NGC 6984

NGC 6984 is a barred spiral galaxy located 180 million light years away in the constellation Indus. It is a Type II Seyfert galaxy, a type of active galactic nucleus (AGN).^[4] It is situated south of the celestial equator, and is visible with the help of a telescope having an aperture of 10 inches (250 mm) or more.^[3] It was discovered on 8 July 1834 by British astronomer John Herschel.^[5]

NGC 6984
NGC 6984 imaged by the Hubble Space Telescope
Observation data (J2000 epoch)
Constellation	Indus
Right ascension	20h 57m 53.987s[1]
Declination	−51° 52′ 15.13″[1]
Redshift	0.015386[1]
Heliocentric radial velocity	4577 km/s[1]
Distance	180 million ly[2]
Apparent magnitude (V)	12.65[1]
Apparent magnitude (B)	13.19[1]
Surface brightness	22.82 mag/arcsec2[3]
magnitude (J)	10.94[3]
magnitude (H)	10.25[3]
magnitude (K)	9.99[3]
Characteristics
Type	Spiral (SAc)[3]
Apparent size (V)	1.403 x 1.038 arcmin[1]
Other designations
IRAS 20543-5203, 2MASX J20575398-5152151, PGC 65798, AM 2054-520, APMBGC 235+046+104, ISOSS J20578-5152, SGC 205419-5203.8, ESO 235- G 020

Supernovae

NGC 6984 is notable for having been the host of two supernovae which occurred in the same location (< 0.4 arcsec),^[6] about 1 year apart: SN 2012im (type Ic, mag. 18.9),^[7] first known as SNhunt142,^[8][9][10] and SN 2013ek (type Ib/c, mag. 16.9).^[11][12] Hubble Space Telescope observations were initiated by Dr. Dan Milisavljevic.^[13] NASA's press release about SN 2013ek said:

"It is so close to where SN 2012im was spotted that the two events are thought to be linked; the chance of two completely independent supernovae so close together and of the same class exploding within one year of one another is a very unlikely event. It was initially suggested that SN 2013ek may in fact be SN 2012im flaring up again, but further observations support the idea that they are separate supernovae — although they may be closely related in some as-yet-unknown way."^[14]

Gallery

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  The galaxy NGC 6984, an elegant spiral galaxy in the constellation Indus roughly 200 million light-years away from Earth.