J/AJ/122/248 h and chi Per UBVI,Hα photometry (Keller+, 2001)
UBVI and Hα photometry of the h and χ Persei cluster.
Keller S.C., Grebel E.K., Miller G.J., Yoss K.M.
<Astron. J. 122, 248 (2001)>
=2001AJ....122..248K 2001AJ....122..248K
ADC_Keywords: Clusters, open ; Photometry, UBVRI ; Photometry, H-alpha ;
Stars, Be
Keywords: open clusters and associations: individual (NGC 869, NGC 884) -
stars: emission-line, Be - stars: evolution - techniques: photometric
Abstract:
UBVI and Hα photometry is presented for 17319 stars in vicinity
of the young double cluster h and χ Persei. Our photometry extends
over a 37'x1° field centered on the association. We construct
reddening contours within the imaged field. We find that the two
clusters share a common distance modulus of 11.75±0.05 and ages of
log[age(yr)]=7.1±0.1. From the V-Hα color, a measure of the
Hα emission strength, we conduct a survey for emission line
objects within the association. We detect a sample of 33 Be stars,
eight of which are new detections. We present a scenario of
evolutionary enhancement of the Be phenomenon to account for the peak
in Be fraction toward the top of the main sequence in the population
of h and χ Persei and similar young clusters.
UBVI and Hα photometry was performed on five nights between 1999
August 17 and 25 at the San Diego State University Mount Laguna
Observatory with the 1m telescope and a Loral 2048x2048 CCD.
Objects:
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RA (2000) DE Designation(s)
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02 22 24 +57 07.0 NGC 884
02 19 00 +57 09.0 NGC 869
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 100 5 Atmospheric extinction coefficients and photometric
zero points from the present study
table2.dat 74 17315 Photometric data
table4.dat 74 33 Be stars detected within the field of h and χ Per
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See also:
J/A+A/372/477 : ubvyβ photometry of h + chi Persei (Marco+, 2001)
J/A+AS/119/271 : Be stars uvbyβ photometry (Fabregat+, 1996)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "YYYY/MM/DD" Date Observation date
12- 16 F5.3 mag k1,V Atmospheric extinction coefficient in V band
18- 22 F5.3 mag e_k1,V rms uncertainty on k1,V
24- 28 F5.3 mag k1,B Atmospheric extinction coefficient in B band
30- 34 F5.3 mag e_k1,B rms uncertainty on k1,B
36- 39 F4.2 mag k1,U Atmospheric extinction coefficient in U band
41- 44 F4.2 mag e_k1,U rms uncertainty on k1,U
46- 50 F5.3 mag K1,I Atmospheric extinction coefficient in I band
52- 56 F5.3 mag e_K1,I rms uncertainty on k1,I
58- 62 F5.3 mag ksiV Photometric zero point in V band
64- 68 F5.3 mag e_ksiV rms uncertainty on ksiV
70- 74 F5.3 mag ksiB Photometric zero point in B band
76- 80 F5.3 mag e_ksiB rms uncertainty on ksiB
82- 85 F4.2 mag ksiU Photometric zero point in U band
87- 90 F4.2 mag e_ksiU rms uncertainty on ksiU
92- 96 F5.3 mag ksiI Photometric zero point in I band
97-100 F4.2 mag e_ksiI rms uncertainty on ksiI
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Byte-by-byte Description of file: table2.dat table4.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- [KGM2001] Identification number
7- 15 F9.3 pix Xpix X pixel position (1)
17- 25 F9.3 pix Ypix Y pixel position (1)
28- 33 F6.3 mag Vmag The V-band magnitude
36- 41 F6.3 mag U-B The U-B color
44- 49 F6.3 mag B-V The B-V color
52- 57 F6.3 mag V-I The V-I color
60- 65 F6.3 mag V-Ha The V-Hα color
67- 68 A2 --- Be [Be] Be: Be star
71- 74 I4 --- Oos ? The Oosterhoff (1937AnLei..17a...1O 1937AnLei..17a...1O)
identification number (2)
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Note (1): The scale is 1 pix = 0.399"
Note (2): Identifications:
NGC 869 NNNN (for Nos 1-1640, 4000-4090), h Per
NGC 884 NNNN (for Nos 1641-2987, 7001-7125), chi Per
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 14-Jan-2002