J/MNRAS/423/2966 Low-mass stars spectroscopy in NGC 2516 (Jackson+, 2012)
Why do some young cool stars show spot modulation while others do not?
Jackson R.J., Jeffries R.D.
<Mon. Not. R. Astron. Soc., 423, 2966-2976 (2012)>
=2012MNRAS.423.2966J 2012MNRAS.423.2966J
ADC_Keywords: Clusters, open ; Photometry ; Radial velocities ;
Equivalent widths
Keywords: stars: low-mass - stars: magnetic field - stars: rotation -
open clusters and associations: individual: NGC 2516
Abstract:
We present far-red, intermediate-resolution spectroscopy of 572
photometrically selected, low-mass stars (0.2<M/M☉<0.7) in the
young open cluster NGC 2516, using the FLAMES spectrograph at the Very
Large Telescope. Precise radial velocities confirm membership for 210
stars that have published rotation periods from spot-modulated light
curves and for another 144 stars in which periodic modulation could
not be found. The two subsamples are compared and no significant
differences are found between their positions in colour-magnitude
diagrams, the distribution of their projected equatorial velocities or
their levels of chromospheric activity.
Description:
Targets for our spectroscopic survey were selected from Irwin et al.
(2007, Cat. J/MNRAS/377/741) with 14<I<19. They were observed using
the European Southern Observatory (ESO) 8.2-m aperture Very Large
Telescope (UT-2 Kueyen) FLAMES fibre instrument, feeding the GIRAFFE
and UVES spectrographs. Multiple targets were observed with GIRAFFE in
eight separate fibre configurations.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 96 572 Velocity data measured for targets in NGC 2516
table4.dat 90 572 Chromospheric activity indices and related data
--------------------------------------------------------------------------------
See also:
J/MNRAS/377/741 : VIc photometry of NGC 2516 (Irwin+, 2007)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- --- [N2516-]
7- 14 A8 --- [IHA2007] Identification number, N-N-NNNN,
<[IHA2007] 2516-N-N-NNNN> in Simbad
17 I1 h RAh Right ascension (J2000)
19- 20 I2 min RAm Right ascension (J2000)
22- 26 F5.2 s RAs Right ascension (J2000)
28 A1 --- DE- Declination sign (J2000)
29- 30 I2 deg DEd Declination (J2000)
32- 33 I2 arcmin DEm Declination (J2000)
35- 39 F5.2 arcsec DEs Declination (J2000)
41- 46 F6.3 d Per ?=- Modulation period
48- 52 F5.2 mag Vmag V magnitude
54- 58 F5.2 mag Icmag Cousins C magnitude
60- 64 F5.2 mag Kmag ?=- CIT K magnitude (1)
66- 67 I2 --- SNR Signal-to-noise ratio
69- 74 F6.2 km/s RV Radial velocity
76- 79 F4.1 km/s e_RV rms uncertainty on RV
81 A1 --- l_vsini Limit flag on vsini
82- 86 F5.1 km/s vsini Rotational velocity
88- 90 F3.1 km/s e_vsini ?=- rms uncertainty on vsini
92- 94 A3 --- Run Run number(s)
96 A1 --- Mm [*] * for non-members
--------------------------------------------------------------------------------
Note (1): K magnitudes from the 2MASS transformed to the CIT system
using K(CIT)=K(2MASS)+0.024. For the sources N2516-1-4-4069,
N2516-2-2-1247, N2516-2-2-19, N2516-2-3-1199, N2516-3-1-2708 and
N2516-3-7-689, original value was .020, transformed into ---.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- --- [N2516-]
7- 14 A8 --- [IHA2007] Identification number, N-N-NNNN,
<[IHA2007] 2516-N-N-NNNN> in Simbad
16- 20 F5.2 [Lsun] logL Luminosity
22- 27 F6.3 d Per ?=- Modulation period
29- 33 F5.3 mag amp ?=- sine amplitude (light curve amplitude)
35- 37 I3 d tc Convective turn-over time τc
39- 43 F5.2 [-] logR ?=- Rossby number
45- 49 F5.2 0.1nm W(Ca)1 Ca 8498Å equivalent width
51- 54 F4.2 0.1nm e_W(Ca)1 rms uncertainty on W(Ca)1
56- 60 F5.2 0.1nm W(Ca)2 Ca 8542Å equivalent width
62- 65 F4.2 0.1nm e_W(Ca)2 rms uncertainty on W(Ca)2
67- 71 F5.2 [-] logR'1 ?=- Activity index from Ca8488
73- 75 F3.2 [-] e_logR'1 ?=- rms uncertainty on logR'1
77- 81 F5.2 [-] logR'2 ?=- Activity index from Ca8542
83- 85 F3.2 [-] e_logR'2 ?=- rms uncertainty on logR'2
87- 90 F4.2 Msun Mass Mass
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 04-Apr-2013