is only slightly smaller than NGC 6269. This galaxy is NGC 6265 [WBL 625-02].
Farther W along the same line is the even fainter NGC 6264 [WBL 625-01]. A slight NS elongation is noticeable in this galaxy. SW of it is a field star.
Farther W is a bright star, and S of it NGC 6263. It appears slightly elongated toward the field S to its S.
NGC 6261 to the N is a lens oriented EW.
All five galaxies fit in the field of the Ethos. This group is AWM 5. The first 4 galaxies form a chain, and the last one is located to the N of the W end of this chain. The chain is oriented EW. [The chain was discovered by Marth and the NW outlier by Stephan.]


Swift's group in Draco. -1-3, >500 Mly; -4, 350 Mly; -5, 60 Mly.

Time 23:40. 3rd group in Dra, page 133. [NGC identifications in this field differ. 6 galaxies in it were discovered by Swift.] “NGC 6463” [WBL 645-03] is the first galaxy noticeable in this group. It forms a right triangle with 2 field stars to its S and E.
The next most prominent galaxy is in the core of the group that lies E of “NGC 6463” [WBL 645-03]. This galaxy is “NGC 6472” [WBL 645-05]. It lies immediately SW of a faint field star. It is elongated N to S and has comparatively well-defined edges. According to the DSS, what is seen is the elongated core, or possibly bar, of this galaxy. The much larger halo outlined by a spiral arm is not seen.
“NGC 6477” [PGC 2703230] is a small nebulous spot to the W.
“NGC 6470” [WBL 645-04] is the highly elongated galaxy S of “NGC 6472” [WBL 645-05]. It is only suspected with this ocular. However, its compact companion located immediately to the E between and a field star can be seen intermittently.
At 300x with the 6-mm Zeiss, “NGC 6470” [WBL 645-04] is still not definite despite a few glimpses, although the companion [PGC 60779] is visible.
“NGC 6476” [NGC 6456, WBL 645-02] farther W is also a relatively small diffuse spot.
To the S is a bright field star. Next to it, “CGCG 321-22” [CGCG 321-32, WBL 645-01] can be glimpsed with the 6-mm Zeiss.
Returning to the medium power with the Ethos, I am getting repeated glimpses of the thin, elongated “NGC 6470” [WBL 645-04].
Anonymous galaxy labeled “1” on the DSS is visible with the Ethos, but the star on its W edge is not resolved [PGC 2701716].
The entire group fits in the field of the Ethos. The main part of the group that can be almost held simultaneously is the trapezium formed by the compact companion of “NGC 6470” [PGC 60779] and by “NGC 6472, -77, and -63” [WBL 645-05, PGC 2703230, WBL 645-03]. It occupies the central part of the field. While observing this central group of 4, I am still getting repeated glimpses of the core of “NGC 6470” [WBL 645-04].

