Outburst of GK Per


(vsnet-alert 342)

According to the report ( vsnet-obs 2211) of J. Mc Kenna (AAVSO), the old nova GK Per may be undergoing one of its minor outbursts since its last one in 1992 July. This old nova (and also known as an intermediate polar) recently shows these presumably dwarf nova-type outbursts every ~3 years. The present outburst (if confirmed) may provide an opportunity in probing this "excellent laboratory of magnetic accretion".

    1996 Feb. 26.054 UT  mv=12.4  J. Mc Kenna

Some selected litertures:
  * on short-term oscillations (QPOs, intermediate polar):
    J. Patterson 1991, PASP 103, 1149 (optical)
    M. Ishida et al. 1992, MNRAS 254, 647 (X-ray)

  * on minor brightenings:
    A. Bianchini et al. 1986, A&A 160, 367 (analysis of light curve)
    S. -W. Kim et al. 1992, ApJ 384, 269 (dwarf nova-type model)

We would like to be providing updated information of this phenomenon through the VSNET home page (http://www.kusastro.kyoto-u.ac.jp/vsnet) and anonymous ftp ( ftp://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/Novae/GK_Per).

Regards,
Taichi Kato (VSNET sub-manager)

P. Schmeer reports further observations.

Visual magnitude estimates by P. Schmeer, Bischmisheim, Germany:
 
GK PERSEI  (NA+UGSS)
Jan. 21.949 UT,  12.9 ; 30.890,  13.0:; 31.820,  13.0 ;
Feb.  1.850 UT,  13.0:;  5.812,  12.9 ; 23.828,  12.9 ; 25.819,  12.7
Sequence:   AAVSO
Instrument: 203-mm SCT
Fluctuation or start of a minor outburst?

These observations have been confirmed by visual observations (IAUC 6325) and by CCD photometry by D. Nogami (Ouda Station).

(vsnet-obs 2216)

TAUSU    960223.573  18.05  Oud
ORIV1159 960224.395  13.82  Oud
PERGK    960226.463  12.39  Oud

Ouda Station: 60-cm refl. + CCD + Johnson V filter

Regards,
Daisaku Nogami

AAVSO NEWS FLASH

AAVSO NEWS FLASH No. 2

AAVSO NEWS FLASH No. 4

AAVSO NEWS FLASH No. 9

V-band image on Mar. 10 (Ouda Station)

V-band image on Mar. 20 (Ouda Station)


Comparison stars (Skiff)

(vsnet 241, Brian Skiff)

Folks,

The AAVSO webpage alert notice 211 (1 August 1995) with regard to GK Persei included a chart that has a sequence dating from 1929. Surely this is one in need of a check via photoelectric photometry! There appears to be no modern published photometry (other than differential) for stars in the field. Everyone can rest easily, since it appears that both the zero-point and scale are basically correct, at least for the seven stars I measured, which span much of the range of magnitudes covered by the (f)-scale AAVSO chart. The bright star "99" (BD+43 0743) appears only on the (e)-scale chart.

The results below are from single observations except for the three faintest stars, which got two nights. N.B. the large uncertainty for the mag. 14 star, which is probably due to instrumental noise rather than variability in the star.

\Brian



AAVSO  Name             RA  (2000)  Dec         V      b-y    remarks
      GK Persei       3 31 12.0  +43 54 16   12.940   0.700    (1)

  91  HD 21588        3 30 51.5  +43 59 06    9.085   0.178    (2)

  99  BD+43 0743      3 31 55.9  +44 02 45    9.667   0.760    (3)

 108  GSC 2874-0934   3 31 47.7  +43 54 22   11.061   0.252

 123  GSC 2874-1053   3 30 47.7  +43 52 50   12.164   0.497

 126  GSC 2874-0734   3 30 53.4  +43 56 19   12.558   0.437
                                               .009    .006
 132  GSC 2874-0823   3 31 25.3  +43 55 26   13.180   0.606
                                               .026    .033
 142  GSC 2874-0657   3 31 09.9  +43 57 28   14.25    0.84
                                               .07     .11

remarks:
(1) - = HD 21629 = GSC 2874-0922.  observation on 1995 Sep 30.5 UT.
(2) - spec type A2
(3) - = GSC 2874-1540


Recent light curve from VSNET observations

Present light curve

light curve since 1995

this year


Light curves by VSOLJ

(by courtesy of VSOLJ)

1981-1996 (VSOLJ)

The 1986 outburst (VSOLJ)

The 1989 outburst (VSOLJ)

The 1992 outburst (VSOLJ)


Finding charts

wide-field chart

chart with Skiff's sequence

Skiff's sequence

Skiff's sequence, VSNET chart format


Return to HomePage


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