J/A+A/548/A16 Improved astrometry bor BE74 stars (Howarth, 2012) ================================================================================ Improved astrometry for the Bohannan & Epps catalogue. Howarth I.D. =2012A&A...548A..16H ================================================================================ ADC_Keywords: Positional data ; Cross identifications ; Stars, emission Keywords: astrometry - stars: emission-line - Magellanic Clouds Abstract: Accurate astrometry is required to reliably cross-match 20th-century catalogues against 21st-century surveys. The present work aims to provide such astrometry for the 625 entries of the Bohannan & Epps (BE74; 1974A&AS...18...47B) catalogue of H{alpha} emission-line stars. BE74 targets have been individually identified in digital images and, in most cases, unambiguously matched to entries in the UCAC4 (I/322) astrometric catalogue. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 165 647 *Astrometry for BE74 targets (corrected for small zero-point offsets as described in the text) table2.dat 80 116 Notes on individual objects table3.dat 65 202 Positional matches between measured BE74 co-ordinates and Skiff's results for HDE, Sk, and LHA 120-S targets, within a 5 arcsec radius -------------------------------------------------------------------------------- Note on table1.dat: Remaining data are representative measurements from UCAC4 (via CDS/Vizier, Cat. I/322). Where available, the UCAC4 astrometry is to be preferred. Note that additional information is available in UCAC4, including proper motions, which are generally negligible for the BE74 sources. -------------------------------------------------------------------------------- See also: I/322 : UCAC4 Catalogue (Zacharias+, 2012) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- [BE74] Sequential number 4 A1 --- m_[BE74] Multiplicity index on [BE74] (? when no positions measured) 8- 9 I2 h RAh ? Measured right ascension (J2000) 11- 12 I2 min RAm ? Measured right ascension (J2000) 14- 18 F5.2 s RAs ? Measured right ascension (J2000) 21 A1 --- DE- ? Measured declination sign (J2000) 22- 23 I2 deg DEd ? Measured declination (J2000) 25- 26 I2 arcmin DEm ? Measured declination (J2000) 28- 31 F4.1 arcsec DEs ? Measured declination (J2000) 37- 38 I2 h RA4h ? Matching UCAC4 right ascension (J2000) 40- 41 I2 min RA4m ? Matching UCAC4 right ascension (J2000) 43- 48 F6.3 s RA4s ? Matching UCAC4 right ascension (J2000) 50 A1 --- DE4- ? Matching UCAC4 declination sign (J2000) 51- 52 I2 deg DE4d ? Matching UCAC4 declination (J2000) 54- 55 I2 arcmin DE4m ? Matching UCAC4 declination (J2000) 57- 61 F5.2 arcsec DE4s ? Matching UCAC4 declination (J2000) 67- 76 A10 --- UCAC4 UCAC4 designation (ZZZ-NNNNNN) 80- 82 I3 mas ePos ? Total mean error on position at Ep=J2000 (3) 84- 89 F6.3 mag f.mag ? UCAC4 fit model magnitude (579-642nm) (4) 91 I1 --- of [0/9]? UCAC4 object classification flag (6) 93- 94 I2 --- db [0/36]? UCAC4 double star flag (7) 99-104 F6.3 mag Jmag ? 2MASS J magnitude 106-111 F6.3 mag Kmag ? 2MASS Ks magnitude 113-118 F6.3 mag Bmag ? B magnitude from APASS (12) 120-125 F6.3 mag Vmag ? V magnitude from APASS (12) 127-132 F6.3 mag rmag ? r magnitude from APASS (12) 134 I1 --- H [0/9]? Hipparcos/Tycho flag (15) 136-165 A30 --- Note Note -------------------------------------------------------------------------------- Note (3): taking into account the propagation of the proper motion error between the mean epoch and J2000. Note (4): systematic errors are expected to be below 0.1mag. Note (6): the object type flag is used to identify possible problems with a star and has the following meaning: 0 = good, clean star, no known problem 1 = near overexposed star 2 = possible streak object 3 = high proper motion (HPM) star 4 = actually use external HPM data instead of UCAC4 observed data (accuracy of positions varies between catalogs) 5 = poor proper motion solution, report only CCD epoch position 6 = substitute poor astrometric results by FK6/Hip/Tycho-2 data 7 = added supplement star (no CCD data) from FK6/Hip/Tycho-2 data, and 2 stars added from high proper motion surveys 8 = high proper motion solution in UCAC4, star not matched with PPMXL 9 = high proper motion solution in UCAC4, discrepant motion to PPMXL Note (7): The double star flag is used to indicate the type/quality of double star fit. It is a combination of 2 flags, dsf+dst: * dsf = double star flag, represents the overall classification: 0 = single star 10 = component #1 of "good" double star 20 = component #2 of "good" double star 30 = blended image * dst = double star type, derived from pixel data image profile fits (largest value of all images used for this star): 0 = no double star, not sufficient #pixels or elongation to even call double star fit subroutine 1 = elongated image but no more than 1 peak detected 2 = 2 separate peaks detected -> try double star fit 3 = secondary peak found on each side of primary 4 = case 1 after successful double fit (small separation, blended image) 5 = case 2 after successful double fit (most likely real double) 6 = case 3 after successful double fit (brighter secondary picked) Note (12): Data are from the AAVSO Photometric all-sky survey (APASS) DR6 plus single observation stars kindly provided by A.Henden. For bright stars the Bmag and Vmag columns contain the Hipparcos/Tycho Bt and Vt mags respectively, whenever there is no APASS B or V available and valid Bt or Vt mags were found. The errors flagged with "-" are formal errors estimated from the S/N, while the "normal" errors (flagged with ".") are from the official release data error estimates (at least 2 observations per star). Note (15): The FK6-Hipparcos-Tycho-source-flag has the following meaning: 0 = not a Hipparcos or Tycho star 1 = Hipparcos 1997 version main catalog (Cat I/239) 2 = Hipparcos double star annex 3 = Tycho-2 (Cat. I/259) 4 = Tycho annex 1 5 = Tycho annex 2 6 = FK6 position and proper motion (instead of Hipparcos data) 7 = Hippparcos 2007 solution position and proper motion (Cat. I/311) 8 = FK6, only PM substitution (not in UCAC4 data) 9 = Hipparcos 2007, only proper motion substituted (Cat. I/311) -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- [BE74] Sequential number 6- 80 A75 --- Notes Notes (1) -------------------------------------------------------------------------------- Note (1): acronyms used: * 'BE74' refers to Bohannan & Epps 1974A&AS...18...47B; * 'HW' to charts from the Hodge & Wright Atlas (Hodge & Wright 1967, The Large Magellanic Clous (Smithsonian Press, Washington D.C.); * 'RPs' to emission-line stars catalogued by Reid & Parker (2012MNRAS.425..355R, RP12) and * 'DSS2' to the red Digital Sky Survey images accessed through Aladin. * 'A','B' etc. refers to separate entries in Table 1. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- [BE74] BE74 number (use in conjunction with Table 1) 4 A1 --- n_[BE74] Multiplicity index on [BE74] 8- 16 A9 --- HDE HDE match 19- 22 F4.2 arcsec offHDE ? HDE match offset 27- 36 A10 --- Sk Sk match 38- 41 F4.2 arcsec offSk ? Sk match offset 46- 58 A13 --- LHA LHA12-S match 62- 65 F4.2 arcsec offLHA ? LHA12-S match offset -------------------------------------------------------------------------------- Acknowledgements: Ian Howarth, idh(at)star.ucl.ac.uk ================================================================================ (End) Francois Ochsenbein [CDS] 05-Oct-2012