Proper motion of the GSC 2503-0182

This star (GSC 2503-0182, Hipparcos H 49066, Tycho T 2503-1517-1) have an unusual proper motion according to measures of the Hipparcos satellite.

I was observed the field of this star at night 2002-03-18/19. The first inspection leads to great misidentification of my image and image by the Digitized Sky Survey (converted to PNG is here). Please, identify move star.


The results from the Hipparcos mission gives for the star (J1991.25):

H 49066    mu_a = -1008.34 +- 3.11 mas/year
           mu_d =  -663.34 +- 2.11 mas/year

the proper motion is 1.20713 "/year.


The plate was been acquired at 1955-04-14 so epoch is 1955.29. The coordinate are (gaia's centroids): 10:00:47.805 and 32:19:03.55. The GSC coordinates derived from the Palomar (?) are for another epoch.

Our measures

We have coordinates for epoch 2002.22: 10:00:44.170 and 32:18:32.60. The differences: 54.525 (alpha) and 30.95 (delta) with coordinate fit error 0.2". The

The results

The time difference is 46.93 years.

mu_a   -1161.84 mas/year +- 4.3
mu_d    -659.49 mas/year +- 4.3

Proper motion is 1.33596 "/year +- 0.00061.

The End

My and Hipparcos results are non-consistent. The difference may be due error in my data, due to nonlinear motion of the star or some systematics errors of the calibrations of the Hipparcos data.

I will be re-observe this object in future.

Also see Hipparcos: High Proper Motion Stars