SN 2014J in M82: Non-detections of a possible progenitor outburst in archival Tautenburg observatory data
ATel #5933; M. Henze (ESA/ESAC), H. Meusinger (TLS Tautenburg)
on 28 Feb 2014; 14:33 UT
Credential Certification: Martin Henze (firstname.lastname@example.org)
Subjects: Optical, Nova, Supernovae
Following ATel #5824, we report the non-detections of a possible nova progenitor to the type Ia supernova (SN Ia) 2014J in M82 (Fossey et al., CBET 3792) in archival optical images obtained between 1961 and 2013. The data set consists of 173 individual observations taken with the Tautenburg observatory 1.34 m Schmidt camera. Co-adding all exposures obtained through the same filter within five-day intervals yielded 38 epochs with a median epoch difference of 0.8 yr. Of these, 29 epochs are covered by 60 digitised photographic plates taken until 1998 through different filters (8 U, 29 B, 18 V, 5 R) and another 9 epochs are covered by 113 CCD frames (filters: B, V, R, I, Hα, SII, OIII). All epochs are listed below. The limiting magnitudes of the co-added exposures in the outer field of M82 are estimated to be typically >19...20 mag for the photographic plates and >21 mag for the CCD images. Simple modelling shows that the limit is reduced by about 0.5 mag at the position of SN 2014J due to the bright local background. We visually inspected both each single image of M82 and the co-added images. We did not find any clear-cut evidence for a star-like object at the position of SN 2014J.
According to the single-degenerate scenario (Whelan & Iben 1973, ApJ 186, 1007), possible SN Ia progenitors are accreting CO white dwarfs (WDs) with close, evolved binary companions. For a specific range of accretion rates such a binary system is expected to produce classical or recurrent nova outbursts (Nomoto 1982, ApJ, 253, 798). In particular, recurrent novae, which have shown multiple nova outburst and likely contain a WD with a mass close to the Chandrasekhar limit, are discussed as potential SN Ia progenitors (e.g. Kato & Hachisu 2012, BASI, 40, 393). Archival Hubble Space Telescope data did not rule out a binary system with the characteristics of known Galactic or extragalactic novae (ATel #5824).
A large sample of extragalactic novae in our neighbour galaxy M31 shows that their outbursts can reach peak absolute magnitudes of up to V = -10 mag (see Shafter et al. 2009, ApJ, 690, 1148; as well as Pietsch et al. 2007, A&A, 465, 375 and the corresponding online catalogue here). Assuming a distance modulus for M82 of 27.72 mag (Karachentsev & Kashibadze, 2006, Ap, 49, 3) and reasonable extinction values (cf. ATel #5849), this means that bright novae in outburst are within the reach of our archival observations.
Of course, these non-detections do not rule out a nova progenitor for SN 2014J. Although the Tautenburg archive provides an outstanding combination of long-term coverage over half a century and limiting magnitude, the overall detection probability is still low. On average, bright novae fade fast: by several magnitudes within days to weeks (della Valle & Livio, 1995, ApJ, 452, 704). We encourage the inspection of other archival data that might realistically detect a nova outburst in M82.
Observation epochs and corresponding filters
Photographic plates: 1961-04-09 (B), 1967-02-06 (B), 1967-02-07 (V), 1967-02-13 (B), 1967-02-14 (V), 1967-02-16 (R), 1968-03-02 (B,U), 1969-01-17 (U,B,V), 1969-02-16 (V), 1970-11-29 (B), 1976-02-23 (U,V), 1976-02-29 (B), 1978-03-11 (U), 1983-04-17 (U), 1986-06-10 (R), 1989-12-02 (B), 1990-03-16 (B), 1991-12-12 (B), 1992-03-04 (B), 1993-05-16 (B), 1993-06-15 (B), 1997-02-02 (B), 1997-04-09 (B), 1997-05-07 (V), 1998-01-31 (V)
CCD images: 2005-04-02 (B,V,R), 2005-06-29 (B,V,Hα), 2007-04-10 (B,V), 2009-09-23 (V,R,I), 2011-03-04 (B,V,Hα), 2011-12-29 (OIII), 2012-01-18 (Hα, OIII), 2012-04-18 (B,R,OIII), 2013-04-07 (SII)