WR 104

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WR 104
Observation data
Epoch 2000      Equinox 2000
Constellation Sagittarius
Right ascension 18h 02m 04.07s
Declination −23° 37′ 41.2″
Apparent magnitude (V) 13.54
Spectral type WC9d/B0.5V[1]
Distance 2,300[1] pc
Absolute magnitude (MV) -5.4 (combined)[2]
Radius ~8[3] R
Luminosity ~150,000[3] L
Temperature 40,000[3] K
Other designations
V5097 Sgr, IRAS 17590-2337, MR 80, UCAC2 22296214, CSI-23-17590, IRC-20417, MSX6C G006.4432-00.4858, Ve 2-45, Had V82, JP11 5559, RAFGL 2048
Database references

Coordinates: Sky map 18h 02m 04.07s, −23° 37′ 41.2″

WR 104 is a Wolf–Rayet star discovered in 1998, located 8,000 light years from Earth. It is a binary star with an OB companion. The stars have an orbital period of 220 days and the interaction between their stellar winds produce a spiral "pinwheel" outflow pattern over 200 astronomical units long.[4] The spiral is composed of dust that would normally be prevented from forming by WR 104's intense radiation were it not for the star's companion. The region where the stellar wind from the two massive stars interacts compresses the material enough for the dust to form, and the rotation of the system causes the spiral-shaped pattern.[5]

Some optical measurements indicate that WR 104's rotational axis is aligned within 16° of Earth.[4] This could have potential implications to the effects of WR 104's eventual supernova, since these explosions often produce jets from their rotational poles. It is possible that WR 104 may even produce a gamma-ray burst, though it is not possible to predict with certainty at this time.[5] Newer spectroscopic data suggest that WR 104's rotational axis is more likely angled 30–40° from Earth.[6][7]


  1. ^ a b Van Der Hucht, K. A. (2001). "The VIIth catalogue of galactic Wolf–Rayet stars". New Astronomy Reviews 45 (3): 135. doi:10.1016/S1387-6473(00)00112-3.  edit
  2. ^ Williams, P. M.; Van Der Hucht, K. A. (2000). "Spectroscopy of WC9 Wolf-Rayet stars: A search for companions". Monthly Notices of the Royal Astronomical Society 314: 23. doi:10.1046/j.1365-8711.2000.03332.x.  edit
  3. ^ a b c Sander, A.; Hamann, W. -R.; Todt, H. (2012). "The Galactic WC stars". Astronomy & Astrophysics 540: A144. arXiv:1201.6354. Bibcode:2012A&A...540A.144S. doi:10.1051/0004-6361/201117830.  edit
  4. ^ a b Tuthill, P. G.; Monnier, J. D.; Lawrance, N.; Danchi, W. C.; Owocki, S. P.; Gayley, K. G. (2008). "The Prototype Colliding‐Wind Pinwheel WR 104". The Astrophysical Journal 675: 698. doi:10.1086/527286.  edit
  5. ^ a b Tuthill, P. G.; Monnier, J. D.; Danchi, W. C. (1999). "A dusty pinwheel nebula around the massive star WR104". Nature 398 (6727): 487. Bibcode:1999Natur.398..487T. doi:10.1038/19033.  edit
  6. ^ Discovery News August 4, 2009 Retrieved May 18, 2010
  7. ^ Universe Today January 7, 2009 Retrieved September 3, 2010

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