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J/AJ/126/3017    Distances of Cataclysmic variables    (Thorstensen, 2003)

Parallaxes and distance estimates for 14 cataclysmic variable stars. Thorstensen J.R. <Astron. J., 126, 3017-3029 (2003)> =2003AJ....126.3017T
ADC_Keywords: Stars, variable ; Parallaxes, trigonometric ; Stars, distances Keywords: binaries: general - novae, cataclysmic variables - stars: distances - stars: variables: other Abstract: The 2.4m Hiltner Telescope at MDM Observatory was used in an attempt to measure trigonometric parallaxes for 14 cataclysmic variable stars. Techniques are described in detail. In the best cases the parallax uncertainties are below 1mas, and significant parallaxes are found for most of the program stars. A Bayesian method that combines the parallaxes together with proper motions and absolute magnitude constraints is developed and used to derive distance estimates and confidence intervals. The most precise distance derived here is for WZ Sge, for which is found to be 43.3+1.6-1.5pc. Six Luyten Half-Second stars with previous precise parallax measurements were remeasured to test the techniques, and good agreement was found. Description: All the observations are from the f/7.5 focus of the 2.4m Hiltner Telescope at MDM Observatory on Kitt Peak, Arizona. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 93 1203 Positions, Magnitudes, Parallaxes, and Proper Motions table4.dat 134 14 Parallaxes, proper motions, and distances table5.dat 50 9 Measured and theoretical absolute magnitudes
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 17 A17 --- Field Cataclysmic Variable Star name, as field designation (1) 19 A1 --- f_Field [*] Indicates the program star 21- 22 I2 h RAh Hour of Right Ascension (J2000) (2) 24- 25 I2 min RAm Minute of Right Ascension (J2000) (2) 27- 31 F5.2 s RAs Second of Right Ascension (J2000) (2) 33 A1 --- DE- Sign of the Declination (J2000) (2) 34- 35 I2 deg DEd Degree of Declination (J2000) (2) 37- 38 I2 arcmin DEm Arcminute of Declination (J2000) (2) 40- 43 F4.1 arcsec DEs Arcsecond of Declination (J2000) (2) 45 I1 --- Weight [0/1] Reference star indicator (3) 47- 49 I3 mas sigma Scatter around the best astrometric fit (4) 51- 55 F5.2 mag Vmag The V band magnitude (5) 57- 61 F5.2 mag V-I The (V-I) color (5) 63- 68 F6.1 mas plx Fitted parallax 70- 73 F4.1 mas e_plx Error in plx 75- 80 F6.1 mas/yr pmX X (RA) tangent-plane direction proper motion 82- 87 F6.1 mas/yr pmY Y (DE) tangent-plane direction proper motion 89- 92 F4.1 mas/yr sigpm Uncertainty in proper motion (per coordinate)
Note (1): The fourth star listed in the LHS 1889 field proved to be a hitherto unknown L3.5 dwarf. Note (2): The celestial coordinates are from mean CCD images and are referred to the USNO A2.0 (Cat. I/252), which is in turn aligned with the ICRS; the epochs of the images used are typically around 1998. Coordinates should be accurate to ∼0.3" external and somewhat better than this internally. Note (3): Reference star indicator: 0 = not used as a reference star; 1 = used as a reference star. Note (4): In a few cases these are very large (e.g. close pairs which were intermittently resolved). Note (5): Typical external uncertainties of 0.05mag and internal consistency somewhat better than that.
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Star Star name 11- 14 F4.1 mas plx Relative parallax 16- 18 F3.1 mas e_plx rms uncertainty on plx derived from the goodness of fit 20- 22 F3.1 mas e_plx2 rm uncertainty on plx derived from the scatter of the reference stars 24- 27 F4.1 mag PLX Absolute parallax 29- 31 F3.1 mag e_PLX rms uncertainty on PLX 33- 37 F5.1 pc dLK ? Most probable value of the distance based on absolute parallax and a Lutz-Kelker correction 39- 44 F6.1 pc d(pi+mu) Bayesian distance estimate considering the parallax and proper motion prior only 46- 51 F6.1 pc E_d(pi+mu) Error on d(pi+mu) (upper limit) 53- 57 F5.1 pc e_d(pi+mu) Error on d(pi+mu) (lower limit) 59- 64 F6.1 mas/yr pmRA Proper motion in right ascension 66- 70 F5.1 mas/yr pmDE Proper motion in declination 72- 74 F3.1 mas/yr e_pmRA rms uncertainty on pmRA and pm DE 76- 80 F5.2 mag mag ? Apparent magnitude 82- 85 F4.1 mag MAG ? Assumed absolute magnitude 87- 89 F3.1 mag e_MAG ? 1sigma combined uncertainty for mag and MAG 91- 93 F3.1 mag m-M ? Distance modulus 95- 97 F3.1 mag e_m-M ? rms uncertainty on m-M 99-103 F5.1 1/mas 1/piabs Inverse of absolute parallax 105-109 F5.1 1/mas E_1/piabs Error on 1/piabs (upper limit) 111-115 F5.1 1/mas e_1/piabs Error on 1/piabs (lower limit) 118-122 F5.1 pc d(pi+mu+m-M) Distance, taking account parallax, proper motion and distance modulus as prior 124-128 F5.1 pc E_d(pi+mu+m-M) Error on distance (upper limit) 130-134 F5.1 pc e_d(pi+mu+m-M) Error on distance (lower limit)
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Star Star name 11- 14 F4.2 h Porb Orbital period 16- 17 I2 deg Incl Inclination 19- 20 I2 deg e_Incl rms uncertainty on Incl 22- 25 F4.1 mag Vmax Maximum V magnitude 27- 29 F3.1 mag VMAG Predicted maximum absolute V magnitude 31- 33 F3.1 mag E_VMAG Error on VMAG (upper limit) 35- 37 F3.1 mag e_VMAG Error on VMAG (lower limit) 39- 41 F3.1 mag VMAGm Measured maximum absolute V magnitude 43- 45 F3.1 mag E_VMAGm Error on VMAGm (upper limit) 47- 49 F3.1 mag e_VMAGm Error on VMAGm (lower limit)
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 12-Jan-2004
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

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