Discovery of two probable novae in NGC 2403

ATel #1638; K. Hornoch (Astronomical Institute, Academy of Sciences, Ondrejov, Czech Republic)
on 30 Jul 2008; 17:16 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Marek Wolf (wolf@cesnet.cz)

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I report the discovery of two probable novae in NGC 2403. The new objects were found on archival narrowband [H_alpha] images taken with the 2.54-m Isaac Newton Telescope (INT) at La Palma, and obtained from the ING Archive. The first object was discovered on image taken on 2002 Dec. 30.124 UT and is located at R.A. = 7h37m38s.36, Decl. +65o36'29".8 (equinox 2000.0), which is 295".8 east and 20".2 north of the center of NGC 2403. The second object was found on image taken on 2005 Jan. 14.949 UT and is located at R.A. = 7h36m53s.98, Decl. +65o34'54".7 (equinox 2000.0), which is 20".9 east and 74".9 south of the center of NGC 2403. Both novae are visible on single images used for co-added images.

Available magnitudes ([H_alpha], unless otherwise noted) for the first object: 2001 Feb. 21.917, [22.6 (observer unknown, INT); 2002 Nov. 6.618, [24.7 (R-band, G. Kosugi et al., Subaru telescope at Mauna Kea); 9.166, [23.0 (V-band, P. Royer, 4.2-m WHT at La Palma); Dec. 30.124, 18.28 (M. Watson, INT); 30.135, 20.86 (Sloan r', Watson, INT); 2003 Jan. 4, 21.4: (estimated R-band magnitude from LRGB image taken by Ch. Olson and J. Lapre with the 0.41-m telescope at the Kitt Peak visitor center, AZ); 2004 Jan. 30.964, [21.9 (observer unknown, INT); Feb. 12.920, [21.5 (A. Herrero, INT); 2005 Jan. 8.312, [24.6 (V-band, N. Arimoto et al., Subaru); 8.370, [24.1 (I-band, Arimoto et al., Subaru); 14.949, [21.3 (A. Cardwell, INT); 15.036, [22.5 (B-band, Cardwell, INT); Mar. 20.884, [22.0 (R-band, P. James, INT); 20.892, [21.8 (James, INT); 2006 Mar. 11.909, [22.3 (J. E. Beckman, INT); 13.953, [22.1 (Beckman, INT); Mar. 14.947, [21.6 (Beckman, INT).

Available magnitudes for the second object (as above): 2001 Feb. 21.917, [22.6 (observer unknown, INT); 2002 Nov. 6.618, [24.5 (R-band, Kosugi et al., Subaru); 9.166, [23.0 (V-band, Royer, WHT); Dec. 30.124, [22.1 (Watson, INT); 30.135, [23.2 (Sloan r', Watson, INT); 2004 Jan. 30.964, [21.9 (observer unknown, INT); Feb. 12.920, [21.5 (Herrero, INT); Aug. 17.184, [23.3 (A. V. Filippenko, HST-ACS); 2005 Jan. 8.312, [24.0 (V-band, Arimoto et al., Subaru); 8.370, [23.7 (I-band, Arimoto et al., Subaru); 14.949, 19.3 (Cardwell, INT); 15.036, [22.5 (B-band, Cardwell, INT); Mar. 20.884, [22.0 (R-band, James, INT); 20.892, 19.7 (James, INT); 2006 Mar. 11.909, 21.9 (Beckman, INT); 13.953, 21.8: (Beckman, INT); Mar. 14.947, [21.6 (Beckman, INT).

Note that [H_alpha] limiting magnitude from the HST-ACS F658N filtered image is in STMAG system. HST images were obtained from the ESO HST archive; the 4.2-m WHT images from the ING archive, and SUBARU images from the SMOKA archive.