LMC-N49 = PKS 0525-66 = SNR B0525-66.1 = DEM L 190

05 26 01.9 -66 05 07; Dor
Size 1.2’x1.0′

24″ (4/11/08 – Magellan Observatory, Australia): this amazing object is the brightest supernova in the LMC and it harbors a powerful pulsar. At 260x unfiltered, it appeared as a bright “U” shape just under 1′ in diameter with the center of the “U” at the east end (base oriented SW-NE) and open on the west side. The interior is much dimmer than the rim. The brightest spot is right at the east end, though the rim is much brighter and better defined along the entire base. The northern bar of the “U” side is fainter and oriented NW-SE with some haze spreading into the interior. The southern bar is brighter and narrower. A UHC filter increased the contrast and there were hints of more complex filamentary structure. This SNR is located 3.8′ ENE of mag 9.0 HD 36257 and 19′ NW of the gorgeous cluster NGC 1978. Open cluster S-L 463, which appears as a very small knot attached to a star, is located 2.4′ NE.

A broad, scattered stream of brighter stars (association LH 53) extends from a few arcmin west and east of the supernova in a roughly southwest orientation, merging into the northwest side of NGC 1948.

Notes: Robert Innes discovered N49 on a photograph taken with the 10-inch Franklin-Adams camera of the Johannesburg (Union) Observatory. It was listed in the 1924 “Catalogue of Clusters and Nebulae Near the Large Magellanic Cloud” as a “Irregular small nebula, nf [CPD] -66° 412.” See http://articles.adsabs.harvard.edu/full/1924CiUO…61..243I

Annie Jump Cannon rediscovered N49 in 1933 on a plate taken with the 24″ Bruce telescope in Bloemfontein, South Africa (Harvard Bulletin 891, #20 in table of Gaseous Nebulae in the Magellanic Clouds”).

N49 was one of the first three confirmed Supernova Remnants in the LMC (along with N63A and N132D). On the basis of structure, Mathewson, Healey and Westerlund concluded N49 was a SNR in 1964 and confirmed in 1966 based on spectra (paper below).