J/ApJ/576/880 CCD UBV photometry of h and χ Per (Slesnick+, 2002)
The star formation history and mass function of the double cluster
h and χ Persei.
Slesnick C.L., Hillenbrand L.A., Massey P.
<Astrophys. J. 576, 880 (2002)>
=2002ApJ...576..880S 2002ApJ...576..880S
ADC_Keywords: Clusters, open ; Photometry, CCD ; Photometry, UBV
Keywords: open clusters and associations: individual (NGC 869, NGC 884) -
stars: early-type - stars: luminosity function, mass function
Description:
The h and chi Per "double cluster" is examined using wide-field
(0.98x0.98°) CCD UBV imaging supplemented by optical spectra of
several hundred of the brightest stars.
The UBV photometry was obtained from observations with the 0.9m
telescope at Kitt Peak National Observatory using the Mosaic CCD
camera (0.43arcsec/pix) on 1999 February 3. Conditions were
photometric with a seeing about 1.3arcsec. The Mosaic camera consists
of eight individual SITe 2048x4096 CCD chips arranged in two rows of
four to produce a final image equivalent to 8192x8192 pixels
(098x098°) but with modest (35-50pix) gaps. Our imaging data set
contains short (0.5s in V and B and 2s in U), medium (2s in V and B
and 10s in U), and long (100s in V and B and 300s in U) integrations,
each consisting of five dithered exposures that were combined to fill
in gaps between the eight chips.
Analyzing the data near the cluster nuclei results in identical
reddenings E(B-V) (0.56±0.01), distance moduli (11.85±0.05), and
ages (12.8±1.0Myr) for the two clusters. In addition, the initial
mass function slope for each of the cluster nuclei is found to be
quite normal for high-mass stars (Γ=-1.3±0.2),
indistinguishable from a Salpeter value. The masses of the two
clusters are found to be 3700M☉ and 2800M☉ for h and χ
when integrating the present-day mass function from 1 to 120M☉.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 148 4528 Observational Data
table2.dat 40 279 Derived Quantities for Probable Cluster Members
table3.dat 40 411 Derived Quantities for Probable Field Stars
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See also:
J/A+A/372/477 : ubvyβ photometry of h + chi Persei (Marco+, 2001)
J/AJ/122/248 : h and chi Per UBVI,Hα photometry (Keller+, 2001)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- SHM Catalog Number ([SHM2002] in SIMBAD)
6 I1 h RAh Hour of Right Ascension (J2000)
8- 9 I2 min RAm Minute of Right Ascension (J2000)
11- 15 F5.2 s RAs Second of Right Ascension (J2000)
16 A1 --- DE- Sign of declination (J2000)
17- 18 I2 deg DEd Degree of Declination (J2000)
20- 21 I2 arcmin DEm Arcminute of of Declination (J2000)
23- 26 F4.1 arcsec DEs Arcsecond of Declination (J2000)
28- 33 F6.3 mag Vmag The visual magnitude
36- 41 F6.3 mag B-V The (B-V) color
44- 49 F6.3 mag U-B The (U-B) color
53- 57 F5.3 deg D-h Distance from the center of h Per
61- 65 F5.3 deg D-chi Distance from the center of Chi Per
67- 69 A3 --- Memb Cluster membership (1)
71- 79 A9 --- SpType Adopted MK Spectral Classification (2)
81-101 A21 --- SpType1 MK Spectral Classification from the
Literature (3)
104-148 A45 --- Onames Cross identifications from the Litterature (4)
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Note (1): Cluster membership:
far = not a member
h = h Per member
chi = chi Per member
Note (2): Note on SpType:
*: indicates that we used a spectral type from the literature in
our analysis.
Note (3): Reference code given in parentheses.
1 = Schild (1965ApJ...142..979S 1965ApJ...142..979S)
2 = Johnson & Morgan (1955ApJ...122..429J 1955ApJ...122..429J)
3 = Slettlebak (1968ApJ...154..933S 1968ApJ...154..933S)
4 = Appenzeller (1967PASP...79..102A 1967PASP...79..102A)
5 = Bidelman (1947ApJ...105..492B 1947ApJ...105..492B)
6 = Morgan, Code & Whitford (1955ApJS....2...41M 1955ApJS....2...41M)
Note (4): Our cross-identifications are not complete and focus on the
brighter stars and those for which we have spectral types. When
available, HD or BD numbers are given. All IDs marked "h-XXX" or
"chi-XXX" are from Wildey (1964ApJS....8..439W 1964ApJS....8..439W).
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Byte-by-byte Description of file: table2.dat table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- SHM The SHM catalog number ([SHM2002] in SIMBAD)
6- 7 A2 --- HRD [psa ] The HR diagram placement code (1)
9- 13 F5.3 [K] logT Log of the effective temperature
17- 20 F4.2 mag E(B-V) The (B-V) color excess
23- 27 F5.2 mag VMag The absolute V band magnitude
30- 34 F5.2 mag Mbol The bolometric absolute magnitude
37- 40 F4.1 solMass Mass Mass in solar units
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Note (1): HR diagram placement code:
p = star placed photometrically
s = star placed spectroscopically
a = the mean E(B-V) was adopted
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 26-Nov-2002