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RA: 07h 25m 34.72s
Dec: +29° 29′ 25.6″
Ch: MSA:130, U2:100, SA:5
Ref: SIMBAD, Corwin (2004)
Type: planetary nebula
Mag: B=14.48, V=14.85
Select a sketch and click the button to view
Synonyms: H II-316
Discovered in 1785 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "Two. sp-nf, distance 1', chevelure mixed. Both faint, small, equal, having a nucleus ." The second object is NGC 2372.
Lassell, W. (1854) Observations of the nebula of Orion, made at Valletta, with the twenty-foot equatorial. Memoirs R.A.S., 23, 53-62.
Sketched and described.
Photo index by Jim Lucyk: Sky&Tel. 2/86 p219, Sky&Tel. 7/82 p19, Astronomy mag. 2/84 p78.
The RNGC (Sulentic and Tifft 1973) notes that this is a 13.0 mag planetary nebula.
Houston writes: "Don't be misled by the double number; it's really only one object, though early observers saw it as two nearly touching and catalogued them separately. It looks similar to M76 in Perseus and like a miniature version of the Dumbbell ... the southwest section (NGC 2371) is the brighter half; the whole planetary is an easy object for an 8-inch scope. ... [photographs] show faint sections of an outer ring about 2' in diameter surrounding the planetary. Its brightest sections are at right angle to (rather than in line with) the nebula's two easily seen halves. I've never heard of anyone seeing this outer ring visually."
Houston notes that this nebula is about 1' in diameter and only of the 11th magnitude. The central star is quite easy, being about 12th mag. He writes that "amateurs will not readily be able to locate NGC 2371-2 without a 12.5-inch or larger telescope and an excellent night. My 4-inch fails to show it."
Listed by the Herschel Club, described as "mag estimated at 11.0, no separation evident between the two [NGC 2371 & NGC 2372], appears elongated, effect of separation improved by sweeping the field, off-white in colour. 6-inch, 48x & 96x."
Ken Reeves, in "SACNEWS On-line for February 1997", observing with a 10-inch f/4.5 scope, notes: NGC 2371 and NGC 2372 (07 25.6 +29 29) This planetary nebula contains two very bright spots with an NGC designation assigned to each spot. At 170X I saw this a very bright, pretty small, and very elongated NE/SW with the SW spot as the brighter one. I didn't see color at any power, and using the UHC filter made the object brighter but didn't bring out any more detail. To me, I envision this object as a donut cut in half with the two bright spots being the cut ends of the donut.
Hartung notes: "this interesting object appears like two round nebulae in contact in pa 65 deg, each rather less than 30 arcsec across and only moderately bright. Each has a brighter nucleus."
Tom Lorenzin, in the electronic version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "12.5M; 50" diameter; 2-part PL NEB oriented WNW-ESE with ESE part brighter; 1.75 degrees due N of Iota GEM."
Observer: Todd Gross; Your skill: Intermediate ; Date and UT of observation: 10/24/97 0800 GMT; Location & latitude: 22 miles west of Boston, Ma. 42.3N; Site classification: Suburban; Limiting magnitude (visual): 4 (estimated)4 (est) in vicinity of object; Seeing (1 to 10 - worst-best): 3; Moon up (phase?): Yes, 40%; Weather: Partly cloudy (high veil of cirrus clouds); Instrument: 16" Newtonian-dob w. 96/99% coatings f/4.59; Magnifications: 143x, 250x,310x; Filters used: UHC; Object: NGC 2371
This object is very close to the much brighter planetary nebula.. NGC 2392, the Eskimo nebula. Although this is fairly easily picked out at this aperture, it is much weaker than NGC 2392, which has a very high sfc. brightness. The view with and without the UHC filter was similar, although I viewed mostly with the UHC as it brought out more contrast. This planetary is double lobed, and odd shaped. It is a bit larger than 2392, and in fact, is about an arc minute wide. Best magnification with this high deck of cirrus clouds, and poor seeing conditions was at 250x.
