NGC 6304 / C1711-294
RA: 17:14:32.25 DEC: -29:27:43.3 (J2000)
(Most recent updates:
Membership probability flag - 2024; Remaining data - February 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 17:14:40.47 -29:29:34.3 f 0.4722 15.846 0.820 I RR0 Og
2 17:14:18.69 -29:24:58.6 f 0.3989 15.533 0.865 I RR0 Og
3 17:14:47.57 -29:26:33.5 f 0.8555 15.392 0.487 I RR0 Og
4 17:14:11.58 -29:30:32.1 u 0.8123 14.904 0.376 I AC Note;Og
5 17:14:49.51 -29:27:40.9 f 0.4260 15.094 0.460 I E max
6 17:14:56.40 -29:30:38.8 u ---- -- -- CST H81
7 17:14:33.35 -29:32:28.0 f 0.5758 15.981 0.444 I RR0 Og
8 17:15:09.74 -29:26:30.5 u 0.6455 15.617 0.643 I RR0 Og
9 17:15:16.91 -29:23:23.7 u 0.3487 15.882 0.359 I RR1 Og
10 17:13:47.25 -29:32:18.9 u 0.6823 15.543 0.611 I RR0 Og
11 17:14:14.97 -29:36:53.9 u 264.75 15.80 1.02 V SR ASAS-SN
12 17:14:19.26 -29:19:42.2 u 285.0156 14.59 0.35 V SR ASAS-SN
13 17:14:20.61 -29:23:41.3 m1 ---- -- -- CST H81
14 17:14:23.14 -29:36:41.7 u ---- 16.4 1.2 B SR: H81
15 17:14:33.23 -29:25:48.4 m1 ---- -- -- CST? H81
16 17:14:41.79 -29:25:37.4 f ---- 14.35 2.32 V M: ASAS-SN
17 17:14:58.27 -29:30:42.7 u 302.8 12.196 2.573 I M Og
18 17:15:09.51 -29:27:36.1 u 139.49 11.815 2.307 I M Og
19 17:14:44.62 -29:35:45.4 u 487.4 13.065 3.697 I M Og
20 17:14:46.71 -29:36:45.5 u 152.02 13.097 0.218 I SR Og
21 17:15:10.19 -29:26:18.0 u 403.50 15.452 2.796 I M Og
22 17:14:37.67 -29:27:31.1 f 0.3380 15.197 0.207 I RR1 Og
23 17:14:27.33 -29:27:40.2 f 0.3940 15.642 0.118 I RR1 Og
24 17:14:48.89 -29:32:00.7 u 0.3698 15.417 0.244 I RR1 Og
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Supplementary Notes
The cluster NGC 6304 is a metal rich cluster located in a rich field
in the galactic bulge.
The first investigations of variable stars were by Rosino (1962) and
Terzan (1966, 1968). Although both authors announced the discovery of
variables, neither of them derived any periods.
A later study of the variables in NGC 6304 and the surrounding
field was by Hartwick et al. (1981). They derived periods for 40
RR Lyrae stars in their field and identified a number of other suspected
variables, many of which they classified as long period variables.
It is generally assumed that most of the variables belong to the field
around NGC 6304 and not to the cluster itself.
Since then, some of the variables have been recovered in other surveys
and the new results have been included in the above table.
V1-21:
The RA and dec are from Samus et al. (2009) who pointed out that all of
these variables have been assigned numbers in the Moscow General
Catalogue of Variable Stars as follows: V2167, V2161, V2171 Oph,
NSV 21164, V2173 Oph, NSV 21193, V2166, V2177, V2181, V2155, V2159,
V2160 Oph, NSV 08349, V2163 Oph, NSV 08361, V2169 Oph, NSV 08377,
V2180 Oph, NSV 08367, NSV 08369, NSV 08385.
The source for the remaining data is indicated in the Notes/Remarks
column where:
H81 refers to Hartwick et al. (1981)
Og refers to the OGLE survey
RR Lyrae - Soszynski et al (2019)
E - eclipsing - Soszynski et al. (2016)
AC - anomalous Cepheid - Soszynski et al. (2020)
SR - Soszynski et al. (2013)
M - Mira - Iwanek et al. (2022)
ASAS-SN - the All-Sky Survey for Supernovae ( Jayasinghe et al. 2108)
V22-24:
All of the data are from from the OGLE Bulge RR Lyrae investigation
(Soszynski et al. 2019).
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Notes on individual stars
V4: De Lee et al. (2006) concluded that this might be a cluster member
and suggested that it might be an anomalous Cepheid because its
light curve does not have the characteristic shape expected for
an RR Lyrae with such a long period.
It was initially listed as OGLE-BLG-RRLYR-00225 and classified as
RR0 by Soszynski et al. (2014).
However, in a later paper, Soszynski et al. (2020) listed it as
OGLE-GAL-ACEP-082, (10), an anomalous first-overtone Cepheid and
noted in their remarks that the star was previously listed as
OGLE-BLG-RRLYR-00225. Unfortunately, no data for this star was
included in their table for anomalous Cepheids (file acep.dat).
Therefore, the period, magnitude and amplitude data listed above
are from the 2014 paper.
Prudil & Arellano Ferro (2024) did not list a membership flag for
V4.
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Discovery of the variable stars in NGC 6304:
V1-11
Rosino (1962) with x,y coordinates and an ID chart
They are also listed in the Moscow GCVS as
Some of these variables are also in the OGLE Galactic Bulge
catalogue of RR Lyrae variables (Sosyzynski et al. 2014, 2019).
V1, 2, 3, 4*, 7, 8, 9, 10 are OGLE-BLG-RRLYR 00247, 00232, 00253,
00225, 00242, 16908, 16916 and 00201 respectively.
