Note: this is an archived version which has been superseded. The current SNR catalogue is at http://www.mrao.cam.ac.uk/surveys/snrs/

G111.7-2.1 Cassiopeia A, 3C461

• Right Ascension: 23 21 10
• Declination: +58 32
• Size (/arcmin): 5
• Type: S
• Flux density at 1 GHz (/Jy): 2720
• Spectral Index: 0.77

Notes: Presumably the remnant of a late 17th century SN.

Radio: Bright shell with compact knots and extended plateau of emission.

Optical: Fast knots and quasi-stationary flocculli, with many filaments at large radii.

X-ray: Incomplete shell, with hard spectral component.

Distance: Optical expansion, plus proper motions indicate 2.8 kpc.

References:

• Bell et al. 1975, Natur, 257, 463. 5km at 5 GHz (2"×2".3). ADS
• Green et al. 1975, A&A, 44, 187. Effelsberg 100-m at 15.0 GHz (58": S=419.1±1.7). ADS
• Fabian et al. 1980, MNRAS, 193, 175. HRI observations. ADS
• Tuffs 1986, MNRAS, 219, 13. Proper motions from 5km maps at 5 GHz (2"×2".3) between 1974 and 1978. ADS
• Mezger et al. 1986, A&A, 167, 145. 247-GHz map (70"). ADS
• Fesen et al. 1987, ApJ, 313, 378. Optical, of fast moving flocculli. ADS
• Fesen et al. 1988, ApJ, 329, L89. Optical, flocculli, and `flare'. ADS
• Woan & Duffett-Smith 1990, MNRAS, 243, 87. Structure at 81.5 MHz. ADS
• Fesen 1990, AJ, 99, 1904. [NeIII] optical imagery. ADS
• Rees 1990, MNRAS, 243, 637. Flux density decrease at 38 MHz. ADS
• Anderson et al. 1991, ApJ, 373, 146. VLA at 1.4 and 5 GHz (1".3) for spectral variations. ADS
• Hook et al. 1992, A&A, 255, 285. Flux density decrease at 81.5 MHz. ADS
• Wilson et al. 1993, A&A, 280, 221. Molecular emission towards remnant. ADS
• Holt et al. 1994, PASJ, 46, L151. X-ray spectral mapping. ADS
• Woan & Duffett-Smith 1993, MNRAS, 260, 693. Deep pulsar search. ADS
• Guame et al. 1994, ApJ, 425, 127. NH<sub>3</sub> absorption and CO observations. ADS
• Iyudin et al. 1994, A&A, 284, L1. gamma-ray line observations. ADS
• Reed et al. 1995, ApJ, 440, 706. Optical spectra, for 3-d structure. ADS
• Anderson et al. 1995, ApJ, 441, 300. VLA at 1.4 GHz and 4.8 GHz (both 1".3), for polarization studies. ADS
• Anderson & Rudnick 1995, ApJ, 441, 307. VLA at 1.4 GHz and 4.8 GHz, for proper motion studies. ADS
• The et al. 1995, ApJ, 444, 244. gamma-ray observations. ADS
• Predehl & Schmitt 1995, A&A, 293, 889. ROSAT of dust scattered halo. ADS
• Liszt & Lucas 1995, A&A, 294, 811. NRAO 12-m observations of molecular emission and absorption. ADS
• Lawrence et al. 1995, AJ, 109, 2635. Optical imaging spectroscopy. ADS
• Kassim et al. 1995, ApJ, 455, L59. VLA at 74 (25") and 332 MHz (6"), including spectral index comparisons. ADS
• Anderson & Rudnick 1996, ApJ, 456, 234. VLA for spectral index comparisons. ADS
• Agafanov 1996, A&A, 306, 578. Flux density decrease at 102 MHz. ADS
• Biggs & Lyne 1996, MNRAS, 282, 691. Pulsar search. ADS
• Vink et al. 1996, A&A, 307, L41. ASCA spectrum. ADS
• Lagage et al. 1996, A&A, 315, L273. ISO observations. ADS
• Keohane et al. 1996, ApJ, 466, 309. Radio and X-ray comparison. ADS
• Hurford & Fesen 1996, ApJ, 469, 246. Optical spectroscopy and reddening studies. ADS
• Fesen & Gunderson 1996, ApJ, 470, 967. Optical observations of NE `jet'. ADS
• Allen et al. 1997, ApJ, 487, L97. X-ray spectroscopy. ADS
• Schwarz et al. 1997, A&AS, 123, 43. WST at 1.4 GHz (30") for HI absorption. ADS
• Reynoso et al. 1997, A&A, 317, 203. VLA at 1.4 GHz (11"×14") for HI absorption. ADS
• Favata et al. 1997, A&A, 324, L49. X-ray spectroscopy. ADS
• Dupraz et al. 1997, A&A, 324, 683. gamma-ray line detection. ADS
• Lorimer et al. 1998, A&A, 331, 1002. Pulsar search. ADS

Last updated: 17 AUG 1998