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RA: 19h 43m 59.33s
Dec: +17° 09′ 05.5″
Ch: MSA:1219, U2:162, SA:16
Ref: [arXiv:1009.1043], VizieR
Type: planetary nebula
Mag: B=?, V=?
Size: 0.29′ x 0.13′
The Necklace: equatorial and polar outflows from the binary central star of the new planetary nebula IPHASXJ194359.5+170901
"IPHASXJ194359.5+170901 was discovered as a new candidate PN from images of the IPHAS survey obtained on 2005 (Sabin et al. 2010)."
"IPHASXJ194359.5+170901 is a new high-excitation planetary nebula with remarkable characteristics. It consists of a knotty ring expanding at a speed of 28 km/s, and a fast collimated outflow in the form of faint lobes and caps along the direction perpendicular to the ring. The expansion speed of the polar caps is approx. 100 km/s, and their kinematical age is twice as large as the age of the ring."
"The morphology of the nebula is similar in the H-alpha and [O III] emission: it consists of a diffuse, elliptical or perhaps spindle-like inner body, whose brightest regions are in the form of a knotty elliptical ring with a long axis of about 13 arcsec. Along the orthogonal direction, faint emission traces a roughly-cylindrical structure ending in two slightly brighter, irregular “polar” caps at about 1 arcmin from the central star. As typical of this kind of structure (Gon¸calves et al. 2001), the ring’s knots and their faint outward tails, as well as the polar caps are most evident in the low-ionization [NII] emission. This striking [NII] morphology led to the object’s nickname, 'the Necklace Nebula' (Sabin et al. 2010)."
"Total size of the nebula, including the faint polar extensions, is considerable, 2.7 pc. The kinematical age of the ring would be 5000 years, and the maximum age of the polar caps would be 13000 years."
distance = 4.6 +/- 1.1 kpc.
An image of the Necklace Nebula was featured on APOD (2010 November 03).
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