Th Eastern part (lobe) of the nebula is triangular, with the base facing east, and the point facing west. Then from the south side of this triangle runs a bridge, comma shaped, to a round patch of nebulosity on the west side of the nebula. This comma shape, reminded me of the crescent nebula, but much smaller.
Observer: Todd Gross Your skill: Intermediate - Many years Date and UT of observation: 10/15/99 09:00GMT Location & latitude: 22 mi. West of Boston, Ma. 42.3N Site classification: Suburban Limiting magnitude(visual):approx.5.3 zenith,5.3 nr.object Seeing (1 to 10 - worst-best): 6-7 Moon up (phase?): Yes, thin crescent Weather: Clear Instrument: 18" f/4.2 fl=1925mm Newt Magnifications: 316X, 100x Filters used: none Object: NGC2371 Constellation: GEM Object data: PN Size(s): 44" Position: 7:26 +29:29 Magnitude: 11.2 Personal "rating": B/B+
Very interesting planetary, I think I have written up previously. This time , with no filter and 316x, a pretty double-planetary nebula with a central star, approx. 14.7 mag. which pops out particularly well with averted vision. No strong color. The two lobes (shaped freeform triangular) appear barely connected at the central star.. and seem more separate than similar and larger nebulas.. M76 and M27. At first glance at 100x I did mistake this as a double star, but didn't take much scrutiny to see that at least one lobe was nebulous, before I began raising magnification.
Observer: Yann POTHIER (France) Your skill: advanced (many years) Object: NGC 2371-2 (PK 189+19.1; PN G189.1+19.8; ARO 45) Category: planetary nebula Constellation: GEM Object data: Vmag=11.2; Bmag=13.0; 54x35"; type IIIa+VI; central star of Vmag=14.8 (Bmag=12.5); discovered by Herschel in 1785 (as a PN by Pease in 1917); ELCAT: [OIII, 496+501nm] = 9 x [Hbeta, 486nm]. RA/DE: 07h25.60m, +29°29.5' (2000.0) Date and UT of observation: 03 Janvier 1998, 01h45TU Location & latitude: La Clapiere Obs. (France, latN44 40 00, longE06 27 36) Site classification: rural, alt.1650m (5500ft) Limiting magnitude (visual in UMi): 6.31 with indirect vision 25% of the time Transparency (1 to 5 - best to worst): 1 Seeing (1 to 5 - best to worst): 4.5 (stellar stars until 72x) Moon up (phase?): no Instrument: Japanese Newtonian 4.25" (114mm), F/7.8 Magnification: 72-150x Filters used: -
Description: in 1989, I described it as "located at 72x, small nebula, quite faint, elongated", amazed to have found it because in a french reference, it was called a 8-inch object; nearly 10 years later in 1998: "very small PN, very faint, located at 72x/100x, elongated with two brighter lobes, about 58"x31" in a NE-SW axis, with a mag13 star in the SW lobe, no central star".
Observer: Yann POTHIER (France) Your skill: advanced (many years) Object: NGC 2371-2 (PK 189+19.1; PN G189.1+19.8; ARO 45) Category: planetary nebula Constellation: GEM Object data: Vmag=11.2; Bmag=13.0; 54x35"; type IIIa+VI; central star of Vmag=14.8 (Bmag=12.5); discovered by Herschel in 1785 (as a PN by Pease in 1917); ELCAT: [OIII, 496+501nm] = 9 x [Hbeta, 486nm]. RA/DE: 07h25.60m, +29°29.5' (2000.0) Date and UT of observation: 01 Janvier 1993, 03h30TU Location & latitude: La Clapiere Obs. (France, latN44 40 00, longE06 27 36) Site classification: rural, alt.1650m (5500ft) Limiting magnitude (visual in UMi): 6.0 Transparency (1 to 5 - best to worst): 1 Seeing (1 to 5 - best to worst): 2 Moon up (phase?): no Instrument: Meade SCT 8" (203mm), F/10 Magnification: 87-145x Filters used: OIII
Description: at 145x, medium sized PN, medium brightness, elongated (estimated to be 73"x36") in a NE-SW axis, with two brighter lobes at the ends; the SW lobe is brighter and contains a mag13 stellar knot (that is not weakened by the OIII so it's not a star, rather a nebular condensation); OIII geives an overall good contrast gain and gives a clearer view, better separating the 2 lobes; no central star; the nebula forms a triangle with 2 mag10.5 stars 8' to the WNW and SSW; a double of mag13+14 (20" to the NE) is at 2.2'NW.
