J/A+A/390/931 VI photometry in Pismis 23 and Stephenson 2 (Ortolani+, 2002)
The very reddened open clusters Pismis 23 (Lynga 10) and Stephenson 2.
Ortolani S., Bica E., Barbuy B., Momany Y.
<Astron. Astrophys. 390, 931 (2002)>
=2002A&A...390..931O 2002A&A...390..931O
ADC_Keywords: Clusters, open ; Photometry
Keywords: open clusters and associations: individual: Pismis 23, Stephenson 2 -
stars: Hertzsprung-Russell (HR) and C-M diagrams
Abstract:
Pismis 23 and Stephenson 2 are two very reddened open clusters,
projected close to the Galactic plane. We present VI and JH photometry
for Pismis 23 and I and Gunn z for Stephenson 2. We derive a
relatively old age of ∼700Myr for Pismis 23, with a reddening value of
E(B-V)=1.73 and a distance d☉∼2.6kpc from the Sun. Stephenson 2
has a clump of red supergiants, indicating a young age of about 20Myr,
somewhat younger and more distant (d☉∼6kpc) than recently
reported in the literature. The age estimate for such a young object
is crucial for the distance estimate. The high reddening of these two
clusters relative to predictions from the diffuse interstellar medium
at their distances is due to discrete intervening clouds.
Objects:
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RA (2000) DE Designation(s)
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16 23 58 -48 53 33 Pismis 23
18 39 20 -06 01 44 Stephenson 2
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
pismis23.dat 48 5426 X,Y and V,I photometry of Pismis 23
stephen2.dat 37 2687 X,Y and I photometry of Stephenson 2
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Byte-by-byte Description of file: pismis23.dat
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Bytes Format Units Label Explanations
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1- 4 I4 ---- Seq Sequence number
9- 15 F7.2 pix Xpos x pixel coordinate in V image (1)
20- 26 F7.2 pix Ypos y pixel coordinate in V image (1)
32- 37 F6.3 mag Vmag V magnitude
44- 48 F5.3 mag V-Ic V-Ic colour index
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Note (1): 1 pix=0.39", north is up and east to the left.
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Byte-by-byte Description of file: stephen2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 ---- Seq Sequence number
9- 15 F7.2 pix Xpos x pixel coordinate as in Fig. 1 (1)
20- 26 F7.2 pix Ypos y pixel coordinate as in Fig. 1 (1)
32- 37 F6.3 mag Icmag Kron-Cousins I magnitude
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Note (1): 1 pix=0.37", north is up and east to the left.
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Acknowledgements: Beatriz Barbuy
(End) Patricia Bauer [CDS] 10-Jul-2002