CU Vel: Superoutburst in December
As detected by R. Stubbings on December 10, the SU UMa-type dwarf nova CU
Vel experienced an outburst (vsnet-campaign-dn
3110, 3112).
In the light curve taken by G. Bolt on December 11, clear superhumps were
detected. In addition to superhumps, there was strong evidence of super-QPOs
with relatively large amplitudes. T. Kato commented that the similarity
of the pattern of super-QPOs and early-stage superhumps with that of EF Peg
may suggest these features may be closely associated with long-period SU
UMa-type dwarf novae with relatively rare superoutbursts (vsnet-campaign-dn
3126). On December 14, the superhumps had fully grown with an amplitude
of 0.25 mag. Prominent super-QPO-type signal on Dec. 11 looks like to have
disappeared.
A preliminary analysis of the data by T. Kato yielded a superhump period
of 0.0809-0.0811 d (vsnet-campaign-dn
3129, 3136).
The superhump period was dramatically changed during the early superoutburst
phase. After this phase, the object showed a firm superhump period of 0.08085(3)
d (vsnet-campaign-dn
3137). On December 16 and 17, the light curves showed broader superhumps
with slightly longer superhump period. The period increase of superhumps
is usually a characteristic of short Psh systems related to WZ Sge-type stars,
and is quite unusual for a long Psh system (vsnet-campaign-dn
3143, 3153).
T. Kato reported on December 20 that the superhump period may then turned
to decrease (vsnet-campaign-dn
3158, 3164,
3167).
The amplitude of superhumps started decreasing, and the signature of secondary
superhumps became stronger (vsnet-campaign-dn
3167, 3177).
The superoutburst has entered a rapid fading phase, as indicated by the observation
by R. Stubbings on December 24 (vsnet-campaign-dn
3183, 3186).
After the rapid fading, the light curve on December 26 by P. Nelson showed
double-wave modulations, which were likely related to late superhumps (vsnet-campaign-dn
3201).
Other articles:
vsnet-campaign-dn
3130, 3134,
3139,
3145,
3149,
3155,
3172
Links:
Outburst image taken by P. Nelson:
/vsnet/ftpfile/DNe/CU_Vel/cunelson.gif
Outburst image taken by B. Heathcote:
/vsnet/ftpfile/DNe/CU_Vel/heathcote.jpg
[vsnet-campaign-dn
3135]
VSNET special page for this object:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/cuvel0212.html
[vsnet-campaign-dn
3138]
Combined light curve on Dec. 17:
/vsnet/ftpfile/DNe/CU_Vel/sh17.gif
[vsnet-campaign-dn
3147]