1RXS J232953.9+062814 : New SU UMa star with a ultrashort period
P. Schmeer reported an outburst of this recently discovered dwarf
nova at 12.5mag on November 3
(vsnet-campaign 1205).
The Kyoto team performed time-series observation on November 4
(vsnet-campaign 1206), and detected
strong humps with a very short period of 0.043 day
(vsnet-campaign 1208).
As also confimed by T. Vanmunster on Novemver 5/6, this object turned
out to be a new SU UMa star below the period minimum
(vsnet-campaign 1211,
1212,
1213).
According to Jingyao et al (1998), The outburst spectrum resembles
that of an A-star. The quiescent spectrum was dominated by Balmer and
He I emission lines, indicating that the object is not hydrogen-poor
(vsnet-campaign-dn 1844).
The Gunma team performed spectroscopy and reported a spectra with weak
absorption lines of H-beta, H-gamma and H-delta, and the H-alpha
emission
(vsnet-campaign-dn 1861).
B. Skiff reported a proper motion of this object to be 0"".049/yer
using USNO-A2.0 and GSC-2.2 catalogues
(vsnet-campaign-dn 1851).
H. Yamaoka also reported to be 0".05 - 0".06 /yr using the Kyoto
images
(vsnet-campaign-dn 1857).
The superhump period was calculated to be 0.046330(10) d
(vsnet-campaign-dn 1854).
T. Kato reported a period increase of superhumps. The mean period
derivative is dot{P}/P = 6x10^(-5)
(vsnet-campaign-dn 1859).
The amplitude of humps became smaller with time, and on November 7,
the object rapidly faded
(vsnet-campaign 1219).
The fading rate became gradual on November 9
(vsnet-campaign-dn 1864).
On late November 9, the object experienced a rebrightening reaching
13.0mag
(vsnet-campaign 1220).
During this rebrightening, T. Vanmunster detected superhumps as in
the plateau phase
(vsnet-campaign 1223).
It has faded with the duration of about 1 day
(vsnet-campaign-dn 1876).
T. Kato commented that the persistence of superhumps is similar to
ER UMa stars
(vsnet-campaign-dn 1879).
The D. Starkey's data on the fading phase show a slightly shorter
periodicity of 0.04608(4) d, indicating a possible orbital modulations
(vsnet-campaign-dn 1880).
It showed superhumps and sometimes double humps after the
rebrightening
(vsnet-campaign-dn 1885).
Using the data on November 13 and 14, the period analysis yielded
0.04591(8) d, which is 0.8% shorter than the superhump period. The
emergence of a significantly different period is highly suggestive of
the (co-)existence of orbital modulations
(vsnet-campaign-dn 1888).
The superhump signal became weak on November 16
(vsnet-campaign-dn 1899).
The light curve was then dominated by double-wave humps, with
occasional brightenings (time scale ~1-2 hr), during which humps tend
to become rather unclear
(vsnet-campaign-dn 1921).
The later light curve on November 19 - 21 showed two periodicity
of 0.044590(16) d and 0.045935(67) d. The former probably corresponds
to orbital periods, and the latter is superhumps
(vsnet-campaign-dn 1935).
Both observations by the Kyoto team and T. Krajci detected
a small rebrightening started on December 2. The rising rate
was relatively slow, and the object became 0.15mag brighter on
the monotonous gradual decline trend on December 2 - 3. After
this peak, its fading rate returned to the monotonous gradual
trend before the rebrightening
(vsnet-campaign 1237).
Superhump light curve by the Kyoto team
Image during the outburst by the Kyoto team
Other related articles:
vsnet-campaign 1209,
1214,
1215,
1216,
1218,
1220,
1224,
1225,
vsnet-campaign-dn 1853,
1875,
1843,
1845,
1847,
1850,
1852,
1858,
1860,
1863,
1877,
1878,
1884,
1885,
1892,
1893,
1903
Links:
VSNET web page:
http://www.kusastro.kyoto-u.ac.jp/vsnet/DNe/J2329.html