NGC 5927 / C1524-505
RA: 15:28:00.69 DEC: -50:40:22.9  (J2000)

(Most recent updates: 
Membership probability flag - 2024; Remaining data - January 2025)
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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
=========================================================================
ID       Position               Mem   Period <mag>  ampl  C Type  Notes/
         RA          Dec        Flag                              Remarks
=========================================================================
1        15:28:15.17 -50:38:09.3 m1 ----     15.3   0.6   V Lb     
2        15:27:56.16 -50:40:34.4 m1 ----     15.2   0.6   V Lb
3        15:28:00.13 -50:40:24.6 m2 312.0    --     --      M             
4        15:28:06.97 -50:41:22.2 m1  67.0    15.2   1.0   V Lb 
5        15:27:56.56 -50:39:00.5 m1 ----     14.95  0.5   V Lb
6        15:27:57.13 -50:38:48.2 m1 ----     15.1   0.6   V Lb
7        15:28:02.81 -50:40:47.7 m1  70.0    15.3   0.6   V Lb
8        15:28:05.38 -50:38:50.0 m1  70.0    15.4   0.8   V Lb
9        15:28:01.72 -50:42:27.2 m1  85.0    15.75  0.9   V Lb
10       15:28:04.69 -50:39:55.4 m1 ----     15.1   0.4   V Lb    
11       15:27:44.92 -50:42:10.7 f  ----     15.1   0.4   V Lb    
FL01     15:27:48.93 -50:53:23.0 u  367.0    12.90  2.28  V M     mem?
FL07     15:28:00.78 -50:47:08.1 m1 242.0    15.75  2.46  V M     mem
FL08     15:28:02.37 -50:49:54.9 f   74.4    15.08  0.34  V SR    mem
FL11     15:26:33.10 -50:40:28.9 u  174.0    16.07  2.11  V M     mem?
FL13     15:28:24.27 -50:20:17.9 u  258.0    12.91  2.17  V M     mem?
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Supplementary Notes 

V1-11:
The RA and dec are from Samus et al. (2009).  All of the remaining data 
are from Lloyd Evans & Menzies (1977). Lloyd Evans & Menzies also 
listed magnitudes and colours for two additional red variables that were 
probable non-members.

FL01, FL07, FL08, FL11, FL13:
All of the data are from Layden et al. (2025, hereafter L25).
The periods, magnitudes, amplitudes and classifications listed are the
values L25 obtained from the ASAS-SN data base (Jayasinghe et al. 2020)
The comments on membership status in the Notes column are based on 
L25's analysis of Gaia DR3 proper motions and radial velocities (Gaia
Collaboration 2023). The membership flags in columns 34-35 were derived
from membership probabilities published by Vasiliev & Baumgardt (2021).

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Notes on individual stars

FL08:
      Vasilev & Baumgardt (2021) listed a 0% membership probability for
      this star. However, L25 did not agree with this conclusion.  Their
      analysis of Gaia DR3 radial velocity and CMD location led them to
      believe that FL08 is a likely member.

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Discovery of the variable stars in NGC 5927:

V1&2 = Fourcade #4 and #14 
  Fourcade et al. (1966) announced 15 variables in the field of NGC 5927
  and published x,y coordinates and an ID chart.
  Sawyer Hogg (1973) designated Fourcade's V4 and V14 as V1 and V2 in her
  3rd catalogue.

V3
  Osborn (1968) with x,y coordinates and an ID chart
  The number V3 was assigned by Sawyer Hogg (1973) in her 3rd catalogue.

V4-11 = V3, V6, V7, V8, V9, V10, L43, L17 of Lloyd Evans & Menzies 
  (1973), but no identification was provided by these authors.  
  After consultation with Lloyd Evans and Menzies, Sawyer Hogg (1973)
  assigned the numbers V4-11 in her 3rd catalogue and Menzies (1974)
  labelled them, along with V1 and V2, on an ID chart (see Plate II of his 
  paper). 


FL01, FL07, FL08, FL11, FL13
  These variables were among the 15 variables in NGC 5927 announced by 
  Fourcade et al. (1966), but because of their large angular offset from 
  the cluster centre, they were not included in Sawyer Hogg's (1973) 
  catalogue.  However, they have now been listed because L25 proposed 
  that their membership status should be revisited in view of 
  developments in the study of globular cluster structure since 1973 
  when Sawyer Hogg published her catalogue.


  L25 derived their RA and dec (J2000) by matching the stars in Fourcade's 
  charts with modern digital images.  They also listed their Gaia 
  Source IDs. 

  The Fourcade catalogue is not available in many libraries and has not 
  been digitized.  As a result,  many of the stars listed in their 
  catalogue will soon become lost to the literature on globular cluster 
  variable stars.
  For this reason, L25 also listed RA, dec and Gaia IDs for FL02, FL03,
  FL05, FL06, FL09, FL10, FL12 and FL15 in their paper.

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Liller (1983) conducted a search for RR Lyrae variables in NGC 5927, but
did not discover any.  The absence of RR Lyrae variables is not
surprising because the cluster CMD has a stubby red HB that does not 
extend into the instability strip.
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References

Fourcade, C. R., Laborde, J. R., Albarracin, J. 1966, Atlas y Catalogue
de Estrellas Variables en Cumulos Globulares al sur de -29 degrees, Cordoba

Gaia Collaboration: Vallenari, A., Brown, A. G. A. et al. 2023, A&A,
674, A1

Jayasinghe, T., Stanek, K. Z., Kochanek, C. S., Shappee, B. J.,
Holoien, T. EW.-S., Thompson, T. A., Prieto, J. L. and 9 coauthors,
2020, MNRAS, 491, 13

Layden, A. C., Revangelista, J., Gupta, S., Mittameda, M., Mulloy, E.,
Muslim, S. I., Olushola-Alao, T., Rishi, A. 2025, Astron. Nachr., 346, 
Issue 2

Liller, M. 1983, AJ, 88, 404

Lloyd Evans T. & Menzies, J. 1973, IAU Colloq. No. 21, Variable Stars in 
Globular Clusters and in Related Systems, 151`

Lloyd Evans T. & Menzies, J. 1977, MNRAS, 178, 163

Menzies, J. 1974, MNRAS, 169, 79

Osborn, W. 1968, Obs 88, 26 

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

Sawyer Hogg, H. 1973,  Publ. DDO, 3, No.6 

Vasiliev, E., Baumgardt, H. 2021, MNRAS, 505, 5978

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