IM Nor: Recurrent Nova
W. Liller discovered an eruption of the recurrent nova IM Nor on photographs
taken between Jan. 10.3432 and Jan 10.3595. The object had already been
bright as seen in photos taken on Jan. 3.3479 and Jan. 3.3493, and nothing
was visible at the position of the star on Oct. 13 down to magnitude 11.5.
IM Nor was originally discovered by I.E. Woods at 9th magnitude on a
blue-sensitive plate taken on July 7, 1920. No other outbursts were found
(vsnet-campaign-npva
689, 695,
700,
vsnet-campaign-news
122). The proposed identification of IM Nor with 2U 1536-52 (as referred
in IAUC 7789) has proven to be false. 2U 1536-52 is an high-mass X-ray
binary QV Nor (vsnet-campaign-nova
717). A low-dispersion objective prism spectrum, taken Jan. 12.351
UT by W. Liller, showed H-alpha to be very strong and relatively narrow
with FWHM = 950 km/sec +/-50 (vsnet-campaign-nova
707, 708).
T. Kato suggested its outburst amplitude of 9mag (vsnet-campaign-nova
716, 718,
719,
720,
721).
B. Liller reported that the object was V=7.84 and brightening on January
14 (vsnet-campaign-nova
728). Visual observations also confirmed this tendency (vsnet-campaign-nova
735). Subsequently, B. Liller reported further brighter magnitude
of V=7.66 on January 16 (vsnet-campaign-nova
737). In late January 16, the object is reported to suddenly faded
to 8.7mag (vsnet-campaign-nova
738). The similar fading was confirmed on January 17 by G. J. Garradd
(vsnet-campaign-nova
744, 746,
750),
and then the object started gradual fading (vsnet-campaign-nova
755). The object entered a plateau phase in September (vsnet-campaign-nova
974).
Other articles:
vsnet-campaign-nova
710, 712,
715,
725,
742,
733,
752,
760,
761,
763,
779,
784,
788,
791,
804,
807,
809,
810,
812,
815,
816,
820,
821,
822,
823,
829,
831,
835,
839,
849,
861,
865,
873,
886,
896,
924,
933
Links:
Some useful comparison stars, see [vsnet-campaign-nova
699]
Sequence, see [vsnet-campaign-nova
702, 726]
IM Nor CCD image taken by B. Monard:
ftp://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/Novae/IM_Nor/monard.gif
[vsnet-campaign-nova
734]
Preprint by T. Kato et al.:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-preprint/msg00078.html
VSNET special page for this object:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Novae/imnor.html