Observer: Yann POTHIER (France) Your skill: advanced (many years) Object: NGC 2371-2 (PK 189+19.1; PN G189.1+19.8; ARO 45) Category: planetary nebula Constellation: GEM Object data: Vmag=11.2; Bmag=13.0; 54x35"; type IIIa+VI; central star of Vmag=14.8 (Bmag=12.5); discovered by Herschel in 1785 (as a PN by Pease in 1917); ELCAT: [OIII, 496+501nm] = 9 x [Hbeta, 486nm]. RA/DE: 07h25.60m, +29°29.5' (2000.0) Date and UT of observation: 01 Janvier 1993, 03h30TU Location & latitude: La Clapiere Obs. (France, latN44 40 00, longE06 27 36) Site classification: rural, alt.1650m (5500ft) Limiting magnitude (visual in UMi): 6.0 Transparency (1 to 5 - best to worst): 1 Seeing (1 to 5 - best to worst): 2 Moon up (phase?): no Instrument: Coulter 445mm/17.5" F/4.5 Magnification: 45-312x Filters used: OIII, UHC, prism
Description: at 312x, medium to large PN, bright, globaly oval shaped SW-NE, with quite sharp edges; 2 lobes are visible, _the NE one is 35"x24" in a NW-SE axis and contains in its SE half a brighter triangluar area, _the SW one is 38"x25", brighter than the first one and elongated in the same axis, and contains in its NW half a brighter circular knot (about diam.15") which has a stellar nucleus (still stellar with prism so it is not a star); the central star is easily visible in the middle area (of very weak surface brightness), quite dark around the star, of about mag14; the nebula is globaly 70"x40"; UHC has a small contrast gain and OIII a good one; already seen at 45x, elongated, small and nebulous, even without filter; a mag13 star is 1' to the WNW.
NGC 2371-2 Donald J. Ware:"You've probably heard of the Dumbell Nebula (M-27), and the Little Dumbell (M-76), but how about the Micro-Dumbell? You probably haven't because that's my name for this object. This planetary nebula (some authors say it is two line-of-sight planetaries) appears as two softly glowing grey puffs of light, seemingly touching. It is about 30"x12" in total extent, with the more western lobe appearing brighter. I think this faint object is one of the many fascinating gems found by those willing to delve into the deep sky, past the bright and splashy showpieces."
PK: 1' NW & SE sides are br ansae.
15cm - two halves not seen. *-like spot in center.
- obvious @ 50x. [OIII] makes dbl-lobes nature clr at this low power, the brtr SWrn lobe containing a consp *-like feature. 140x: lobe centers 45" apart, the f surround is 1'.2 diam. both lobes concen, but SWrn one much more so, sub*ar here, about as br as m12 * 4' N, which is brtr of un= pair in same pa as lobes but smlr sep. BS, 7Nov1988, Anderson Mesa.
25cm - not f. elong NE-SW, two patches. SW one brtr and more concen w/*ar nuc. NE patch has br center. not dk btwn patches.
30cm - nice pair. at 149x pair is oriented in pa45, approx circ outline. 50" diam, both parts about same size, but -71 is much brtr w/*ar cen. 238x: sep btwn not dk. -72 has occas *ing off center to NE.
