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NGC 6984

NGC 6984
NGC 6984 imaged by the Hubble Space Telescope
Observation data (J2000 epoch)
ConstellationIndus
Right ascension20h 57m 53.987s[1]
Declination−51° 52′ 15.13″[1]
Redshift0.015386[1]
Heliocentric radial velocity4577 km/s[1]
Distance180 million ly[2]
Apparent magnitude (V)12.65[1]
Apparent magnitude (B)13.19[1]
Surface brightness22.82 mag/arcsec2[3]
magnitude (J)10.94[3]
magnitude (H)10.25[3]
magnitude (K)9.99[3]
Characteristics
TypeSpiral (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

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]

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]

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

References

  1. ^ a b c d e f g "Search Results for NGC 6984". Astronomical Database. SIMBAD. Retrieved 5 November 2013.
  2. ^ "Stellar explosions in NGC 6984". ESA/Hubble Picture of the Week. Retrieved 5 November 2013.
  3. ^ a b c d e f "NGC 6984 - Spiral Galaxy in Indus". thesky.com. The Sky LIVE. Retrieved 12 Sep 2024.
  4. ^ "NGC 6984". simbad.u-strasbg.fr. Retrieved 12 Sep 2024.
  5. ^ Seligman, Courtney. "NGC 6984". Celestial Atlas. Retrieved 22 August 2024.
  6. ^ "SN 2012im/2013ek: A Supernova Double Take in NGC 6984". SAO Astrophysics Data System (ADS). AAS Meeting #223, id.354.29. January 2014. Retrieved 12 Sep 2024.
  7. ^ "SN 2012im". Transient Name Server. IAU. Retrieved 22 August 2024.
  8. ^ "ATel #4300: PESSTO spectroscopic classification of optical transients".
  9. ^ "CBET 3607 : 20130728 : SUPERNOVAE 2012im AND 2013ek IN NGC 6984". Central Bureau for Astronomical Telegrams (CBET). Retrieved 12 Sep 2024.
  10. ^ "ATel #5225: A new SN suspect at the position of SNhunt142 discovered 1 year ago".
  11. ^ "SN 2013ek". Transient Name Server. IAU. Retrieved 22 August 2024.
  12. ^ "ATel #5227: Spectroscopic classification for PSN J20575390-5152245 with FLOYDS at Faulkes Telescope South".
  13. ^ "13505 Program Information".
  14. ^ Hubble Catches Stellar Explosions in NGC 6984, NASA, 13 November 2013, archived from the original on 21 November 2013
  • Media related to NGC 6984 at Wikimedia Commons


Quelle: https://en.wikipedia.org/wiki/NGC_6984