Wednesday, August 13, 2014

NGC 5907, Herschels in Lyr and Vul


July 31, 2014. Beaver Meadow. 16”. Clear, transparency average, seeing good to average. Astronomical twilight 22:25, 04:15. Moonset 22:35. 15 C. 70-80% humidity.
NGC 5907 is impressive already at the low power, occupying seemingly 1/7th of the field of the Pentax XW40. It is very thin, probably 10x1, and although the ends taper to sharp tips smoothly, there is very little concentration to the middle and no bulge. At the high power with the 8-mm Ethos, the central concentration is more noticeable. There is a faint star off the SW side of the core. The galaxy is elongated NW to SW. There is an immediate suggestion of an equatorial dust lane in the SE half. In the center the equatorial dust lane appears toward the SW side of the core. The galaxy is occupying most, or at least one-half of the field of the Ethos. 23:20. SQM-L 21.05 overhead and in the area of NGC 5907.
Midnight. Herschel objects in Lyra. There is only one. NGC 6646. Inside a triangle of equally bright stars that occupies most of the field of 8-mm Ethos. The galaxy is concentrated to the middle, with diffuse edges. Elongated 3x2, roughly EW, pointing at the more distant star in the triangle. The IC companions 1288 and 1289 just fit in the field of view.
Herschel objects in Vul. NGC 6793 is an VIII-th class open cluster located from Albireo. Albireo at the low power is a tight but fully resolved pair of the brighter orange star and the fainter white or slightly topaz-colored companion. NGC 6793 is immediately noticeable at the low power. It is located inside an incomplete ring of Uranometria stars that almost outlines the field of the Pentax. The cluster itself consists primarily of stars of uniform brightness. It is completely resolved and transparent at this magnification. It appears significantly larger, perhaps two times larger than its symbol in Uranometria. It seems to involve a triangle of Uranometria stars that on the chart is outside the symbol, although these stars are somewhat brighter than the rest in the cluster. The stars of the cluster form a pattern that resembles an asymmetrical Sc-type galaxy with a core, bar, and one arm, which is curving S and W, then N along the bar.
S of it is the Coathanger, Collinder 399, that is larger than the field of the Pentax. Farther S is Palomar 10. The observation is uncertain, at the high power. It seems to be located SW of a field star.
NGC 6800 is another Herschel class VIII cluster. It is actually on the way to the previous Herschel object from Albireo. Once its location is known, the cluster is immediately obvious at the low power. It is approximately 3 times larger than its symbol in Uranometria, and extended approximately 3x1 EW. It consists of stars of uniform brightness that outline a figure resembling a mushroom with a broad hat oriented EW and a stocky stem pointing S. The interior of the figure is essentially free of stars.
01:20. Arrival of thin clouds as predicted by CSC.
Time 01:40. Cleared again. NGC 6802, class VI, is the cluster at the end of the Coathanger. It is obvious at the low power, unresolved save for perhaps 1 or 2 members in the center. Appears textured, elongated 3x1 NS. At the high power, the ends no longer appear tapered. The E side looks flattened and the W one jagged. The cluster seems to be fully resolved, although many stars are just on the threshold. Brighter stars are on the N end. Overall the stars are relatively uniform.
02:25. NGC 6823 is visible at the low power as a small group of relatively faint stars in the rich field. There are 2 Uranometria stars that dominate the group. At the high power, the cluster is adequately framed by the Ethos, although it is not very well detached from the rich field. In the center is a small group of 4 stars, 2 bright ones and 2 faint ones in between. This group is surrounded by perhaps 2 dozen members scattered in the form of a ring, approximately 1/3 of the field of the Ethos. This cluster is Herschel class VII.


Wednesday, August 6, 2014

Last Summer Messiers


July 24, 2014. Cherry Springs. 16”. Clear, transparency above average to transparent, seeing average to good. 10-15 deg. C, 60-70% humidity. Astronomical twilight 22:35 to 04:00. 21.4 [mpsas] overhead, 21.3 in the area of M20 [by SQM-L at 01:00].

