J/A+A/619/A132 Pseudo-photometric distances of 30 open clusters (Chelli+, 2018)
Pseudo-photometric distances of 30 open clusters.
Chelli A., Duvert G.
<Astron. Astrophys. 619, A132 (2018)>
=2018A&A...619A.132C 2018A&A...619A.132C (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, open ; Stars, distances
Keywords: stars: distances - methods: observational - methods: data analysis -
techniques: photometric
Abstract:
We demonstrate that reliable photometric distances of stellar
clusters, and more generally of stars, can be obtained using
pseudomagnitudes and rough spectral type without having to correct for
visual absorption.
We determine the mean absolute pseudomagnitude of all spectral
(sub)types between B and K. Distances are computed from the difference
between the star's observed pseudomagnitude and its spectral
type's absolute pseudomagnitude. We compare the distances of 30 open
clusters thus derived against the distances derived from TGAS
parallaxes.
Our computed distances, up to distance modulus 12, agree within 0.1mag
rms with those obtained from TGAS parallaxes, proving excellent
distance estimates. We show additionally that there are actually two
markedly different distances in the cluster NGC 2264.
We suggest that the pseudomagnitude distance estimation method, which
is easy to perform, can be routinely used in all large-scale surveys
where statistical distances on a set of stars, such as an open
cluster, are required.
Description:
Tables 1 and 2 show the computed pseudo-photometric distances of
thirty open clusters, selected from the analysis of more than 200
clusters, and their TGAS distances.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 108 19 Comparison between the pseudo-photometric and
TGAS distances for the 19 van Leeuwen et al.,
2017, Cat. J/A+A/601/A19 (fvl17) clusters
table2.dat 108 12 Comparison between the pseudo-photometric and
TGAS distances for 11 additional clusters
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/A+A/601/A19 : Gaia DR1 open cluster members (Gaia Collaboration+, 2017)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Cluster name
15- 23 A9 --- CName Cluster name
25- 30 F6.2 deg RAdeg Right ascension (J2000)
32- 37 F6.2 deg DEdeg Declination (J2000)
39- 44 F6.2 mas/yr pmRA Proper motion alogn RA, pmRA*cosDE
46- 49 F4.2 mas/yr e_pmRA rms uncertainty on pmRA
51- 56 F6.2 mas/yr pmDE Proper motion alogn DE
58- 61 F4.2 mas/yr e_pmDE rms uncertainty on pmDE
63- 67 F5.2 mag ppdm1 Pseudo-photometric distance without
proper motion constraint
69- 72 F4.2 mag e_ppdm1 rms uncertainty on ppdm1
73 A1 --- n_ppdm1 [*] Note on ppdm1 (1)
75- 77 I3 --- o_ppdm1 Number of star for ppdm1 calculation
79- 83 F5.2 mag ppdm2 ?=- Pseudo-photometric distance with
proper motion constraint
85- 88 F4.2 mag e_ppdm2 ?=- rms uncertainty on ppdm2
89 A1 --- n_ppdm2 [*] Note on ppdm2 (1)
91- 93 I3 --- o_ppdm2 ?=- Number of star for ppdm2 calculation
95- 99 F5.2 mag tgdm ?=- TGAS distance from van Leeuwen et al.,
2017, Cat. J/A+A/601/A19
101-104 F4.2 mag e_tgdm ?=- rms uncertainty on tgdm
106-108 I3 --- o_tgdm ?=- Number of star for tgdm calculation
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Note (1): * for pseudo-photometric distance retained.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 15-Nov-2018