J/MNRAS/341/805 UBVI CCD photometry of Cep OB3b (Pozzo+, 2003)
The discovery of low-mass pre-main-sequence stars in Cepheus OB3b. Pozzo M., Naylor T., Jeffries R.D., Drew J.E. <Mon. Not. R. Astron. Soc., 341, 805-822 (2003)> =2003MNRAS.341..805P
ADC_Keywords: Clusters, open ; Photometry, CCD ; Photometry, UBVRI Keywords: accretion, accretion discs - techniques: radial velocities - stars: formation - stars: late-type - stars: pre-main-sequence - open clusters and associations: individual: Cepheus OB3 Abstract: We report the discovery of a low-mass pre-main-sequence (PMS) stellar population in the younger subgroup of the Cepheus OB3 association, Cep OB3b, using UBVI CCD photometry and follow-up spectroscopy. The optical survey covers approximately 1300arcmin2 on the sky and gives a global photometric and astrometric catalogue for more than 7000 objects. The location of a PMS population is well defined in a V versus (V-I) colour-magnitude diagram. Description: The UBVI CCD images were taken on the nights of 1997 August 10/11 and 11/12, with the 2.5-m Isaac Newton Telescope (INT), La Palma, Canary Islands, Spain, equipped with the Wide Field Camera (WFC) and an array of four Loral CCDs. Data were taken using filters U (RGO), B (Harris), V (Harris) and I (RGO INT-WFC). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file catalog.dat 119 13657 Photometric catalogue flags.dat 84 18 Flags
Byte-by-byte Description of file: catalog.dat
Bytes Format Units Label Explanations
1- 4 F4.2 --- Field Field and CCD number (1) 6- 9 I4 --- Star Star number in the field 12- 13 I2 h RAh Right ascension (J2000.0) 15- 16 I2 min RAm Right ascension (J2000.0) 18- 23 F6.3 s RAs [0/60] Right ascension (J2000.0) 25 A1 --- DE- Declination sign (J2000.0) 26- 27 I2 deg DEd Declination (J2000.0) 29- 30 I2 arcmin DEm Declination (J2000.0) 32- 36 F5.2 arcsec DEs [0/60] Declination (J2000.0) 38- 45 F8.3 pix Xpos X position in the CCD image 47- 54 F8.3 pix Ypos Y position in the CCD image 56- 61 F6.3 mag Vmag ? V magnitude 62 A1 --- n_Vmag [I] I for +Inf 64- 68 F5.3 mag e_Vmag rms uncertainty on Vmag 70- 71 A2 --- f_Vmag Flag on Vmag, in flags. dat file 73- 78 F6.3 mag B-V B-V colour index 80- 84 F5.3 mag e_B-V rms uncertainty on B-V 86- 87 A2 --- f_B-V Flag on B-V colour, in flags.dat file 89- 94 F6.3 mag V-I V-I colour index 96-100 F5.3 mag e_V-I rms uncertainty on V-I 102-103 A2 --- f_V-I Flag on V-I colour, in flags.dat file 105-110 F6.3 mag U-B U-B colour index 112-116 F5.3 mag e_U-B rms uncertainty on U-B 118-119 A2 --- f_U-B Flag on U-B colour, in flags.dat file
Note (1): The number before the decimal place is the field number, the one after is the CCD number.
Byte-by-byte Description of file: flags.dat
Bytes Format Units Label Explanations
1 A1 --- Flag Flag code (1) 3- 49 A47 --- Explain Flag meaning 51- 75 A25 --- Algorithm Algorithm used 77- 82 A6 --- Type Type (Strong or Weak) 84 I1 --- Fno ? Flag number for the older versions of the software
Note (1): If a star is flagged as having negative counts (M), the magnitude is replaced with the uncertainty in flux converted into magnitudes. Thus magnitudes for objects flagged M should be treated as bright (i.e. lower) limits. It also means that colours which are quoted for these objects are limits. For example a flag of MO in the B-V colour, means that the B magnitude is a lower limit, so B-V is a lower limit. The uncertainty becomes meaningless, unless you want the description for real aficionados...
History: Copied at http://www.astro.ex.ac.uk/people/timn/Catalogues/PNJD2003/
(End) Patricia Vannier [CDS] 05-Apr-2007
|The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line|