V4* was classified as an RR Lyrae variable in the 2014 paper, but
it was not included in the 2019 paper. It was subseqently classified
as an anomalous Cepheid and renamed OGLE-GAL-ACEP-82.
V5 is in the OGLE Galactic Bulge catalogue of eclipsing and
ellipsoidal binaries (Sosyzynski et al. 2016).
V5 is OGLE-BLG-ECL-002939
V11 is J171415.00-293654 in the ASAS-SN survey (Jayasinghe et al.
2018)
V12-18 = #28, 29, 30, 32, 33, 40, 43
Terzan (1966) with an ID chart
The numbers V12-18 were assigned by Sawyer Hogg (1973) in her 3rd
catalogue. Terzan announced 58 (V1-58) variables in his paper, but
Sawyer Hogg assigned numbers only to the ones that were located
within approximately 15 arcminutes of the cluster centre. The 2010
revision of the Harris (1996) catalogue inidcates a tidal radius of
13.25 arcminutes for NGC 6304.
V12 and V16 are J171419.31-291942.6 and J171441.88-292537.3
in the ASAS-SN survey (Jayasinghe et al. 2018)
V17 and V18 are OGLE-BLG-LPV-235217 and -235256
Layden et al. (2025) published RA, dec (J2000) and Gaia ID numbers
for four of the other variables announced by Terzan (1966): #45,
#47, #49 and #50.
V19-21 = #68, 69, 72 = OGLE-BLG-LPV-001373, -001391, and -235260
Terzan (1968) with an ID chart
The numbers V19-21 were assigned by Sawyer Hogg (1973) in her 3rd
catalogue. Terzan announced 25 new variables (V59-83) in his paper,
but Sawyer Hogg assigned numbers only to the ones within 15
arcminutes of the cluster centre.
V22-23 = #1247 & #4209, suspected variables
Hesser & Hartwick (1976) with ID chart
Their variability was later confirmed by De Lee et al. (2006).
Both stars were included in the OGLE III catalogue of RR Lyrae
variables as OGLE-BLG-RRLYR 00246 and 00237 respectively
(Sosyzynski et al. 2011).
The numbers V22 and V23 were assigned in this on-line
catalogue.
V24 = NV1
De Lee et al. (2006) with no ID or coordinates
However, based on the period they derived, this star appears to
be OGLE-BLG-RRLYR-00255 (Sosyzynski et al. 2011).
The number V24 was assigned in this on-line catalogue.
De Lee et al. included a few other 'new' RR Lyrae variables in
their investigation, but they did not consider any of them
to be possible cluster members. Therefore they are not listed
in the above table. These stars were listed as HBH67, Va46, NV2
which are the same stars as OGLE-BLG-RRLYR-00256,-00251 and -00238
respectively (Sosyzynski et al. 2011).
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References
de Lee, N., Catelan, M., Layden, A., Pritzl, B., Smith, H., Sweigart,
A., Welch, D. 2006, Mem SAI, 77, 117
Harris, W. E. 1996, AJ, 112, 1487
Hartwck, F. D. A., Barlow, D. J., Hesser, J. E. 1981, AJ, 86, 1044
Hesser, J. E. & Hartwick, F. D. A. 1976, ApJ, 203, 113
Iwanek, P., Soszynski, I., Kozlowski, S., Poleski, R., Pietrukoowicz,
P., Skowron, J., Wrona, M. and 8 coauthors, 2022, ApJS, 260, 461
Jayasinghe, T., Kochanek, C. S., Stanek, K. Z., Shappee, B. J., Holoien,
T. W.-S., Thompson, T. A., Prieto, J. L. and 7 coauthors, 2018, MNRAS,
477, 3145
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
Prudil Z., Arellano Ferro, A. 2024, MNRAS, 534, 3654
Rosino, L. 1962, Mem SAI, 33, 351 = Asiago-Padova Cont. 132
Samus, N. N., Kazarovets, E. V., Pastukhova, E. N., Tsvetkova, T. M.,
Durlevich, O. V. 2009, PASP, 121, 1378
Sawyer Hogg, H. 1973, Publ. DDO, 3, No. 6
Soszynski, I., Dziembowski, W. A., Udalski, A., Poleski, R., Szymanski,
M. K., Kubiak, M., Pietrzynski, G., Wyrzkowski, L., Ulaczyk, K.,
Kozlowski, S., Pietrukowicz, P. 2011, AcA, 61, 1
Soszynski, I., Pawlak, M., Pietrukowicz, P. Udalski, A., Szymanski,
M. K., Wyrzkowski, L., Ulaczyk, K and 6 coauthors, 2016, AcA, 66, 405
Soszynski, I., Udalski, A., Szymanski, M. K., Kubiak, M., Pietrzynski,
G., Wyrzykowski, L., Ulaczyk, K. and 4 coauthors, 2013, AcA, 63, 21
Soszynski, I., Udalski, A., Szymanski, M. K., Pietrukowicz, P. Z.,
Skowron, J., Skowron, D. M., Poleski, R. and 7 coauthors, 2020, AcA, 70, 101
Soszynski, I., Udalski, A., Szymanski, M. K., Pietrukowicz, P.,
Mroz, P., Skowron, J., Kozlowski, S. and 6 coauthors, 2014, AcA, 64, 177
Soszynski, I., Udalski, A., Wrona, M., Szymanski, M. K., Pietrukowicz, P.,
Skowron, J., Skowron, D. and 7 coauthors, 2019, AcA, 69, 321
Terzan, A. 1966, POHP, 9, 1
Terzan, A. 1968, POHP, 9, 24
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