Note: this is an archived version which has been superseded.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.

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

References:

• Bell et al. 1975, Nat, 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
• Dickel et al. 1982, ApJ, 257, 145. Comparison of X-ray, Radio and HRI. ADS
• Kamper & van den Bergh 1983, in IAU101, p55. Optical expansion.
• Markert et al. 1983, ApJ, 268, 778. X-ray asymmetry. 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
• Tsunemi et al. 1986, ApJ, 306, 248. X-ray spectrum. 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
• Jansen et al. 1988, ApJ, 331, 949. EXOSAT observations. 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
• Greidanus & Strom 1991, A&A, 249, 521. 20micron observations of part of shell. 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. NH3 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

Last updated: 20 AUG 1996