NGC 6984: Difference between revisions
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{{Short description|Spiral galaxy in the constellation Indus}} |
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{{Sky|20|57|53.987|-|51|52|15.13}} |
{{Sky|20|57|53.987|-|51|52|15.13}} |
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{{Infobox galaxy |
{{Infobox galaxy |
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| name = NGC 6984 |
| name = [[New General Catalogue|NGC]] 6984 |
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| image = |
| image = Stellar explosions in NGC 6984.jpg |
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| caption = NGC 6984 |
| caption = NGC 6984 imaged by the [[Hubble Space Telescope]] |
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| credit = ESA/Hubble & NASA |
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| epoch = [[J2000]] |
| epoch = [[J2000]] |
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| pronounce = |
| pronounce = |
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| constellation name = |
| constellation name = [[Indus (constellation)|Indus]] |
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| ra = {{RA|20|57|53.987}}<ref name=simbad>{{cite web|title=Search Results for NGC 6984|url=http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=NGC+6984|work=Astronomical Database|publisher=SIMBAD| |
| ra = {{RA|20|57|53.987}}<ref name=simbad>{{cite web|title=Search Results for NGC 6984|url=http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=NGC+6984|work=Astronomical Database|publisher=[[SIMBAD]]|access-date=5 November 2013}}</ref> |
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| dec = {{DEC|-51|52|15.13}}<ref name=simbad/> |
| dec = {{DEC|-51|52|15.13}}<ref name=simbad/> |
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| z = 0.015386<ref name=simbad/> |
| z = 0.015386<ref name=simbad/> |
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| h_radial_v = 4577 |
| h_radial_v = 4577 km/s<ref name=simbad/> |
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| gal_v = |
| gal_v = |
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| dist_ly = 180 million [[light year|ly]]<ref name=esahubble>{{cite news|title=Stellar explosions in NGC 6984|url=http://www.spacetelescope.org/images/potw1344a/| |
| dist_ly = 180 million [[light year|ly]]<ref name=esahubble>{{cite news|title=Stellar explosions in NGC 6984|url=http://www.spacetelescope.org/images/potw1344a/|access-date=5 November 2013|newspaper=ESA/Hubble Picture of the Week}}</ref> |
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| group_cluster = |
| group_cluster = |
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⚫ | |||
| mass = |
| mass = |
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| mass_light_ratio = |
| mass_light_ratio = |
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| appmag_b = 13.19<ref name=simbad/> |
| appmag_b = 13.19<ref name=simbad/> |
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| absmag_v = |
| absmag_v = |
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| mag_j = 10.94<ref name="TheSky"/> |
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| mag_h = 10.25<ref name="TheSky"/> |
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| mag_k = 9.99<ref name="TheSky"/> |
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| sbrightness = 22.82 mag/arcsec<sup>2</sup><ref name="TheSky"/> |
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⚫ | |||
| size_v = 1.403 x 1.038 arcmin<ref name=simbad/> |
| size_v = 1.403 x 1.038 arcmin<ref name=simbad/> |
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| notes = |
| notes = |
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| names = |
| names = {{ odlist | 2MASX= J20575398-5152151 | IRAS= 20543-5203 | PGC= 65798}}, AM 2054-520, APMBGC 235+046+104, ISOSS J20578-5152, SGC 205419-5203.8, ESO 235- G 020 |
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| references = |
| references = |
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}} |
}} |
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'''NGC 6984''' is a [[spiral galaxy]] located 180 million light years away. |
'''NGC 6984''' is a [[barred spiral galaxy]] located 180 million light years away in the constellation [[Indus (constellation)|Indus]]. It is a Type II [[Seyfert galaxy]], a type of [[Active galactic nucleus]] (AGN).<ref>{{cite web |
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|url=https://simbad.u-strasbg.fr/simbad/sim-id?Ident=NGC+6984 |
