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RA: 07h 41m 54.91s
Dec: −18° 12′ 29.7″
Ch: MSA:319, U2:319, SA:12
Type: planetary nebula
Mag: B=18.9, V=?
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Synonyms: H IV-064
Discovered in 1790 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "a beautiful planetary nebula, of a considerably degree of brightness; not very well defined, about 12 or 15 arcseconds diameter."
Observed by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "an object which, owing to general bad definition to-night, and not being able to follow beyond its transit (being north of zenith), I could not perfectly make out. Certainly not a star; but if a planetary nebula, it is one of the less sharply defined ones."
In the 5th edition of Webb's Celestial Objects for Common Telescopes it is described as "planetary nebula, bright, pale bluish white. At 64x, like a dull 8th mag star; with more power, small, brilliant, undefined, surrounded with a little very faint haziness. In a glorious neighbourhood. E. of Rosse, a red star 9-10th mag following."
Lassell, W. (1854) Observations of the nebula of Orion, made at Valletta, with the twenty-foot equatorial. Memoirs R.A.S., 23, 53-62.
Doig, P. (1925) Notes on the nebulae and clusters in Webb's 'Celestial Objects for Common Telescopes' (Sixth edition, Vol.ii). Part I. M.N.R.A.S., 35(5), 159.
Terzian Y (1980) Q.J. R.astr.Soc vol 21, p82-92 [09.16.1] notes that this planetary shows multiple shell structure. He notes that the inner core is expanding faster than the outer halo by a velocity difference of a factor of about 2. Different shell ejections separated in time by about 10 000 years is a possibility. Minkowski has said for NGC 2440 'it is an example of an object so complicated it defies description'. " Terzian notes that it is considered to be a proto-planetary or very young planetary nebula. It is an infrared source, indicating the presence of dust in the envelope.
Photo Index by Jim Lucyk: Sky&Tel. 10/69 p227 (sketch).
!! vB, pS, DN surrounded by Saturn-like ring E 50deg, the whole involved in oval E 35deg."
The RNGC (Sulentic and Tifft 1973) notes that this is a 11.5 mag planetary nebula.
Listed by the Herschel Club, described as "stands out well, greenish tint, circular, found easily. 8-inch, 48x."
William P. Clarke (San Diego, California, USA) writes in The Webb Society Nebulae and Clusters Section Report No. 11, January 1993: "Looks like a small spiral galaxy at low power. Two elongated 'nuclei' are evident; these are parallel and extended in PA 60 degrees. Two smaller condensations appear at each end. The outer envelope is much fainter and is about 1' long, extending SW-NE. A small star lies at the NE end. Very high contrast with OIII filter; much dimmer with H-beta. (21-inch f/20, x350)"
Observer: Yann POTHIER (France) Your skill: advanced (many years) Object: NGC 2440 (PK 234+02.1; PN G234.8+02.4; ARO 47; Sa 2-14; bat nebula) Category: planetary nebula Constellation: PUP Object data: Vmag=9.4; Bmag=10.8; 54"x22"; type V+III; central star of Vmag=18.9; discovered by Herschel in 1790; ELCAT: [OIII, 496+501nm] = 20 x [Hbeta, 486nm]. RA/DE: 07h41.88m, -18°12.5' (2000.0) Date and UT of observation: 02 January 1995, 00h30UT 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): 3 Moon up (phase?): no Instrument: Coulter 445mm/17.5" F/4.5 Magnification: 312x Filters used: OIII, UHC
Description: at 312x, medium sized PN, very bright, oval SW-NE, about 69"x38", with ill defined adges; brighter towards the center, very small and bright nucleus (smaller than 8"); a plume or elongated extension leaves the nucleus in a ENE direction (28"x9"); UHC provides a good contrast gain and OIII a very good one; at low powers, a bluish tint is obvious; a mag14 star is 20" from the S edge; a mag8.5 star is 4' to the E.
