II/46 Strong cyanogen stars (McClure 1970)
A Photometric Investigation of the Strong Cyanogen Stars, Table 1: Bright
Calibration Stars; Table 4: Strong Cyanogen Stars
McClure R.D.
<Astron. J., 75, 41 (1970)>
=1970AJ.....75...41M 1970AJ.....75...41M
ADC_Keywords: Photometry, CN band; Colors; Stars, cyanogen
Description:
A cyanogen index for late-type giants, insensitive to surface gravity
but sensitive to metallicity, is presented in the David Dunlap
Observatory (DDO) photometric system. Observations were made using
conventional single-channel photometers with 1P21 photomultiplier
tubes on the 40cm and 90cm telescopes of Kitt Peak National
Observatory. The original DDO filter set C was used (see Paper I,
1968AJ.....73..313M 1968AJ.....73..313M).
Table 1 contains DDO photometry on 52 bright late-type giants for
calibration. Most G8 to M0 stars, luminosity class III, V<4.0mag,
north of δ=-10°, supplement the original stars from Paper I.
Table 4 includes both DDO and UBV photometry for stars from Schmitt
(1967 thesis, Univ. Michigan, Ann Arbor) and Spinrad and Taylor
(1967AJ.....72S.320S 1967AJ.....72S.320S). Reddening values were computed using the
method of McClure and Racine (1969AJ.....74.1000M 1969AJ.....74.1000M).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 70 52 Table 1: Bright calibration stars
table4.dat 80 130 Table 4: Strong-cyanogen stars
--------------------------------------------------------------------------------
See also:
II/45 : Photometry of strong CN stars (Janes+ 1971)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
6- 9 I4 --- HR Bright Star (Harvard Revised) number (V/50)
10- 11 A2 --- m_HR Multiple star (last digit of companion number)
22- 26 F5.2 mag Vmag V-band magnitude in Johnson system
33- 37 F5.3 mag 45-48 C(45-48) color
44- 48 F5.3 mag 42-45 C(42-45) color
55- 59 F5.3 mag 41-42 C(41-42) color
66- 70 F5.3 mag m41-42 Unreddened Cm(41-42) color (G1)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
4- 9 I6 --- HD Star number in Henry Draper catalog (III/135)
22- 26 F5.2 mag Vmag V-band magnitude in Johnson system
28- 32 F5.2 mag B-V (B-V) color index in Johnson system
34- 38 F5.2 mag U-B (U-B) color index in Johnson system
40- 44 F5.2 mag E(B-V) Color excess
46- 50 F5.3 mag 45-48 C(45-48) color
52- 56 F5.3 mag 42-45 C(42-45) color
58- 62 F5.3 mag 41-42 C(41-42) color
64- 68 F5.3 mag m42-48 Unreddened C(42-48) color
70- 74 F5.3 mag m41-42 Unreddened Cm(41-42) color (G1)
76- 80 F5.2 mag dCm ? Cyanogen excess δCm(41-42) (G1)
--------------------------------------------------------------------------------
Global Notes:
Note (G1): "strong-cyanogen" stars have δCm(41-42)≥0.05mag, while
"normal stars" have |δCm(41-42)|≤0.03mag.
The cyanogen index is defined as:
Cm(41-42) = C(41-42) - 1.66[C(45-48) - 0.45C(42-45) - 0.792]
References:
McClure R.D. & Bergh S. van den 1968, Astron. J., 73, 313. Paper I.
McClure R.D. & Racine R. 1969, Astron. J., 74, 1000.
Schmitt J. 1967, thesis, U. Michigan, Ann Arbor, Michigan.
Spinrad H. & Taylor B. 1967, Astron. J., 72, 320.
History:
* the contents of tables 1 and 4 were originally keypunched at Institut
d'Astronomie de Lausanne (Switzerland) in October 1972,
* 13-May-1996: Short abstract added by Julie Anne Watko [SSDOO/ADC]
* 16-Jan-2017: description added at CDS (Francois Ochsenbein)
(End) Francois Ochsenbein 2017-Jan-16