M20
M20 [see sketch] at the low power with the 40-mm Pentax looks like a double nebulosity. Each half concentrated around a bright star. Intersecting narrow dust lanes visible in the S half. The star in the center is white and double. The N half is almost equal in size, similarly round in outline. The star in the center has a warm tinge. At the medium power with the 13-mm Ethos, the reflection component is distinctly non-round. The emission component shows 4 lobes, and the dust lanes have sharp and complex outlines. The central star in the emission component now shows a faint companion of the N bright star. OIII filter darkens the sky background and eliminates the reflection aureole around the emission part. It also darkens the emission part; the nebula visually contracts. Only three lobes stand out, and the outlines of the dark lanes are now smoother; the detail is lost. High-power observation finished 01:00.
M21 at the low power shares the field with M20. It is dominated by the unequally bright double lucida. At the high power it almost fills the field of the 8-mm Ethos and has an appearance of an angular bowtie with the lucida in the middle. The vertical of the bowtie is oriented roughly E to W, and the W ends are more extended than the E ones. The N half is smaller than the S one.
M28 at the low power is small, concentrated, and textured. At the high power it is partially resolved, almost to the center. The distinctive feature is an arm that emanates from the N side close to the core and runs in the sparse halo, curving W. Inwards of the arm is a comparatively dark sector.
M22 at the low power is large and resolved to the center. Elongated NS. More stars are resolved on the W side. At the high power it fills the field of the Ethos. Individual bright stars are seen in front of the center, although there is also bright unresolved background. The bright stars in the core form a triangle, and there is a distinctive checkmark of bright stars off the triangle’s NNE side.
M23 at the low power is nicely framed by the Pentax and completely resolved. The stars are of uniform brightness and density. The main mass of stars is elongated SSW to NNE and has well-defined edges. The distinctive feature is a straight line of faint stars, seemingly emanating from the middle of the W side and running to a bright star, which may be called the lucida of the entire cluster. This star has a yellowish, or more likely topaz, tinge.
M24 at the low power is a marvelous star cloud that is one field of the Pentax wide and two fields long, although all the main features can be fit into a single field. These include, along the N edge, the dust clouds B92, B93, and B307. Opposite, on the S edge, is also a distinct dust cloud. On the inward edge of B93 is a foreground small cluster Collinder 469. NGC 6603, closer to the opposite side, is a round and only slightly concentrated, textured patch. At the high power, NGC 6603 appears fully resolved and transparent, to a remarkably dark background. Its distinctive feature is a line of stars running across the center and neighbored by dark areas. This line runs NW to SE.
M25 at the low power is nicely framed by the Pentax. It is completely resolved. The stars are not very numerous. There are three bright stars, and the rest are of comparatively uniform brightness. The fainter stars run in a highly elongated group from the W bright star to the S one and continue farther SE. There is a curious very small Capricorn-shaped group of faint yellowish stars in the center of the large group, and immediately to the W of the S bright star.
Time 02:10. M26 at the low power is incompletely resolved. It is flanked by 2 close double stars, and seemingly superimposed on it is a group of 4 bright stars that, although wider, reminded me of the Scutum asterism. At the high magnification, this shield-like asterism is somewhat lost. The W-most star in it is the lucida and the other stars are considerably fainter at this magnification, especially the N and the S one. The cluster seems fully resolved. There is a comma-like asterism running off the N star of the shield farther N. The main concentration of the fainter stars is on the S side of the shield. There is a CrB-like asterism to the SW of this group, and an arc formed by several faint stars, separated by a dark gap, to the SE.
M30 is concentrated and textured at the low power. There appears to be a very extended and diffuse halo transitioning rather sharply to the central core. At the high power, the cluster is still only textured in the middle. On the N side of the faint halo there are 3 distinct rays of stars and a longer, but more diffuse and unresolved, arm runs E.
Time 02:30. M57 at the low power is a round, slightly turquoise ring (without a filter). At the high power without a filter, the previously recorded appearance of a ring with smeared-out W and E edges is observed. The color is not pronounced. The central star is invisible with 4-mm Zeiss [450x].
Time 03:20. M56 at the low power is medium-sized. The concentration is smooth. Some stars appear to be resolved on the periphery. At the high power, it is amply framed by the Ethos. The stars are resolved across the center, although there is much unresolved background. Three sparse rays of stars run S. There is a bright star to the W. Absence of sharp concentration is remarkable.
M29 is a small group of stars at the low power. All 8 or so stars are resolved and only marginally well separated from the background of the rich Cygnus milky way. This group can be described as consisting of a Pegasus-like square, or rectangle, facing SW, and a Cassiopeia-like tail of three stars running NE from the NE corner of the rectangle. The 8th star is warmly tinged, and located to the NW of the NW corner of the rectangle. It looks more like a cluster at the high power, chiefly because the field of the Ethos is restricted to the relatively darker area around the described star group. In addition to the 8 bright stars, about twice as many fainter stars are resolved at this magnification and add to the cluster-like appearance.
M27 [see sketch] at the low power shows the apple-core shape with the ends almost meeting on the NW side. Open extensions to the SE are noticeable without a filter. The SW half of the “apple core” is brighter. At the high power, sharp detail is seen at the bases of the extensions. The central star is easily visible without a filter. The SW half of the core is slightly turquoise.


