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RA: 16h 44m 29.491s
Dec: +23° 47′ 59.68″
Ch: MSA:1204, U2:156, SA:8
Type: planetary nebula
Mag: B=12.3, V=10.2
In the 5th edition of Webb's Celestial Objects for Common Telescopes it is described as "planetary nebula, 8' in diameter; discovered by Struve. Very bright. d'Arrest = 8th mag; small, not sharply defined; exactly like a star out of focus, bearing power well. 111x of 5.5-inch showed a glow round it. E. of Rosse, intense blue. Se. thought it resolved with a power of 1500; but the spectroscope shows it gaseous."
Doig, P. (1925) Notes on the nebulae and clusters in Webb's 'Celestial Objects for Common Telescopes' (Sixth edition, Vol.ii). Part II. M.N.R.A.S., 35(8), 280.
Photo Index by Jim Lucyk: Astronomy mag. 6/86 p106, Deep Sky #6 Sp84 p15, Deep Sky #24 Fa88 p10, 12.
The RNGC (Sulentic and Tifft 1973) notes that this is a 9.5 mag planetary nebula.
Houston writes: "To me this small planetary looks only about 13x8 arcseconds in size, and 100x made identification certain." Its magnitude has been estimated as 8.5. He notes that it is within easy reach of a 4-inch. Houston notes that the fine double star Struve 2094 lies quarter of a degree south (mag 7.4,7.7 1.2" PA 76°).
Hartung notes: "This beautiful bluish nebula is in attractive contrast with a number of field stars; it is round with well-defined edges, about 20 arcsec across . . an excellent object for small apertures."
John Bortle (Webb Society Quarterly Journal, January 1976) using 10x50 binoculars, estimates the visual magnitude as 8.8.
Observer: Adam Albino Your skills: Intermediate (some years) Date/time of observation: 5/20/98 LMT=9:36, UT=2:36 Location of site: Norwell, MA (Lat 42m 16.9s, Elev ) Site classification: Exurban Sky darkness: 5.5 Limiting magnitude Seeing: 7 1-10 Seeing Scale (10 best) Moon presence: None - moon not in sky Instrument: 8" f/10 Ultima 8 PEC SCT - 80mm Mak f/10 Magnification: 45, 96,169,406 Filter(s): UHC Object(s): NGC 6210 Category: Planetary nebula. Constellation: Her Data: mag 9.7 size 20"x13" Position: RA 16:44.5 DEC 23:49
Description: "A small bright planetary that was easy in the 8" and 80mm. Not quite stellar, but seemingly like a slightly out of focus star. Round, with little detail, and a slight "neon" glow that I find most planetary's to have. I noticed at 169 and 406X a bit of oblong shape to the south east - very faint (?). Several similar mag stars are in the same FOV which makes identification easy."
Observer: Todd Gross
Your skill: Intermediate - Many years
Date and UT of observation: 3/09/99 09:00 GMT
Location & latitude: 22 mi. West of Boston, Ma. 42.3N
Site classification: Suburban
Limiting magnitude (visual): approx. 4.7 zenith
Seeing (1 to 10 - worst-best): about 3
Moon up (phase?): Yes, last 1/4 (just over)
Weather: Crystal Clear
Instrument: C9.25" SCT f/10 f.l.2350
Magnifications: 123 & 235x
Filters used: none
Object: NGC6572 & NGC6210
Constellations: Ophiuchus and Hercules
Object data: Planetaries
Size(s): 13" 6572, 17" 6210
Magnitudes: Both near 9
Personal "rating" (at this aperture, and sky condition): B/B-
These little planetaries are striking for their color. I first viewed NGC6572 through this 9.25" SCT and at lower magnification, it looked like a fuzzy blue star. At 235x, a very bright, striking blue (cyan) fuzzball brightest in the center. I then moved to 6210 and made a comparison. NGC6210 is almost identical. It is slightly larger, a bit more diffuse (slightly) and a bit less striking in surface brightness and color. However, the two could be twins! As you can tell I liked 6572 a bit more as one of the most colorful objects I have seen at this aperture.
Boston Meteorologist Todd Gross
Observer: John Callender
Instrument: 8-inch Dobsonian reflector Location: Carpinteria, CA, USA
Light pollution: light Transparency: good Seeing: fair
Time: Sun Jun 29 09:00:00 1997 UT Obs. no.: 166
It required careful starhopping in a star-poor region (I really need a Uranometria atlas!). Once I was there, though, it was easy to see this planetary at 49x, though it was hard to be sure that it was nonstellar. At 244x, though, it was clearly a small, round, uniform patch. I believed I could detect a slight greenish tint.
(PK43+37.1) Mag=8.8. Hercules: 16h, 44.5m; +23° 49' A large planetary (uneven shape: possibly approximately an arcminute long by somewhere from 8-14 arcseconds in width), featuring surprisingly- high surface brightness. Dr. Jack Marling calculates a modern visual magnitude figure of 8.8; our Waldee-Wood EYEPIECE 2.0 or REDSCOPE 4.03 programs then determine from that measurement an approximate surface brightness of almost 6th magnitude per square arcminute of area! We observed it clearly when it was elevated only about 40 degrees above the horizon in a sky with a naked-eye stellar magnitude limit of about 5.2. At 50x, the shape was evident. With 200x, the presence of an outer halo was suspected, which was -- amazingly -- perfectly evident with a 2.5mm ocular, providing over 400x! Usually nebular objects disappear in an 8" scope with such high magnification: this object bears scrutiny!
Tom Lorenzin, in the e-version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "9.7M; 18" diameter; bright blue disc with crisp edges makes seeing 12.5M center star difficult; a few minutes NW of 7.5M star (SAO 84574); use high-x and N-filter."
7cm - vbr & sub*ar @ 30x just recog for being invis w/direct vis whereas *s
of same brtness remain. 110x: vsm and exhisfcbr. cen * seems brtr, *ar.
BS, 26Apr1993, Anderson Mesa.
15cm - dull. extremely br @ 38x. 234x: just a plain disk, no detail or cen *.
an interesting kind of blue. located at apex of br triangle of *s. HM,
- br & non*ar @ 50x. 165x/295x: oval in pa100, outer vf collar surrounds
much brtr disc w/in, which seems to become somewhat fntr inside itself
[schematic of this on card]. no cen *. ADS10184 in fld SSW. BS,
29Jun1989, Anderson Mesa.
25cm - no details, bluish oval. recog at 47x.
- 190x/280x: elong pa90, 25"x15", poss aureole 40" diam, circ. cen * susp
or sharp *ar center. faintly greenish. BS, 23May1982, Anderson Mesa.
30cm - 297x: br, sm. elong E-W. bluish. no features.
Observing site: Little Tycho Observatory
[16h 44m 30s, 23° 49m 0s] A round, slightly fuzzy at the edges disc. It's bright, small, and pastel blue.
The Messier objects
The Bennett objects
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