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|website=simbad.u-strasbg.fr |
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|title=NGC 6984 |
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|access-date=12 Sep 2024}}</ref> 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.<ref name="TheSky">{{cite web |url=https://theskylive.com/sky/deepsky/ngc6984-object |
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|website=thesky.com |
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|title=NGC 6984 - Spiral Galaxy in Indus |
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|publisher=The Sky LIVE |
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|access-date=12 Sep 2024}}</ref> |
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It was discovered on 8 July 1834 by [[United_Kingdom|British]] astronomer [[John Herschel]].<ref name="selig">{{cite web | url = https://cseligman.com/text/atlas/ngc69a.htm#6984 | title = NGC{{nbsp}}6984 | last = Seligman | first = Courtney | website = Celestial Atlas | access-date = 22 August 2024 }}</ref> |
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== Supernovae == |
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It is known for having been the host of two recent supernovae: one in 2012 first known as SNhunt142<ref name="SNhunt">http://www.astronomerstelegram.org/?read=4300</ref> (later designated SN 2012im<ref name="CBET">http://www.cbat.eps.harvard.edu/iau/cbet/003600/CBET003607.txt</ref>), and one in 2013 known as SN 2013ek. The first was a Type Ic<ref name="ATEL_BOSS">http://www.astronomerstelegram.org/?read=5225</ref> and the second was a Type Ib/c.<ref name="ATEL_Valenti">http://www.astronomerstelegram.org/?read=5227</ref> HST observations were initiated by Dr. Dan Milisavljevic.<ref name="Milisavljevic">http://www.stsci.edu/cgi-bin/get-proposal-info?id=13505&observatory=HST</ref> |
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NGC 6984 is notable for having been the host of two [[supernova]]e which occurred in the same location (< 0.4 arcsec),<ref> |
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[http://www.nasa.gov/content/goddard/stellar-explosions-in-ngc-6984/#.UoOpbJTXiBM NASA's press release] about SN 2013ek said: |
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{{cite web |url=https://ui.adsabs.harvard.edu/abs/2014AAS...22335429M/abstract |
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|title=SN 2012im/2013ek: A Supernova Double Take in NGC 6984 |
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|work=SAO Astrophysics Data System (ADS) |
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|publisher=AAS Meeting #223, id.354.29 |
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|date=January 2014 |
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|access-date=12 Sep 2024}}</ref> about 1 year apart: SN 2012im ([[Type_Ib_and_Ic_supernovae|type{{nbsp}}Ic]], mag.{{nbsp}}18.9),<ref>{{cite web | website=Transient Name Server | title=SN{{nbsp}}2012im | url=https://www.wis-tns.org/object/2012im |publisher = [[International_Astronomical_Union|IAU]] | access-date=22 August 2024}}</ref> first known as SNhunt142,<ref name="SNhunt">{{Cite web|url=http://www.astronomerstelegram.org/?read=4300|title=ATel #4300: PESSTO spectroscopic classification of optical transients}}</ref><ref name="CBET"> {{cite web |url=http://www.cbat.eps.harvard.edu/cbet/003600/CBET003607.txt |
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|title=CBET 3607 : 20130728 : SUPERNOVAE 2012im AND 2013ek IN NGC 6984 |
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|publisher=Central Bureau for Astronomical Telegrams (CBET) |
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|url-access=subscription |
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|access-date=12 Sep 2024}}</ref><ref name="ATEL_BOSS">{{Cite web|url=http://www.astronomerstelegram.org/?read=5225|title=ATel #5225: A new SN suspect at the position of SNhunt142 discovered 1 year ago}}</ref> and SN{{nbsp}}2013ek (type{{nbsp}}Ib/c, mag.{{nbsp}}16.9).<ref>{{cite web | website=Transient Name Server | title=SN{{nbsp}}2013ek | url=https://www.wis-tns.org/object/2013ek | publisher = [[International_Astronomical_Union|IAU]] | access-date=22 August 2024}}</ref><ref name="ATEL_Valenti">{{Cite web|url=http://www.astronomerstelegram.org/?read=5227|title=ATel #5227: Spectroscopic classification for PSN J20575390-5152245 with FLOYDS at Faulkes Telescope South}}</ref> [[Hubble Space Telescope]] observations were initiated by Dr. Dan Milisavljevic.<ref name="Milisavljevic">{{Cite web|url=http://www.stsci.edu/cgi-bin/get-proposal-info?id=13505&observatory=HST|title = 13505 Program Information}}</ref> |