M27

Saturday, July 26, 2014

July New Moon at Club Site

M17

July 22, 2014. Beaver Meadow. 16” [F/4.5]. Clear, transparency average, seeing average to good by CSC. Astronomical twilight 22:47, 03:14. Observations begun 23:15. SQM-L 21.25 overhead and 21.10 in the area of M17.
M17 and M18 at the low power with the 40-mm Pentax are just framed in the field of view. M18 seems to be completely resolved, probably showing just the brightest stars but without a nebulous background. M17 without the filter shows the swan shape. With OIII filter at the same magnification, the IC [4706] nebulosity to the W is noticeable around a pair of faint stars. No such nebulosity is visible around brighter stars or without the filter around that pair of stars. With the filter, there is a loop of mottled nebulosity from the front to the back of the Swan. Low-power observations finished 00:00. Medium-power observations with the 13-mm Ethos finished 00:35. High-power observations with the 8-mm Ethos finished 01:00. [See the drawing, a composite in OIII.] The view without the filter is essentially the same, showing the same details, and the nebulosity is brighter, but the contrast with the sky is lower: the sky is much brighter without the filter.
Time 01:20. M18 at the high power looks essentially the same as at the low power [see description above with M17]. It is just framed by the 8-mm Ethos. There are a dozen bright stars, approximately of equal brightness, and these are the stars that are visible at the low power. They are white in color, and there are a dozen stars that are fainter and also approximately of equal brightness. They are intermingled with the brightest stars. In the center, there is an extended irregular pentagon of bright stars that was visible at the low power, and inside it five faint stars in the form of the letter “Y”. In the SSW, at the periphery of the cluster, there is a curious structure demonstrating the juxtaposition of faint and bright stars. In this case, there are two lines, or very shallow arcs: one formed, or at least flanked, by bright stars, and the other, running parallel to it and bending in the same direction, that is formed by the faint stars. In each case, the flanking stars are brighter than the middle star.
Time 02:00. M75 at the low power is small, compact, and slightly textured. It is indicated from the W and S by a dipper-like asterism that is almost one field of the Pentax wide. At the high power it is unresolved and small in the field of the 8-mm Ethos. Interestingly, at this power it appears almost smooth. There is a bright core that is not sharp, and a fainter, gradually fading halo. A field star is to the SSE. There is a suggestion of flattening from the SSE side, but it may be an illusion connected with an arc of three faint stars that are running on that side of the cluster; however, the stars are well separated by about one cluster diameter from the halo. This arc of stars is twice as close to the center of the cluster as the mentioned brighter field star.
Time 02:15. M52 at the low power is well delineated from the rich Milky Way field. It appears to be mostly resolved, although there may be faint unresolved background. The lucida is on the S edge. It is warmly colored; the rest of the cluster is white. The cluster appears to be triangular, with a faint patch of stars detached from the right-angle corner that is facing approximately NW. The broad and diffuse base of the cluster is facing approximately SE. The two other edges of the triangle are quite sharp. The lucida resides in the S or SW corner of the triangle. The stars in the triangle are concentrated toward its right-angle corner. At the high power with the 8-mm Ethos, the cluster seems fully resolved and transparent, although there are many threshold stars next to the bright ones, which are difficult to see.
Time 02:40. M103 at the low power just fits in the field with Delta Cas. It is located to the NE of the bright star. Three brightest stars run from the SE to the NW across the cluster and define its extent at the low power. The middle one of the three stars has an almost equal companion to the SW, in the middle of the cluster. On the SW edge of the cluster is a fainter star that defines the triangular shape with the two brightest ones. The two stars in the middle are warmly colored, and the other stars, forming the outside triangle, are white. The white color is especially well perceived in the two brightest stars. A sprinkling of fainter stars fills the triangle. At the high power, the lucida in the N corner of the outside triangle, which is Struve 131, is resolved. The main component has a slight topaz coloration, and the fainter companion, pointing inwards into the cluster, appears almost greenish. A much fainter star is at the same distance and on the same line farther inwards. At this magnification the cluster appears to be fully resolved and transparent, and to have black background. The stars are uniformly distributed inside, and to an extent outside, the triangle. The brighter of the two warm-colored stars in the middle retains its coloration at this magnification, and in fact the color is a deeper reddish: [it is] brick-colored.

Saturday, July 19, 2014

Globulars in a Teapot


July 17, 2014. Beaver Meadow. 80 mm ED [Astro-Tech F/7]. Globulars inside the Teapot [and M55]. Clear, transparency average with above average around. Comparatively chilly, relatively humid. Astronomical twilight 22:55, moonrise 23:55. Time 23:00.
M69 at the low power with the 40 mm Pentax is small, round, nebulous, and concentrated. It is located S of a star. At the high power, 8 mm setting of the Pentax zoom, 8-24 mm, appearance changes little but the core seems displaced to the N side in the halo.
M70 at the high power is fainter and less concentrated overall, although the very center is quite bright. Like M69 it does not show any resolution or distinctive graininess. A pair of equally bright stars is to the NNE. A slightly fainter star is on the E edge of the halo.
M54, farther E on the same line forming the base of the Teapot, at the high power has a faint halo that sharply transitions to a bright sharp core.
M55 to the E and S of the Teapot at the low power with the 40-mm Pentax presents a marvelous view, just skimming the edge of the treeline. It is grainy and slightly concentrated, comparatively large, diffuse and resembles Palomar 8 in a 16-inch. At the high power there appear to be a multitude of threshold stars across the globular. The concentration is very weak and broad. A comparatively bright star is on the SSE edge of the halo.
Time 23:40. SQM-L 21.21 overhead, 20.85 under the Teapot, and above 21 at 30 deg in all directions.

