COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                      Number 2121

                                 Konkoly Observatory
                                 Budapest
                                 1982 April 2

                                 HU ISSN 0374-0676





            SPECTRUM VARIABILITY OF HD 147010




   HD 147010 is an Ap Si star embedded in a reflection nebulosity in upper
Scorpius. In the course of investigating the spectral peculiarities of Ap stars
associated with nebulosities we found that HD 147010 shows spectrum variability.
The most drastic changes are exhibited by the lines of Cr II. Figure 1 shows
the density tracings of three of our blue plates in the region around 4000 A.
These spectra were obtained with the one meter telescope at Kavalur Observatory
at a dispersion of 22 A/mm.

                            [FIGURE 1]

   The line at 4012.5 is mainly due to Cr II which shows drastic changes;
strong on plate delta 1499, of intermediate strength on delta 1515 and weak on 
delta 1812.
The unidentified line at lambda 4002.9 shows variations opposite in phase to that
of lambda 4012.5.
A comparison of the measured radial velocities of our spectrograms with
that given by Abt (1973) does not indicate any variations more than those
ascribable to observational errors. We conclude that this star is probably
not a spectroscopic binary.
However, the variation in the line intensities is probably periodic.
A rough estimate based on the consideration of the rotational velocity of this
star together with the variation of the line strengths on our blue 
spectrograms indicates a period of 5.7 days.
   Since most of the spectrum variables also show variations in light, it
would be desirable to check the star for variability in light.





                            N. KAMESWARA RAO
                            and R. RAJAMOHAN


                        Indian Institute of Astrophysics
                         Bangalore - 560 034, India





Reference:
Abt, H.A.: 1973, Ap. J. Suppl. No. 26, 365 [BIBCODE 1973ApJS...26..365A ]