Observer: Yann POTHIER (France) Your skill: advanced (many years) Object: NGC 2440 (PK 234+02.1; PN G234.8+02.4; ARO 47; Sa 2-14; bat nebula) Category: planetary nebula Constellation: PUP Object data: Vmag=9.4; Bmag=10.8; 54"x22"; type V+III; central star of Vmag=18.9; discovered by Herschel in 1790; ELCAT: [OIII, 496+501nm] = 20 x [Hbeta, 486nm]. RA/DE: 07h41.88m, -18°12.5' (2000.0) Date and UT of observation: 15 February 1991, evening 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): ? Moon up (phase?): no Instrument: Japanese Newtonian 4.25" (114mm), F/7.8 Magnification: 36-180x Filters used: prism
Description: found with prism at 36x as a stellar spectrum, of medium brightness; at 72x, somewhat nebulous with a star at 5'E; small and brighter central area with faint and small extensions melting gradually with the background sky; at 180x, large and irregularly shaped; be careful not to mistake the central brighter zone with a potential central star [that is easily seen only on HST images].
Tom Lorenzin, in the electronic version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "11.5M; 20" diameter core with 50" diameter outer envelope; tiny li'l thang! 1 degree NNE of cluster N2432."
Donald J. Ware:"This planetary nebula appears as an out of focus star, about 20" in diameter, with a bright center fading to the edges. No central star was seen in this blue-green nebula."
Steve Coe, observing with a 13" f/5.6, notes: "Bright, pretty large, much brighter in the middle, elongated 3X1 in PA 30 at 270X. The central star will become stellar in moments of good seeing but most of the time it is just a bright area in the center of this planetary. Averted vision will about double the size of the nebula. It was immediately recognized as non-stellar at 100X. This nebula is a nice lime green at all powers. Sentinel 13" 8/10--100X, found easily, pretty bright, pretty large, elongated 1.5 X 1 in PA 45, 220X--pretty suddenly much brighter middle, edges fuzzy, not well defined central bright spot is never stellar. 330X--amazing detail in bright central section, looks turbulent, several bright areas interconnected, averted vision makes it elongate."
Observer: Steve Coe Your skills: Advanced (many years) Date/time of observation: 16 April 1999 Location of site: Sentinel Star Gaze, AZ (Lat 45 n, Elev 100m) Site classification: Rural Sky darkness: Very transparent Seeing: Very good Moon presence: None - moon not in sky Instrument: 13" f/5.6 Newt Magnification: 100x, 330x Filter(s): None. Object(s): NGC 2440 Category: Planetary nebula. Class: 5+3 Constellation: Pup Data: mag 10.8 14.24m*; size 74"x42" Position: 074155.37 -181231.4 Description: Sentinel Star Gaze 99 - Big Success --
Well, after a couple of years having to deal with poor weather for the Sentinel Star Gaze, this year decided to really show off. A.J. Crayon and I made it out of Phoenix about 2:00 PM on Friday, April 16. This day also turns out to be my 50th birthday, a fact which has yet to sink in completely. I am, after all, only 23 years old in my head.
We made it to the tiny Arizona town of Sentinel and a short trip over the railroad tracks and down a dirt road to a big flat spot in the desert. Several other astronomers are showing up at about the same time and by the time it gets dark we have 8 scopes and fewer and fewer clouds...
Once it is good and dark, I can see that the seeing is even pretty good to a dark southern horizon, so I decide to chase some objects in the far south. First is NGC 2440, a planetary nebula in Puppis. It is obviously a planetary, even at 100X, and it is in the field of view of a nice orange star and delicate triple. Going to 330X it is pretty bright, pretty small, somewhat brighter in the middle and elongated 1.8x1 in PA 60. Averted vision does two things for this fine planetary, first it doubles the size and also brings out a dark marking across the middle of the nebulosity... [More to come!]
Observing site: Pinnacles overlook
[7h 41m 54s, -18° 13' 0"] Like a fuzzy, our of focus star at low power (115x, 30mm) but mottled at high power (246x, 12.5), with a hint of a central star. An interesting object. Burnham reports the central star is 16th mv, so I probably didn't see it.
Sky Conditions:The fainter parts of the Milky Way are barely visible.Haziness only visible on the horizon.Atmosphere stable with little interference.
This planetary nebula's oval like shape is clearly seen which looks like an albino at both magnification of 167*and 214*.However this nebula's albino shape takes form at 214* while by observing this planetary nebula at a low magnification of 57*and 75*I have found that this nebula looks like an out of focus star.At both 167*and 214*this nebula has a bluish white structure.This planetary nebula measures 1.4'*0.4'.The nucleus of this planetary nebula grows brighter compared to the far outskirts of this nebula.
The Messier objects
The Bennett objects
The Caldwell list
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