NGC 4993

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Galaxy
NGC 4993
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NGC 4993 with gamma-ray flash GRB 170817A
NGC 4993 with gamma-ray flash GRB 170817A
AladinLite
Constellation Water snake
Position
equinox :  J2000.0 , epoch : J2000.0
Right ascension 13 h 09 m 47.7 s
declination -23 ° 23 ′ 02 ″
Appearance
Morphological type (R ') SAB (rs) 0-  
Brightness  (visual) 12.4 mag
Brightness  (B-band) 13.4 mag
Angular expansion 1.3 ′ × 1.1 ′
Position angle 168 °
Surface brightness 12.9 mag / arcmin²
Physical data
Affiliation LGG 332  
Redshift 0.009727 +/- 0.000050  
Radial velocity 2916 +/- 15 km / s  
Stroke distance
v rad  / H 0 		(124 ± 9)  ·  10 6  ly
(38.1 ± 2.7)  Mpc 
history
discovery Wilhelm Herschel
John Herschel
Discovery date March 26, 1789
March 25, 1836
Catalog names
NGC  4993, 4994 • PGC  45657 • ESO  508-G018 • MCG  -04-31-039 • 2MASX  J13094770-2323017 • SGC  130705-2307.1 • GC  3428, 3429 • H  III 766 • h  3471 • AM 1307-230 • LDCE 0955 NED007

NGC 4993 = NGC 4994 is an elliptical galaxy in the constellation of the Water Snake . Estimates of the distance using various methods give results in the range of around 130 million light years . On August 17, 2017, a gravitational wave burst with a simultaneous gamma ray burst was discovered in this galaxy .

Observations

Synopsis of the physical signals

On August 17, 2017, a gravitational wave signal ( GW170817 ) and a gamma-ray burst ( GRB170817A ) were observed in coincidence, the origin of which was in this galaxy. The observation can be explained by the collision of two neutron stars ( kilonova ), which generally suggests such events as (a) cause of GRBs.

Discovery story

The galaxy was discovered twice; first on March 26, 1789 by Wilhelm Herschel with an 18.7-inch reflecting telescope, who described it as “vF, vS” (observation listed as NGC 4993 ); then on March 25, 1836 by John Herschel , who "pF, R, slbM, 35 arcseconds. Among stars ”(listed as NGC 4994 ).

Web links

Individual evidence

  1. ↑ a b c d NASA / IPAC EXTRAGALACTIC DATABASE
  2. ↑ a b c d e f SEDS : NGC 4993
  3. ↑ Nadia Drake: Strange Stars Caught Wrinkling Spacetime? Get the facts. . In: National Geographic . August 25, 2017. Retrieved August 27, 2017.
  4. ↑ B. P. et al Abbott: GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral . In: Physical Review Letters . 119, No. 16, October 16, 2017. doi : 10.1103 / PhysRevLett.119.161101 .
  5. ^ NASA Missions Catch First Light from a Gravitational-Wave Event . In: NASA , October 16, 2017. 
  6. ^ Adrian Cho: Merging neutron stars generate gravitational waves and a celestial light show . In: Science , October 16, 2017. 
  7. ↑ Lisa M. Krieger: A Bright Light Seen Across The Universe, Proving Einstein Right - Violent collisions source of our gold, silver . In: The Mercury News , October 16, 2017. 
  8. ^ Andreas von Kienlin: GCN Circular; Number: 21520; GRB 170817A: Fermi GBM detection; 2017/08/17 20:00:07 GMT . In: Max Planck Institute for Extraterrestrial Physics . August 17, 2017. Retrieved August 28, 2017.
  9. ↑ Davide Castelvecchi: Rumors swell over new kind of gravitational-wave sighting , Nature News . August 25, 2017. Accessed August 27, 2017. 
  10. ↑ Joshua Sokol: What Happens When Two Neutron Stars Collide? . In: Wired . August 25, 2017. Retrieved August 28, 2017.
  11. ↑ Dennis Overbye: LIGO Detects Fierce Collision of Neutron Stars for the First Time (en-US) . In: The New York Times , October 16, 2017. 
  12. ^ Matthew Wright: Neutron star merger directly observed for the first time , on: EurekAlert! (University of Maryland)
  13. ↑ Marlene Weiß: Astronomers observe the origin of gravitational waves for the first time , on: Süddeutsche.de from October 16, 2017
  14. ↑ dpa: Gravitational waves from colliding neutron stars recorded on: Hessische Niedersächsische Allgemeine (HNA) from October 16, 2017, as well as: Gravitational waves from colliding neutron stars recorded on: Süddeutsche.de from October 16, 2017
  15. ↑ Robert Gast: Neutron star crash causes space-time to tremble , on: Spektrum.de from October 16, 2017
  16. ↑ First gravitational waves from neutron star collision ( Memento of the original from October 18, 2017 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , to: scinexx @1@ 2Template: Webachiv / IABot / www.scinexx.de
  17. ↑ Auke Slotegraaf: NGC 4993. Deep Sky Observer's Companion, accessed on February 24, 2015 (English).
  18. ↑ Auke Slotegraaf: NGC 4994. Deep Sky Observer's Companion, accessed on February 24, 2015 (English).
  19. ↑ Seligman