Thursday, July 17, 2014

July First Quarter

M16

July 4, 2014. Beaver Meadow. 16” [F/4.5]. Clear, transparency above average to average. Dewpoint 8 deg. C. Slight fog on the field, does not seem to interfere. Moonset 00:35, astronomical twilight 03:35. Observations begun 00:30.
The nebulosity in M16 [see sketch] without a filter is pretty faint. Nicely framed by the Pentax XW40 at 45x. With the filter (OIII) the eagle shape is immediately apparent in the nebulosity, and the double lucida appears, as described by O’Meara, like the eyes of a flying ghost. Low power observations finished 01:05. 01:25. [M16] fits well into the field of 13 mm Ethos with OIII filter. Contour of the nebulosity is approximately the same as at low power. SQML 21.05 overhead and 20.85 in the area of M16. Medium-power observations finished 01:50. High-power observation of M16 finished 02:10.
Time 02:25. M92. At high power with the 8 mm Ethos the stars in M92 are resolved to the center. In the very center there is bright unresolved background. E of center there is a NNE-to-SSW line of stars. It is just beyond the bright central part, on the black background. Overall the cluster is framed by the Ethos well. A branch of stars runs SE and curves E in the outer halo. Another one runs N and curls sharply E then SE, and from there faint stars connect it to the tip of the previously described arm. A stubby arm runs SW.
M15. Time 03:00. M15 at low power [45x] has a distinctly warm tinge. It has an extensive halo and a sharp concentration in the middle. The core is positioned eccentrically in the off-round halo. There is darkness almost immediately to the E of the core, on which side the halo is flattened; it is round on all other sides. At the high power [230x with Ethos 8] there are many stars in the previously dark part of the halo, and the halo overall is distinctly irregular. There is a dark wedge intruding almost to the core from the W in the form of a sector without stars. The edges of this sector appear enhanced with the concentration of stars in the halo, and there are what seem to be two arms of stars pointing N and S. The E side of the halo is uniformly filled with stars, at a lower concentration but to the same radius of the halo. The warm tinge is preserved but more subdued; it appears that the very center is only slightly yellow, and many stars radiating toward the periphery are warm in color. However, at this magnification the coloration is subtle. The stars are resolved to the very center, although there is considerable bright background in the very center.
Time 03:20. M 73 at the low power is a small but well-isolated group of 4 stars in the form of a triangle with one star inside it. The two brightest stars form the small E side of the triangle. The S star of the two is the brightest. The triangle is pointed W and points at a bright field star many sizes of the asterism to the W. A fainter star pair is obliquely and more closely positioned to the S. To the E, at the same distance as the bright field star, is a triangle of equally bright stars that has a side equal to several sizes of the asterism, and this triangle points E. The entire distance between the bright star to the W and the triangle to the E occupies less than half of the Pentax XW40 field. At the high power the lucida in the SE corner is warmly tinged compared with the bluish-white three stars in the rest of the asterism. The star inside the triangle is slightly fainter than the other two bluish stars and is positioned close to the SW side of the triangle and closer to the W tip of the asterism.

Monday, July 7, 2014

June New Moon

M8

June 27, 2014. Beaver Meadow. 16”. Clear, transparency average to above average, seeing average to good. Warm but not too humid. Astronomical twilight 23:10, 03:20. SQM-L 21.21 mag/sq arcsec overhead, 20.80 in the area of M8.
M8 is obvious with the naked eye. Telescopic observation with the 40 mm Pentax and 13 and 8 mm Ethoses begun 00:30, finished 02:00. See sketch. Observed with OIII filter.
Time 02:25. M2 is compact, textured, and concentrated at the low power, 45x with Pentax XW40. At high power with 8 mm Ethos M2’s stars are resolved over the entire cluster except the very center, about or less than 10% of the characteristic diameter. The very center is textured with at least one star resolved close to the geometrical center. Cluster is well framed by the Ethos and had a slightly triangular appearance pointing W.
Time 02:45. The pair of the blazar 3C 454.3 (distance 7 Bly, peaking) with the nearby 13th-magnitude star is visible already at the low power as a nebulous spot. At the high power (225x) the pair is completely resolved, and the relative brightness of the star and the blazar alternates with the shifting of the gaze. It is possible that the incompletely resolved companion of the star contributes to the star’s brightness.