COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 379

                                  Konkoly Observatory
                                  Budapest
                                  1969 September 15


         FLARE PHOTOMETRY OF V1216 SAGITTARII

      As part of the flare star observing programme at
Boyden Observatory, observations were made on V1216 Sagittarii
(R. A. 18h47.7m, Decl. -23deg32', visual magnitude 10.5) over
the period 4th to 17th July, 1969. The monitoring time and
flares are indicated in the following table, twelve flares
being recorded over a monitoring time of 25h11m.

        MONITORING TABLE OF V1216 SAGITTARII

DATE             TOTAL    FLARE   U.T. OF     Delta m     DURATION
1969   U.T.      HOURS     NO.     FLARE                   (MINS)          
July              PER                            
                 NIGHT
4 18h53m-19h39m  0h46m     -         -          -      -
6 19 42 -20 19   0 37      -         -          -      -
7 17 28 -21 57   4 29      1       17h34.25m  0.27   0.25
                           2       18 46. 5   0.23   2.0
                           3       19 09. 0   0.88   3.0
                           4       19 35.25   0.15   0.25
8 17 20 -21 55   4 35      5       18 48. 0   0.09   2.0
9 17 51 -20 08   2 17      9       18 01.75   0.24   3.75
                           7       19 48. 5   0.09   13.5
10 17 25-20 27
   20 37-20 55   3 20      8       17 48. 0    0.24   3.75
11 17 14-20 57   3 43      9       18 23.54    0.10   0.5
                           10      18 36. 1    0.13   0.3
16 17 00-19 37
   19 49-19 58   2 46      -         -         -      -
17 17 10-19 48   2 38      11      19 35. 0    0.21   11.3
                           12      18 31. 0    0.15   0.6
      TOTAL     25h11m

      The instrument used in this work was the 40 cm,
Nishimura Reflector fitted with a standard Johnson B. Filter.
As a detector we used a solid CO2 cooled E. M. I. 6256 
photomultiplier tube. The observing conditions were extremely
good and particularly noteworthy are the relatively long
duration low intensity minor flares, designated Nos. 7
and 11.

			[FIGURE 1-5]
			[FIGURE 6-8]

     As previously remarked on by Andrews (1966), it is
apparent that there is a tendency for flares to occur within
a few hours of one another - also there is further evidence
of the two day interval previously suspected from observations
of V1216 Sagittarii.
     For example - the interval between flares are as follows:

1 + 6 - 47h38m0s 	3 + 7 - 48h35m35s 	7 + 10 - 46h47m56s
3 + 8 - 48 48 45 	5 + 8 - 45 13 10    	8 + 11 -145 47 1
                                                8 + 12 -144 43 0

(for the last two flare intervals, the difference is nearly
144 hrs. i.e. 3 x 48 hrs.)

			[FIGURE 9-12]


Reference: Andrews, A. D. 1966. PASP 78, 542, [BIBCODE 1966PASP...78..542A ]

5th September, 1969


                      A. H. JARRETT,  J. P. EKSTEEN
                          Boyden Observatory,
                             Bloemfontein,
                         Republic of South Africa