J/MNRAS/174/471 Melotte 66 (Hawarden+, 1976)
The old open cluster Melotte 66.
Hawarden T.G.
<Mon. Not. R. Astron. Soc., 174, 471-487 (1976)>
=1976MNRAS.174..471H 1976MNRAS.174..471H
ADC_Keywords: Clusters, open ; Photometry, photographic
Abstract:
Photoelectric and photographic photometry of the open cluster Melotte
66 is presented. The CM diagram shows most of the characteristics of
an old cluster. The giant branch is broad with its blue edge populated
preferentially by stars from the outer parts of the cluster. There is
no detectable horizontal subgiant sequence. The main sequence turn-off
colour, two-colour diagram and the colour difference between the
turn-off and the subgiants are used to estimate the age and
composition. Melotte 66 appears to have reddening E(B-V)=0.17mag
and ultraviolet excess d(U-B)∼0.1mag corresponding to [Fe/H]=-0.3.
The cluster is probably between 6 and 7x109yr old. A distance
modulus (m-M)o=12.4mag is derived, which implies that the cluster
lies about 750pc from the galactic plane.
Description:
The observations were made with the Cape 100-cm and the Radcliffe
188-cm reflectors in 1970 and with the 100-cm telescope at the
Sutherland observing station of the SAAO in 1974. Reductions were
performed using mean extinction coefficients for each observing site
and transformations to the UBV system were determined for each
telescope-filter-photocathode combination from observations of
numerous E-region stars.
The positions were determined at CDS from the (x,y) positions
found at WEBDA, and a comparison with the printed finding chart.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 36 27 Photoelectrix results for stars in Melotte 66
table2.dat 181 370 Photographic magnitudes of stars within 5'
table3.dat 139 137 Photographic magnitudes of stars beyond 5'
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See also:
J/PASP/106/486 : Mel 66 CCD photometry (Anthony-Twarog+, 1994)
J/A+A/283/911 : Abundances in NGC 2243 and Mel 66 (Gratton+ 1994)
J/A+A/488/943 : Abundances of giants in four Galactic clusters (Sestito+ 2008)
J/A+A/566/A39 : UBVI photometry of Melotte 66 (Carraro+, 2014)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/322 : UCAC4 Catalogue (Zacharias+, 2012)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- ID Star identification, as in table 2 plus E stars
6- 10 F5.2 mag Vmag Johnson V-band photoelectric magnitude
11 A1 --- u_Vmag Uncertainty flag (:) on Vmag
12- 16 F5.2 mag B-V Johnson (B-V) color index
17 A1 --- u_B-V Uncertainty flag (:) on Vmag
18- 22 F5.2 mag U-B ?=- Johnson (U-B) color index
24 I1 --- n Number of observations
26- 30 A5 --- Tel Telescope(s) used (1)
32- 36 A5 --- Notes Remarks (2)
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Note (1): Telescopes are
R=Radcliffe 188cm;
C=Cape 100cm reflector;
S=Sutherland 100cm
Note (2): The remarks are:
M = Main sequence star
SG = subgiant
G = red giant star
HB = horizontal branch star
(1) = 4151 and 4152 measured together;
photographic measures of 4152 subtracted above.
(2) = Not used in photographic reductions.
(3) = Image double on deep plates; not used in photographic reductions.
(4) = Discordant photographic results; may be variable.
(5) = Smoothed (photographic) V = 14-70.
(6) = Smoothed (photographic) V = 17.48, B-V=0.68.
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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 --- ID [1101/4355] Star identification (1)
6- 10 F5.2 mag Vmag V-band photographic magnitude
12- 16 F5.2 mag B-V Photographic (B-V) color index
19- 22 I4 --- KJF [1/3727]? Star number in Kassis et al.
(1997AJ....113.1723K 1997AJ....113.1723K) (2)
24- 25 I2 h RAh Right Ascension J2000 (hours) (2)
27- 28 I2 min RAm Right Ascension J2000 (minutes) (2)
30- 35 F6.3 s RAs Right Ascension J2000 (seconds) (2)
37 A1 --- DE- Declination J2000 (sign) (2)
38- 39 I2 deg DEd Declination J2000 (degrees) (2)
41- 42 I2 arcmin DEm Declination J2000 (minutes) (2)
44- 48 F5.2 arcsec DEs Declination J2000 (seconds) (2)
50- 67 A18 --- 2MASS Star name in 2MASS-PSC (II/246) (2)
71- 80 A10 --- UCAC4 Star name in ICAC4 (I/322) (2)
83-181 A99 --- Comment Comment added at CDS (2)
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Note (1): The first digit represents a sector (1=NW, 2=NE, 3=SE, 4=SW);
the second digit represents a ring (1 for r≤3', 2 for 3'<r<5'),
the the 2 rightmost digits the number plotted on the chart.
Note (2): column added at CDS, using the (x,y) from WEBDA, and cross-matching
with 2MASS (II/246) and UCAC4 (I/322). The accuracy of the position is
better than 0.1arcsec from a comparison with astrometric catalogs.
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History:
* 15-Jul-2016: data acquired from the publication.
The positions were computed at CDS from the (x,y) positions found at
WEBDA (http://www.univie.ac.at/webda/cgi-bin/ocl_page.cgi?cluster=Mel66)
and a comparison with the printed finding chart.
(End) Francois Ochsenbein [CDS] 14-Jul-2016