J/AJ/167/262 LMI and LDT observation of Berkeley 50 members (Speckert+, 2024)
The Stellar Content of the Young Open Cluster Berkeley 50 (IC 1310).
Speckert M., Massey P., Skiff B.A.
<Astron. J., 167, 262 (2024)>
=2024AJ....167..262S 2024AJ....167..262S
ADC_Keywords: Clusters, open; Stars, B-type; Stars, supergiant; Photometry;
Spectra, optical; Parallaxes, trigonometric; Proper motions
Keywords: Open star clusters ; Red supergiant stars ; B stars
Abstract:
We observed the Galactic open cluster Berkeley-50 in order to
determine its stellar content, distance, and age. We obtained UBV
photometry of 1145 stars in a 12.3x12.3' field, and used Gaia proper
motions and parallaxes to identify 64 members, of which we obtained
spectra of the 17 brightest members. The majority of the observed
population we classified as Bdwarfs, with the exception of a newly
identified red supergiant star, which our spectroscopy shows has a
B-type companion. Our study establishes the distance as 3.8kpc, with
an average color-excess E(B-V)=0.9. Comparison of the physical
properties of the cluster with the Geneva evolutionary tracks places
the age of the cluster as 50-60Myr, with its most massive members
being ∼7M☉.
Description:
We obtained both UBV imaging data and follow-up spectroscopy with the
4.3m LDT located at Happy Jack, Arizona.
Images were taken on the LDT using the Large Monolithic Imager
(LMI).The images were kindly taken by Deidre Hunter prior to starting
their own observing, just as astronomical twilight ended on 2020
October 14, and consisted of a 0.5s exposure in V, a 2s exposure in B,
and a 10s exposure in U.
All the spectroscopy was carried out on the LDT using the DeVeny
optical spectrograph. The detector is a 2048x512e2v CCD42-10
deep-depletion device with 13.5um/pixels. A 600line/mm grating blazed
at 4900AA was used with a grating tilt of 26.95deg, which provided
wavelength coverage from 3700-5950AA and a dispersion of 1.12AA/pixel.
Objects:
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RA (2000) DE Designation(s)
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20 10 01.20 +34 58 01.1 Berkeley 50 = IC 1310
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 78 1145 Stars measured in our LMI field
table2.dat 48 64 Cluster members
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See also:
III/195 : Atlas of Optical Spectral Classification OB Stars (Walborn+ 1990)
II/183 : UBVRI Photometric Standards (Landolt 1992)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/ApJ/469/355 : Teff, B-V and BC relation (Flower, 1996)
J/AJ/113/1733 : Orion Nebula Cluster population (Hillenbrand 1997)
J/ApJ/576/880 : CCD UBV photometry of h and χ Per (Slesnick+, 2002)
J/MNRAS/389/285 : Proper motions & JHK of 24 Berkeley clusters (Tadross, 2008)
J/A+A/537/A146 : Stellar models with rot. 0.8<M<120, Z=0.014 (Ekstrom+, 2012)
J/A+A/543/A156 : Milky Way global survey of star clusters (Kharchenko+, 2012)
J/AJ/156/121 : Catalog of 518 likely open cluster NGC6405 member (Gao, 2018)
J/ApJ/873/91 : Interferometric obs. B-type stars with CHARA (Gordon+, 2019)
J/ApJ/875/124 : Binary red supergiants. II. Btype companions (Neugent+, 2019)
J/A+A/640/A1 : Portrait Galactic disc (Cantat-Gaudin+, 2020)
J/ApJ/900/118 : RSGs in LMC & sp. follow-up for LMC & SMC (Neugent+, 2020)
J/MNRAS/504/356 : Updated parameters of 1743 open clusters (Dias+, 2021)
J/ApJ/908/87 : 182 RSGs and OB-stars in M31 and M33 (Neugent, 2021)
J/A+A/673/A114 : Improving the open cluster census. II. (Hunt+, 2023)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Star identifier
11- 14 F4.2 arcmin rho [0.1/8.83] Angular separation from the RSG
16- 17 I2 h RAh [20] Hour of Right Ascension (J2000)
19- 20 I2 min RAm [9/10] Minute of Right Ascension (J2000)
22- 26 F5.2 s RAs Second of Right Ascension (J2000)
28 A1 --- DE- [+] Sign of declination (J2000)
30- 31 I2 deg DEd [34/35] Degree of Declination (J2000)
33- 34 I2 arcmin DEm Arcminute of Declination (J2000)
36- 39 F4.1 arcsec DEs Arcsecond of Declination (J2000)
41- 45 F5.2 mag Vmag [10.6/19.7] Apparent V magnitude
47- 50 F4.2 mag B-V [0.17/2.79] B-V color
52- 58 F7.4 mas plx [-0.62/5.87]? Gaia DR3 parallax (1)
60- 64 F5.2 mas/yr pm [0.1/53.1]? Gaia DR3 proper motion (1)
66- 71 F6.2 mas/yr pmRA [-52.76/29.45]? Gaia DR3 proper motion in Right
Ascension (1)
73- 78 F6.2 mas/yr pmDE [-39.66/18.29]? Gaia DR3 proper motion in
Declination (1)
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Note (1): Reference: Gaia Collaboration+, 2023A&A...674A...1G 2023A&A...674A...1G.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Star identifier
11- 20 A10 --- SpType Spectral type
22- 26 F5.2 mag Vmag [11.96/18.74] Apparent V magnitude
28- 31 F4.2 mag B-V [0.63/2.06] B-V color
33- 37 F5.2 mag VMag [-3.73/3.05] Absolute V magnitude
39- 43 F5.3 [K] [Teff] [3.58/4.184] Log of effective temperature
45- 48 F4.2 [Lsun] [Lum] [0.76/3.8] Log of luminosity
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 14-Jun-2024