[vsnet-obs 57902] GW Librae, 2007 Apr 14-15 UT (GRL, NAS.VSS).

[Bjorn H. Granslo]

Norwegian Astronomical Society - Variable Star Section

Observations of the recurrent cataclysmic object GW Librae.

Time interval: 2007 Apr 14 UT - 2007 Apr 15 UT
Observer: B. H. Granslo (GRL).
Locations: Fjellhamar, Norway.
Observations: Visual, Pogson step estimates.
Instrument: 20.3-cm SCT (C203).

Variable  YYYYMMDD.DDD  Magn  Obs  Instrum.   Mag.ref. Estimates [Class]
LIBGW     20070414.049   8.5  GRL  C203;100x  NAS.VSS  E=V;F+5 [1]
LIBGW     20070415.044   8.7  GRL  C203;133x  NAS.VSS  E-2;G+5 [1]

Remarks:
GW Librae was easily visible despite a maximum altitude of 5 degrees.

NAS.VSS comparison stars (V-magnitudes from GCPD and Tycho-2 w/Bessell):
E = HD 135812 (V = 8.50); F =  HD 135327 (V = 8.99);
G = HD 136234 AB (V = 9.19).

V-magnitudes of stars E and G were from Slawson et al. (1992, Astrophys.
Journ. Suppl. 82, 117), while that of star F were from Tycho-2 w/Bessell.

(Sequence at http://www.astro.uio.no/~bgranslo/sequence/GW_Lib.seq .)

                                     Yours sincerely,
                                     Bjorn H. Granslo