J/MNRAS/392/1456 VIc photometry of M50 (NGC 2323) low-mass stars (Irwin+, 2009)
The monitor project: rotation periods of low-mass stars in M50.
Irwin J., Aigrain S., Bouvier J., Hebb L., Hodgkin S., Irwin M., Moraux E.
<Mon. Not. R. Astron. Soc., 392, 1456-1466 (2009)>
=2009MNRAS.392.1456I 2009MNRAS.392.1456I
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; Photometry, CCD
Keywords: techniques: photometric - surveys - stars: pre-main-sequence -
stars: rotation - open clusters and associations: individual: M50
Abstract:
We report on the results of a time-series photometric survey of M50
(NGC 2323), a ∼130Myr open cluster, carried out using the Cerro Tololo
Inter-American Observatory (CTIO) 4-m Blanco telescope and Mosaic-II
detector as part of the Monitor project. Rotation periods were derived
for 812 candidate cluster members over the mass range
0.2≤M/M☉≤1.1. The rotation period distributions show a clear
mass-dependent morphology, statistically indistinguishable from those
in NGC 2516 and M35 taken from the literature. Due to the availability
of data from three observing runs separated by ∼10 and 1 month
time-scales, we are able to demonstrate clear evidence for evolution
of the photometric amplitudes, and hence spot patterns, over the 10
month gap. We are not able to constrain the time-scales for these
effects in detail due to limitations imposed by the large gaps in our
sampling, which also prevent the use of the phase information.
Description:
Photometric monitoring observations were obtained as part of the
Monitor project, using the 4-m Blanco telescope at Cerro Tololo
Inter-American Observatory (CTIO), with the Mosaic-II imager. A total
of ∼95h of photometric monitoring was conducted, spread over three
distinct observing runs: 6xfull-nights in two three-night segments
spanning 2005 February 04-06 and 2005 February 14-16, 8x1/2 nights
between 2005 December 24 and 2006 January 06 and 4xfull-nights between
2006 January 28 and 2006 February 01. M50 was observed in a single
telescope pointing centred on the cluster, for ∼8h per night
(∼4h per 1/2 night).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 119 812 Properties of our 812 rotation candidates
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See also:
J/A+AS/128/131 : UBV photometry of NGC 2323 (Claria+ 1998)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- [IAB2009] Identifier (M50-N-NNNN) (1)
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 22 F5.2 s RAs Right ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 34 F4.1 arcsec DEs [0/60] Declination (J2000)
36- 41 F6.3 mag Vmag Johnson V magnitude
43- 47 F5.3 mag e_Vmag rms uncertainty on Vmag
49- 54 F6.3 mag Icmag Cousins I magnitude
56- 60 F5.3 mag e_Icmag rms uncertainty on Imag
62- 67 F6.3 d Per Period
69- 74 F6.4 mag a1mag i-band instrumental α1 amplitude
76- 81 F6.4 mag e_a1mag rms uncertainty on a1mag
83- 88 F6.4 mag a2mag i-band instrumental α2 amplitude
90- 95 F6.4 mag e_a2mag rms uncertainty on a2mag
97-102 F6.4 mag a3mag i-band instrumental α3 amplitude
104-109 F6.4 mag e_a3mag rms uncertainty on a3mag
111-114 F4.2 solMass Mass Interpolated Mass (2)
116-119 F4.2 solRad Rad Interpolated Radius (2)
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Note (1): Our identifiers are formed using a simple scheme of the cluster
name, CCD number and a running count of stars in each CCD,
concatenated with dashes.
Note (2): From the models of Baraffe et al. (1998, Cat. J/A+A/337/403),
derived using the I magnitudes.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 18-Aug-2009