[vsnet-campaign-nova 1101] Prediscovery positive observation of the possible nova in M110

[Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>]

Prediscovery positive observation of the possible nova in M110

    We report the following prediscovery positive observation of the
possible nova in NGC 205.  The (presumable) nova was rapidly rising at the
time of Itagaki's discovery, and showed a very rapid decline thereafter
(the post-discovery light curve even resembles that of V1500 Cyg).
Judging from Itagaki's observation, the nova was then rising at a rate
of 0.3 mag/hr.  The present observation is far brighter than a smooth
extrapolation of this rising rate, suggesting that the nova was in
"premaximum halt" phase.  The premaximum halts in very fast novae usually
last several hours.  The bright positive detection 1 d before the final
rise is thus already surprizing!  This positive prediscovery detection
seems to be extremely valuable in terms of nova physics.

    Attached is an article submitted to IAUC.

Regards,
Taichi Kato
---

POSSIBLE NOVA IN NGC 205
     H. Yamaoka, Kyushu University, and T. Kato, Kyoto University,
report that a prediscovery unfiltered CCD image taken by Y. Mashitani
(Tenkawa, Nara, Japan, via N. Fukuhara, Hyogo, Japan) on Oct. 4.760 UT
with a 0.20-m Baker-Schmidt telescope shows the possible nova at mag
about 17.0.  It suggest that the object might be on a premaximum halt
phase.  Such a long halt is exceptional for a very fast nova.

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp