J/AJ/143/46 UBV photometry of stars in Berkeley 55 (Negueruela+, 2012)
The young open cluster Berkeley 55.
Negueruela I., Marco A.
<Astron. J., 143, 46 (2012)>
=2012AJ....143...46N 2012AJ....143...46N
ADC_Keywords: Clusters, open ; Photometry, UBV ; Spectral types ;
Cross identifications
Keywords: Galaxy: structure - open clusters and associations: individual
(Berkeley 55) - stars: early-type - stars: evolution - supergiants
Abstract:
We present UBV photometry of the highly reddened and poorly studied
open cluster Berkeley 55 (= C 2115+515), revealing an important
population of B-type stars and several evolved stars of high
luminosity. Intermediate-resolution far-red spectra of several
candidate members confirm the presence of one F-type supergiant and
six late supergiants or bright giants. The brightest blue stars are
mid-B giants. Spectroscopic and photometric analyses indicate an age
50±10Myr. The cluster is located at a distance d∼4kpc, consistent
with other tracers of the Perseus Arm in this direction. Berkeley 55
is thus a moderately young open cluster with a sizable population of
candidate red (super)giant members, which can provide valuable
information about the evolution of intermediate-mass stars.
Description:
UBV photometry of Berkeley 55 (J211659.9+514559.0) was obtained in
service mode using ALFOSC on the Nordic Optical Telescope (NOT) at the
Roque de los Muchachos Observatory (La Palma, Spain) on the night of
2010 June 14.
Taking into account the photometric spectral types and the position of
the stars in the color-magnitude diagrams (CMDs), we identify 138
likely members of Berkeley 55 (see table 5).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 59 237 The (X,Y) position on the map of all stars with
UBV photometry, together with their 2MASS
identification and their coordinates
table3.dat 42 237 Photometry for stars in Berkeley 55
table5.dat 27 138 Photometry and reddening for stars selected as
likely members of Berkeley 55
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
III/217 : Atlas of 840-880nm spectral region (Andrillat+ 1995-1997)
III/150 : Perkins Revised MK Types for the Cooler Stars (Keenan+ 1989)
J/MNRAS/389/285 : Proper motions & JHK of 24 Berkeley clusters (Tadross, 2008)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/237] Star number (<[NM2012] NNN> in Simbad)
5- 12 F8.3 pix Xpix X pixel coordinate
14- 21 F8.3 pix Ypix Y pixel coordinate
23- 32 F10.6 deg RAdeg [319.170/319.328]? Right Ascension (J2000)
34- 42 F9.6 deg DEdeg [51.714/51.8196]? Declination (J2000)
44- 59 A16 --- 2MASS 2MASS name (HHMMSSss+DDMMSSs; J2000, Cat. II/246)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/237] Star number (<[NM2012] NNN> in Simbad)
5- 10 F6.3 mag Vmag [13.286/20.281] The V band magnitude
12- 16 F5.3 mag e_Vmag The 1σ error in Vmag
18- 22 F5.3 mag B-V [0.73/2.841] The (B-V) color index
24- 28 F5.3 mag e_B-V The 1σ error in B-V
30- 34 F5.3 mag U-B [0.258/2.784]? The (U-B) color index
36- 40 F5.3 mag e_U-B ? The 1σ error in U-B
42 I1 --- Nm [1/4] Number of measurements
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/237] Star number, <[NM2012] NNN> in Simbad (1)
5- 8 F4.2 mag E(B-V) [1.55/2.29] The E(B-V) excess
10- 13 F4.2 mag e_E(B-V) The 1σ error in E(B-V)
15- 19 F5.2 mag V0mag [9.37/14.27] Intrinsic V band magnitude
21- 24 F4.2 mag e_V0mag The 1σ error in V0mag
26- 27 A2 --- SpT Photometric spectral type (b3 to a0)
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Note (1): The two known Be stars, S9 (no. 199) and S19 (no. 213) have been
left out, as their intrinsic color cannot be calculated.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 22-Apr-2013