GK Per: Rare Outburst in 2002
Since mid-January, 2002, some observers had reported a slow brightening of
GK Per (vsnet-campaign-ip
84, vsnet-campaign-dn
2062). The gradual brightening continued also during February (vsnet-campaign-gkper
2), and based on the past recurrence times of outbursts of GK Per,
a new outburst was predicted (vsnet-campaign-gkper
1, 3,
4).
On March 2, the expected outburst was reported to start (vsnet-campaign-gkper
28, 29,
30).
The rising rate was first relatively large, but soon became more gradual
(vsnet-campaign-gkper
31, 33,
34,
35,
36).
The Kyoto team performed time-series photometry on March 8 and 9. The
resultant light curve showed strong modulations with multiple frequencies
of 518s and 4510s (vsnet-campaign-gkper
49). The strong modulations were still evident in the data on March
11. M. Uemura reported that there was no phase shift of the long-term
QPO, which indicates its coherence time was, at least, 4 days (vsnet-campaign-gkper
55).
The brightening rate again increased at a rate of 0.05mag/d since March 16,
while it was relatively calm before March 15. The long-term (P~0.0525d)
and short-term (0.005-0.007d) modulations were continuously detected (vsnet-campaign-gkper
60, 62,
69).
M. Uemura reported that the 0.006-0.008 d periodicity appeared to weaken
since March 25 while the spin periodicity (~0.004 d) and 0.0525-d one
are still evident (vsnet-campaign-gkper
72, 74).
The 0.0525-d modulations seemed to have highly variable profiles in
each cycle, but have high coherent period (vsnet-campaign-gkper
74, 75).
The brightening at 0.05mag/d continued until April 5 when M. Uemura detected
a start of fading (vsnet-campaign-gkper
77, 78,
80,
81,
82).
The power spectrum in high frequencies was dominated by the spin periodicity.
A possible longer periodicity was reported on April 1 and 2 by M. Uemura
(vsnet-campaign-gkper
79, 82).
The fading became rapider from April 17. The long-term and spin modulations
were still evident during this final outburst phase (vsnet-campaign-gkper
86).
Other articles:
vsnet-campaign-gkper
5, 6,
7,
8,
9,
10,
11,
12,
13,
14,
15,
16,
17,
18,
19,
20,
21,
22,
23,
24,
25,
26,
27,
32,
41,
42,
43,
44,
46,
47,
48,
50,
51,
56,
57,
58,
59,
61,
63,
64,
65,
66,
67,
68,
70,
71,
73,
76,
83,
84,
85,
87,
vsnet-campaign
1295
Links:
Comparison stars for GK Per, see [vsnet-campaign-gkper
37, 40]
Sequence presented by B. Skiff, see the links at:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Novae/gkper.html
[vsnet-campaign-gkper
38]
New charts by AAVSO:
http://www.aavso.org/charts/PER/GK_PER/
Special edition of CCD Views (AAVSO):
http://www.aavso.org/ccdviews/ccdviewsspecial-gkper.shtml
[vsnet-campaign-gkper
45]
Information about comparison stars, see [vsnet-campaign-gkper
52, 53,
54]
Time-series photometry provided by L. Kral, see [vsnet-campaign-data
92]
Time-series photometry by T. Havlik, see [vsnet-campaign-data
93]
Time-series photometry by M. Kolasa, see [vsnet-campaign-data
94]
Paper by Nogami et al.:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-preprint/msg00087.html