NGC 6535 / C1801-003
RA: 18:03:50.69 DEC:  -00:17:48.9  (J2000)

(Most recent updates: 
Membership probability flag - 2024; Remaining data - March 2015)
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Bytes  Format      Explanation
1-8      A8        Star ID
10-32  A11,1x,A11  Position
34-35    A2        Membership probability flag based on data published
                   by Prudil & Arellano Ferro (2024)
                    m1: prob >=0.85;  m2: prob >=0.7 and <0.85;
                    m3: prob >= 0.5 and <0.7; f: prob <0.5
                    u:  no data available
37-44   F8.4       Period  (days)
46-51   F6.3       Mean magnitude (or maximum magnitude if "max" 
                      is indicated in the remarks column)
53-57   F5.3       Light amplitude (range of variability)
59      A1         Colour for mean magnitude and amplitude
                    e.g.  B, V, R, I, J, K
                    or P (for photographic).
61-65   A5         Type of variable (draft 2006 GCVS classifications)
                      CST denotes non variable stars previously designated
                      as variables
67-80   A19        Notes and Remarks  (f denotes field star)
 
 "--" or "----" indicates no data available
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ID       Position               Mem   Period <mag>  ampl  C Type  Notes/
         RA          Dec        Flag                              Remarks
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1        18:03:37.76 -00:16:47.9 f    0.5884 16.85  1.3   B RR0   f
2        18:03:41.39 -00:19:12.0 f    0.2735 17.15  0.5   B RR1   f
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Supplementary Notes 

A CM diagram by Sarajedini (1994) shows a predominanty blue HB and
significant population of blue straggler candidates.  The 2010 update to
the Harris (1996) catalogue lists [Fe/H] = -1.79.

The RA and dec for V1 and V2 are from Samus et al. (2009) and the other
elements are from Liller & Clement (1977).  The field status for both
variables is based on their location in the CM diagram of Liller (1980).
This status was confirmed by Prudil & Arellano Ferro (2024).
 
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Discovery of the variable stars in NGC  6535: 

  V1 = MO Ser
    Sawyer (1953) with x,y coordinates and an ID chart

  V2 = MP Ser
    Liller & Clement (1977) with x,y coordinates and an ID chart
    on which both V1 and V2 were labelled.

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Liller (1980) noted that star #41  (identified on an ID chart) might be
variable.  It lies near the RG tip in the CM diagram.
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References

Harris, W. E. 1996, AJ, 112, 1487

Liller, M. H., Clement,  C. C. 1977, AJ, 82, 965 

Liller, M. H. 1980, AJ, 85, 1480

Prudil Z., Arellano Ferro, A. 2024, MNRAS, 534, 3654

Samus, N. N., Kazarovets, E. V., Pastukhova, E. N., Tsvetkova, T. M.,
Durlevich, O. V. 2009, PASP, 121, 1378

Sarajedini, A. 1994, PASP, 106, 404

Sawyer, H. B. 1953, JRASC, 47, 229 
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