Is there any way I can tell from Hipparcos catalog which stars are Binary/Multiple Stars and which are Variable stars?
Yes. If you have the Hipparcos data from ftp (http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=I/239&-to=3), you will have several data files.
hip_main.dat you have a field
MultFlag at position 347 that indicates whether the star is a double or multiple star:
Note on MultFlag: indicates that further details are given in the Double and Multiple Systems Annex: C : solutions for the components G : acceleration or higher order terms O : orbital solutions V : variability-induced movers (apparent motion arises from variability) X : stochastic solution (probably astrometric binaries with short period)
To determine whether the star is a double or multiple star system, look in one of the files for double star solutions. For instance in
h_dm_com.dat there is a field at bytes 24-25 that gives the number of components (2 for double and >2 for multiple stars).
24- 25 I2 --- Ncomp Number of components in this solution (DCM2)
The Hipparcos number identifying the star can be found in bytes 43-48.
Of course this only works for multiple stars with orbital solutions.
For variability, three fields are provided in the main Hipparcos file:
314-320 F7.2 d Period ? Variability period (days) (H51) 322 A1 --- HvarType *[CDMPRU]? variability type (H52) 324 A1 --- moreVar * Additional data about variability (H53)
with two notes (NB. if
C then the star is constant, i.e. not variable!):
Note on HvarType: Hipparcos-defined type of variability (a blank entry signifies that the entry could not be classified as variable or constant): C : no variability detected ("constant") D : duplicity-induced variability M : possibly micro-variable (amplitude < 0.03mag) P : periodic variable R : V-I colour index was revised due to variability analysis U : unsolved variable which does not fall in the other categories Note on moreVar: more data about periodic variability are provided
There are two additional files on variability:
hip_va_2.dat, which provide information such as variable type (GCVS) and max and min magnitude and also the variable star name.
You can find a description of the variable type in the General Catalogue of Variable Stars (GCVS) in the file
vartype.txt if you download the GCVS at http://cdsarc.u-strasbg.fr/viz-bin/Cat?B/gcvs