Steve Coe, observing with a 13" f/5.6, notes: "Bright, large, elongated box shape at 100X. Higher powers bring out much structure. Using 200X on a night I rated 7/10, a central star couldbe held with direct vision. This planetary is grey at all powers. Going to 320X has this object appear as a figure 8 with a star involved, a dark lane cuts the "8" shape into two fairly equal pieces. I am certain this is why this planetary got two NGC numbers. [NGC 2371 & NGC 2372]"
Observer: Eric Honeycutt Your skills: Intermediate (some years) Date/time of observation: 10/14-15; 0406 EDT Location of site: Bladen Lakes State Forest (Lat 35, Elev 400+) Site classification: Rural Sky darkness: 6.9 Limiting magnitude Seeing: 5 10-1 Seeing Scale (1 best) Moon presence: None - moon not in sky Instrument: 22",f/4.1, Dob Magnification: 288x, 576x Filter(s): Object(s): NGC 2371-2 Category: Planetary nebula. Class: Constellation: GEM
Description: 2 lobes with a easily seen division between the lobes. Northern lobe is much brighter. Central star is apparent between the sections. Lobes are mottled. The snakes of Medusa's 'hair' are evident at higher powers as a filamentary structure with averted vision. Intricate detail is seen in moments of steady seeing. Great Pn!
Observer: Steve Coe; Your skills: Advanced (many years); Date/time of observation: 12 Feb 99; Location of site: Salome, Arizona USA (Lat +34, Elev 3000 ft); Site classification: Rural; Sky darkness: 8 1-10 Scale (10 best); Seeing: 7 1-10 Seeing Scale (10 best); Moon presence: None - moon not in sky; Instrument: 13" f/5.6 Newtonian on Bigfoot German EQ ; Magnification: 100X, 220X; Filter(s): none; Object(s): NGC 2371;
Description: NGC 2371 and 2372 at 100X in the 13" f/5.6 it is easily seen as double even at this low power. 220X shows it as bright, small, elongated 2X1 in PA 60. The west end of this nebula has a bright, non-stellar blob that is obvious. The central star is within a thin dark lane that seperates the two parts of this double-lobed nebula. The star is only seen in short glimpses. Adding the UHC filter makes the nebula stand out much better and the faint outer nebulosity is now seen easily with averted vision. This tenuous outer haze is more easily seen on the north side of the main nebula. Raising the power to 330X will hold the central star about 30% of the time. There is no more detail seen at high power, but it is an excellent view of all the detail within this nebula. --
[amastro] posting, Sat Nov 25, 2006
82" telescope, McDonald Observatory near Fort Davis, Texas, USA
f/13.7, 35mm Televue Panoptic (5' fov, 812x)
At this aperture this is a large, bright object, bipolar, somewhat elongated, with an obvious central star. The dark lane I see in smaller telescopes is not particularly dark at all in the 82", there is some nebulosity there. I forgot to look for the "polar caps" that show in deep photos about 1 diameter off the ends of the axis of the dark lane, I'll bet they were there... :-(
Alldays (22.50S, 20.12E, 770m).
12-inch f/10 SCT (76x, 218x, 346x)
Two circular patches of nebulosity straddling its 13.3 magnitude central star. Lobes of nebulosity appeared almost to touch averted vision necessary for central star. The south western lob is brighter. This is very unique. I use a 0111 filter and was amaze to the nebulosity extended on the edges of the two lobs as well as between the two. The central star is seen easy with care.
Observing site: Little Bennett Regional Park
[7h 25m 36s, 29° 29m 0s] A pair of faint blotches. WikiSky shows a complete ring. Interesting object.
Sky Conditions:The fainter parts of the Milky Way are barely visible.Haziness only visible on the horizon.Atmosphere stable with little interference.
The two planetary nebulae is joined together with its lobes aligned in an NE-SW direction which takes the form of the shape of a peanut.The SW lobes is brighter and more concentrated and has a reddish green nucleus.The central star in this nebula is just on the brink of visibility.This planetary nebula measures 2.2'*0.7'.
The Messier objects
The Bennett objects
The Caldwell list
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