J/AJ/150/134 uvbyCaHβ photometry of NGC 752 (Twarog+, 2015)
A uvbyCaHβ CCD analysis of the open cluster standard NGC 752.
Twarog B.A., Anthony-Twarog B.J., Deliyannis C.P., Thomas D.T.
<Astron. J., 150, 134 (2015)>
=2015AJ....150..134T 2015AJ....150..134T (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, nearby ; Photometry, CCD ;
Photometry, uvby, beta
Keywords: open clusters and associations: general -
open clusters and associations: individual: NGC 752
Abstract:
Precision uvbyCaHβ photometry of the nearby old open cluster,
NGC752, is presented. The mosaic of CCD fields covers an area ∼42' on
a side with internal precision at the 0.005-0.010mag level for the
majority of stars down to V∼15. The CCD photometry is tied to the
standard system using an extensive set of published photoelectric
observations adopted as secondary standards within the cluster.
Multicolor indices are used to eliminate as nonmembers a large
fraction of the low probability proper-motion members near the faint
end of the main sequence, while identifying 24 potential dwarf members
between V=15.0 and 16.5, eight of which have been noted before from
Vilnius photometry. From 68 highly probable F dwarf members, we derive
a reddening estimate of E(b-y)=0.025±0.003 (E(B-V)=0.034±0.004),
where the error includes the internal photometric uncertainty and the
systematic error arising from the choice of the standard (b-y,Hβ)
relation. With reddening fixed, [Fe/H] is derived from the F dwarf
members using both m1 and hk, leading to [Fe/H]=-0.071±0.014(sem)
and -0.017±0.008(sem), respectively. Taking the internal precision
and possible systematics in the standard relations into account,
[Fe/H] for NGC 752 becomes -0.03±0.02. With the reddening and
metallicity defined, we use the Victoria-Regina isochrones on the
Stromgren system and find an excellent match for (m-M)=8.30±0.05 and
an age of 1.45±0.05Gyr at the appropriate metallicity.
Description:
Intermediate and narrow-band images of NGC752 were obtained using the
WIYN 0.9m telescope during three observing runs in 2010 November, 2012
November and 2013 December.
For the first two observing runs, the S2KB CCD was used at the f/7.5
focus of the telescope for a 20'*20' field with 0.6'' pixels. All
seven filters were from the 3''*3'' filter set owned jointly by the
University of Kansas and Mt. Laguna Observatory. For the 2013 December
run, the telescope was equipped with the Half-Degree-Imager (HDI), a
4K*4K chip with a 29'*29' field with 0.43'' pixels. The seven filters
were from the extended Stromgren set recently acquired for specific
use with the HDI.
Final photometry on the uvbyCaHβ system can be found in Table4.
See also:
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
II/215 : uvby-beta Catalogue (Hauck+ 1997)
J/MNRAS/446/3562 : Abundances of red giants in NGC752 (Bocek Topcu+, 2015)
J/AJ/148/51 : WOCS. LXI. NGC 6819 photometry (Anthony-Twarog+, 2014)
J/AJ/142/127 : NGC 5822 UBVI and uvbyCaHβ photometry (Carraro+, 2011)
J/BaltA/20/27 : NGC 752 Vilnius photometry (Bartasiute+, 2011)
J/BaltA/19/35 : NGC 752 Vilnius photometry (Zdanavicius+, 2010)
J/ApJS/176/262 : VRI phot. and theta values in open clusters (Taylor+, 2008)
J/AJ/127/1000 : Stromgren and Ca photometry of NGC3680 (Anthony-Twarog+, 2004)
J/AJ/119/2282 : Stromgren photometry of IC 4651 (Anthony-Twarog+, 2000)
J/A+A/339/423 : Velocities of red giants in NGC 752 (Mermilliod+ 1998)
J/PASP/106/281 : Photometry and radial velocities in NGC752 (Daniel+, 1994)
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table4.dat 144 1590 Photometry in NGC 752
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 9 F8.6 h RAhour Right Ascension in decimal hours (J2000)
11- 18 F8.5 deg DEdeg Declination in decimal degrees (J2000)
20- 25 F6.3 mag Vmag [7.1/18] The V band magnitude
27- 32 F6.3 mag b-y [0.01/1.2] The Stromgren (b-y) color index
34- 39 F6.3 mag m1 [-0.1/0.85]?=9.999 The Stromgren metallicity index
m1=(v-b)-(b-y)
41- 46 F6.3 mag c1 [-0.22/1.12]?=9.999 The Stromgren discontinuity
index c1=(u-v)-(v-b)
48- 53 F6.3 mag hk [0.16/2.1]?=9.999 The Stromgren hk index
55- 60 F6.3 mag Hb [2.38/9.84]?=9.999 The Hβ index
62- 66 F5.3 mag e_Vmag [0/0.05] Uncertainty in Vmag
68- 72 F5.3 mag e_b-y [0.001/0.07] Uncertainty in b-y
74- 78 F5.3 mag e_m1 ?=9.999 Uncertainty in m1
80- 84 F5.3 mag e_c1 ?=9.999 Uncertainty in c1
86- 90 F5.3 mag e_hk ?=9.999 Uncertainty in hk
92- 96 F5.3 mag e_Hb ?=9.999 Uncertainty in Hb
98- 99 I2 --- Ny [2/65] Number of y filter observations
101-102 I2 --- Nb [2/66] Number of b filter observations
104-105 I2 --- Nv [0/50] Number of v filter observations
107-108 I2 --- Nu [0/51] Number of u filter observations
110-111 I2 --- NCa [0/64] Number of Ca filter observations
113-114 I2 --- Nn [0/38] Number of Hβ narrow filter
observations
116-117 I2 --- Nw [0/39] Number of Hβ wide filter observations
119-122 I4 --- WEBDA [0/7699] Identification in WEBDA
(http://www.univie.ac.at/webda)
124-127 I4 --- P91 [0/1229] Identification, Platais
(1991A&AS...87...69P 1991A&AS...87...69P)
129-131 I3 --- H26 [0/395] Identification, Heinemann
(1926AN....227..193H 1926AN....227..193H)
133-135 I3 --- RV61 [0/410] Identification, Rohlfs & Vanysek 1961
(Astr. Abh. Hambourg Vol. No. 7)
137-139 I3 --- S85 [0/410] Identification in Stock
(1985RMxAA..11..103S 1985RMxAA..11..103S)
141-142 I2 % Mm [-1/99] Membership probability from Platais
(1991A&AS...87...69P 1991A&AS...87...69P) (1)
144 A1 --- Class Calibration equation class (B, D, or G) (2)
--------------------------------------------------------------------------------
Note (1): Stars without membership data are assigned -1.
Note (2): The codes corresponding to the diagram fields are defined as below:
B = "Blue" field (b-y<0.45);
D = "cooler Dwarf" field (b-y≥0.45);
G = Giant ("cooler evolved" field).
--------------------------------------------------------------------------------
History:
14-Apr-2016: From electronic version of the journal
26-Sep-2021: units of RA corrected (hours instead of degrees)
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 11-Apr-2016