BETA SAÚDE
NGC 6984
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| 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 | |
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).[1] 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.[4]
Supernovae
NGC 6984 is notable for having been the host of two supernovae which occurred in the same location (< 0.4 arcsec),[5] about 1 year apart: SN 2012im (Type Ic, mag. 18.9), first known as SNhunt142,[6][7][8][9] and SN 2013ek (Type Ib/c, mag. 16.9).[10][11] Hubble Space Telescope observations were initiated by Dr. Dan Milisavljevic.[12] 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."[13]
Gallery
The galaxy NGC 6984, an elegant spiral galaxy in the constellation Indus roughly 200 million light-years away from Earth.
References
- 1 2 3 4 5 6 7 8 "NGC 6984". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 13 August 2026.
- ↑ "Stellar explosions in NGC 6984". ESA/Hubble Picture of the Week. Retrieved 5 November 2013.
- 1 2 3 4 5 6 "NGC 6984 - Spiral Galaxy in Indus". thesky.com. The Sky LIVE. Retrieved 12 Sep 2024.
- ↑ Seligman, Courtney. "NGC 6984". Celestial Atlas. Retrieved 22 August 2024.
- ↑ Milisavljevic, Dan; Drout, M.; Margutti, R.; Soderberg, A. M.; Fesen, R. A.; Parker, S.; Brimacombe, J.; Sanders, N.; Kamble, A.; Berger, E.; Kirshner, R. P.; Drake, A. J.; Howerton, S.; Hsiao, E.; Morrell, N. (January 2014). "SN 2012im/2013ek: A Supernova Double Take in NGC 6984". SAO Astrophysics Data System (ADS). 223. AAS Meeting #223, id.354.29. Bibcode:2014AAS...22335429M. Retrieved 12 Sep 2024.
- ↑ Cellier-Holzem, Flora; Smartt, S. J.; Inserra, C.; Fraser, M.; Wright, D.; Young, D. R.; Smith, K. W.; Pastorello, A.; Valenti, S.; Benetti, S.; Taubenberger, S.; Sullivan, M.; Gal-Yam, A.; Yaron, O.; Howerton, S.; Baltay, C.; Ellman, N.; Hadjiyska, E.; McKinnon, R.; Rabinowitz, D.; Feindt, U.; Kowalski, M.; Nugent, P. (2012). "PESSTO spectroscopic classification of optical transients". The Astronomer's Telegram. 4300: 1. Bibcode:2012ATel.4300....1C.
- ↑ Howerton, S.; Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, M.; McNaught, R. H.; Beshore, E. C.; Larson, S. M.; Christensen, E.; Miller, P.; Roche, P.; Tripp, A.; Miles, R.; Holmes, R.; Foglia, S.; Buzzi, L.; Cellier-Holzem, F.; Milisavljevic, D.; Fesen, R.; Pickering, T.; Kotze, P.; Drout, M.; Margutti, R.; Soderberg, A. (2013). "Supernovae 2012im and 2013ek in NGC 6984". Central Bureau Electronic Telegrams (3607): 1. Bibcode:2013CBET.3607....1H.
- ↑ Parker, Stu; Bock, Greg; Marples, Peter; Drescher, Colin; Pearl, Patrick; Downs, Brendan (2013). "A new SN suspect at the position of SNhunt142 discovered 1 year ago". The Astronomer's Telegram. 5225: 1. Bibcode:2013ATel.5225....1P.
- ↑ "SN 2012im". Transient Name Server. IAU. Retrieved 22 August 2024.
- ↑ Valenti, S.; Sand, D.; Howell, D. A.; Graham, M. L.; Parrent, J. T. (2013). "Spectroscopic classification for PSN J20575390-5152245 with FLOYDS at Faulkes Telescope South". The Astronomer's Telegram. 5227: 1. Bibcode:2013ATel.5227....1V.
- ↑ "SN 2013ek". Transient Name Server. IAU. Retrieved 22 August 2024.
- ↑ "13505 Program Information".
- ↑ Hubble Catches Stellar Explosions in NGC 6984, NASA, 13 November 2013, archived from the original on 21 November 2013
External links
Media related to NGC 6984 at Wikimedia Commons
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