VY LMi

RA/DEC (2000) 09:27:41.30 DEC +36:58:22.3

VY LMi has been shown to be a RRab star by Henden and Vidal-Sainz (1997). It was formerly designated as a NSV star suspected to be a cepheid. They found the following elements:

HJD 2450487.507 + 0.526146 E
Its variation is between 12.85 and 13.95 in V filter.

Henden and Vidal-Sainz (1997) also have calibrated some stars in VY LMi field: see table below.

Wils et al. (2006) report observations from ROTSE telescope and derive new elements:

HJD 2451598.2 + 0.52614 E

Finding chart from Henden and Vidal-Sainz (1997). North is on top

Star GSC V (U-B) (B-V) (V-R) (R-I)

A 2500.0125 14.882±0.008 0.191±0.010 0.723±0.009 0.377±0.010 0.364±0.007

B 2500.0275 14.398±0.003 0.441±0.012 0.835±0.004 0.464±0.003 0.444±0.003

C 2500.0375 14.401±0.003 0.685±0.013 1.115±0.007 0.613±0.004 0.589±0.004

D 2500.0413 14.491±0.002 0.130±0.006 0.666±0.003 0.382±0.003 0.359±0.004

E 2500.0557 14.953±0.005 0.112±0.008 0.636±0.006 0.371±0.005 0.340±0.005

F 2500.1161 15.003±0.004 0.154±0.007 0.671±0.006 0.369±0.004 0.341±0.005

G 2500.1185 14.723±0.006 0.038±0.005 0.672±0.007 0.384±0.006 0.364±0.008

Comparison stars photometry (Henden and Vidal-Sainz, 1997)

Laurent Corp, Etienne Morelle and Alain Bruno have observed VY LMi with the 60cm telescope at Pic du Midi Observatory during 3 nights between 2008 February 12 and 16. through a V filter.

Observation log

date Julian day Observer/site number filter

of measurements

12 February 2008 2454508 Laurent Corp, Etienne Morelle, Alain Bruno /T60, Pic du Midi 18 V

13 February 2008 2454509 Laurent Corp, Etienne Morelle, Alain Bruno /T60, Pic du Midi 43 V

16 February 2008 2454512 Laurent Corp, Etienne Morelle, Alain Bruno /T60, Pic du Midi 43 V

Laurent Corp and collaborators have observed one maximum on 2008 February 13 at HJD 2454509.3715 ± 0.0009. The folded light curve shows that the elements from Henden and Vidal-Sainz (1997) are still up to date. Wils et al.'s (2006) elements are not as precise as shown in O-C diagrams below.

O-C diagram according to elements from
Henden and Vidal-Sainz (1997)

O-C diagram according to elements from
Wils et al.'s' (2006)

date	Julian day	Observer/site	number	filter
			of measurements
12 February 2008	2454508	Laurent Corp, Etienne Morelle, Alain Bruno /T60, Pic du Midi	18	V
13 February 2008	2454509	Laurent Corp, Etienne Morelle, Alain Bruno /T60, Pic du Midi	43	V
16 February 2008	2454512	Laurent Corp, Etienne Morelle, Alain Bruno /T60, Pic du Midi	43	V

	Laurent Corp and collaborators have observed one maximum on 2008 February 13 at HJD 2454509.3715 ± 0.0009. The folded light curve shows that the elements from Henden and Vidal-Sainz (1997) are still up to date. Wils et al.'s (2006) elements are not as precise as shown in O-C diagrams below.

O-C diagram according to elements from Henden and Vidal-Sainz (1997)	O-C diagram according to elements from Wils et al.'s' (2006)