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NASA's press release about SN 2013ek said: |
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<blockquote>"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."<ref name="NASA_2013ek">{{citation|url=http://www.nasa.gov/content/goddard/stellar-explosions-in-ngc-6984/#.UoOpbJTXiBM|title=Hubble Catches Stellar Explosions in NGC 6984 | |
<blockquote>"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."<ref name="NASA_2013ek">{{citation|url=http://www.nasa.gov/content/goddard/stellar-explosions-in-ngc-6984/#.UoOpbJTXiBM|title=Hubble Catches Stellar Explosions in NGC 6984 | |
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archive-url=https://web.archive.org/web/20131121123254/http://www.nasa.gov/content/goddard/stellar-explosions-in-ngc-6984/#.UyVUsa2KAy8|archive-date=21 November 2013|publisher=[[NASA]]|date=13 November 2013}}</ref></blockquote> |
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== Gallery == |
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{{Gallery|width=200 |
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|File:NGC6984 - HST - Potw2144a.jpg|The galaxy NGC 6984, an elegant spiral galaxy in the constellation Indus roughly 200 million light-years away from Earth.}} |
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==References== |
==References== |
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{{reflist}} |
{{reflist}} |
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==External links== |
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* {{commons category-inline}} |
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{{Catalogs | NGC = 6984}} |
{{Catalogs | NGC = 6984}} |
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{{ |
{{Ngc70}} |
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{{Indus (constellation)}} |
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{{DEFAULTSORT:NGC 6984}} |
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[[Category: |
[[Category:Barred spiral galaxies]] |
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[[Category:Indus (constellation)]] |
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[[Category:NGC objects|6984]] |
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[[Category:Principal Galaxies Catalogue objects|065798]] |
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[[Category:IRAS catalogue objects|20543-5203]] |
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[[Category:Astronomical objects discovered in 1834]] |
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[[Category:Discoveries by John Herschel]] |
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{{galaxy-stub}} |
{{Spiral-galaxy-stub}} |
Latest revision as of 08:18, 12 October 2024
NGC 6984 | |
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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).[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
[edit]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
[edit]References
[edit]- ^ a b c d e f g "Search Results for NGC 6984". Astronomical Database. SIMBAD. Retrieved 5 November 2013.
- ^ "Stellar explosions in NGC 6984". ESA/Hubble Picture of the Week. Retrieved 5 November 2013.
- ^ a b c d e f "NGC 6984 - Spiral Galaxy in Indus". thesky.com. The Sky LIVE. Retrieved 12 Sep 2024.
- ^ "NGC 6984". simbad.u-strasbg.fr. Retrieved 12 Sep 2024.
- ^ Seligman, Courtney. "NGC 6984". Celestial Atlas. Retrieved 22 August 2024.
- ^ "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.
- ^ "SN 2012im". Transient Name Server. IAU. Retrieved 22 August 2024.
- ^ "ATel #4300: PESSTO spectroscopic classification of optical transients".
- ^ "CBET 3607 : 20130728 : SUPERNOVAE 2012im AND 2013ek IN NGC 6984". Central Bureau for Astronomical Telegrams (CBET). Retrieved 12 Sep 2024.
- ^ "ATel #5225: A new SN suspect at the position of SNhunt142 discovered 1 year ago".
- ^ "SN 2013ek". Transient Name Server. IAU. Retrieved 22 August 2024.
- ^ "ATel #5227: Spectroscopic classification for PSN J20575390-5152245 with FLOYDS at Faulkes Telescope South".
- ^ "13505 Program Information".
- ^ Hubble Catches Stellar Explosions in NGC 6984, NASA, 13 November 2013, archived from the original on 21 November 2013
External links
[edit]- Media related to NGC 6984 at Wikimedia Commons