J/AJ/130/2866 Differential astrometry of δ Equulei (Muterspaugh+, 2005)
PHASES high-precision differential astrometry of δ Equulei.
Muterspaugh M.W., Lane B.F., Konacki M., Burke B.F., Colavita M.M.,
Kulkarni S.R., Shao M.
<Astron. J., 130, 2866-2875 (2005)>
=2005AJ....130.2866M 2005AJ....130.2866M
ADC_Keywords: Stars, double and multiple ; Positional data ; Radial velocities
Keywords: astrometry - binaries: close - binaries: visual - stars: distances -
stars: individual (δ Equulei) - techniques: interferometric
Abstract:
Delta Equulei is among the most well-studied nearby binary star
systems. Results of its observation have been applied to a wide range
of fundamental studies of binary systems and stellar astrophysics. It
is widely used to calibrate and constrain theoretical models of the
physics of stars. We report 27 high-precision differential astrometry
measurements of δ Equ from the Palomar High-precision
Astrometric Search for Exoplanet Systems (PHASES).
Description:
Delta Equ was observed with Palomar Testbed Interferometer (PTI) on 27
nights in 2003-2004.
Objects:
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RA (2000) DE Designation(s)
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21 14 28.8 +10 00 25 δ Equulei = HD 202275
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 76 27 PHASES data for δ Equulei
table2.dat 77 46 Previous differential astrometry data with
published uncertainties for δ Equulei
table3.dat 64 66 Previous visual astrometry without uncertainties
table4.dat 74 58 Previous interferometric astrometry without
uncertainties
table5.dat 18 17 Lick observatory radial velocities
table6.dat 32 78 DAO radial velocities
table7.dat 33 35 CORAVEL radial velocities
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 F11.5 d MJD Modified Julian Date of observation
13- 19 F7.4 mas oRA Right Ascension offset (1)
21- 28 F8.4 mas oDE Declination offset (1)
30- 34 F5.1 uarcsec e_Min The 1σ error in the Minor axis (1)(2)
36- 41 F6.1 uarcsec e_Maj The 1σ error in the Major axis (1)(2)
43- 48 F6.2 deg phi Angle between the major axis of the
uncertainty ellipse and the RA axis (1)(3)
50- 55 F6.1 uarcsec e_oRA The 1σ error in oRA (1)(2)
57- 62 F6.1 uarcsec e_oDE The 1σ error in oDE (1)(2)
64- 71 F8.5 --- corr The ratio of σRA,Dec2 to
(σRA*σDec); covariance
73- 76 I4 --- NScan Number of scans during a given night (4)
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Note (1): All quantities are in the ICRS 2000.0 reference frame.
Note (2): The uncertainty values presented in these data have all been scaled
by a factor of 3.8 over the formal (internal) uncertainties within
each given night.
Note (3): Measured from increasing differential right ascension through
increasing differential declination (the position angle of the
uncertainty ellipse's orientation is 90-phi).
Note (4): The quadrant was chosen such that the larger fringe contrast is
designated the primary (contrast is a combination of source
luminosity and interferometric visibility).
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 F9.4 yr Obs.Date Date of the observation, in decimal years
11- 13 I3 mas rho Separation
15- 20 F6.2 deg theta Position angle
22- 26 F5.2 mas e_rho The 1σ uncertainty in rho (1)
28- 32 F5.2 deg e_theta The 1σ uncertainty in theta (1)
34- 77 A44 --- Ref Reference
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Note (1): rho uncertainties have been increased by a factor of 1.71 and those
for theta by a factor of 2.38. In many cases theta has been changed
by 180 degrees from the value appearing in the original works.
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Byte-by-byte Description of file: table[34].dat
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Bytes Format Units Label Explanations
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1- 9 F9.4 yr Obs.Date Date of the observation, in decimal year
11- 13 I3 mas rho Separation (1)
15- 19 F5.1 deg theta Position angle (1)
21- 74 A54 --- Ref Reference
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Note (1): The uncertainties presented in this table were determined by the
scatter in the data. In many cases theta has been changed by
180 degrees from the value appearing in the original works.
For the values in table3, all uncertainties were taken to be
σρ=37.2mas and σθ=3.53degrees.
For the values in table4, all uncertainties were taken to be
σρ=5.92mas and σθ=1.59degrees.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 7 F7.1 d MJD Modified Julian Date of Observation
9- 12 F4.1 km/s RV1 Primary radial velocity (1)
14- 18 F5.1 km/s RV2 Secondary radial velocity (1)
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Note (1): Lick Observatory data from Dworetsky et al. (1971PASP...83..207D 1971PASP...83..207D) and
Popper and Dworetsky (1978PASP...90...71P 1978PASP...90...71P) used for the combined
orbital fit in this paper. A model fit of this data set separately
was used to determine the uncertainties used. Note that the original
work switched the designations of the primary and secondary
components; this has been corrected here for combination with other
data sets. For the values in this table, all uncertainties were taken
to be 0.35 km/s, except for the point on JD-2400000.5=40428.3 for
which the uncertainties were 0.70km/s.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 8 F8.3 yr Obs.Date Date od the observation, in decimal year
10- 15 F6.2 km/s RV1 Primary radial velocity (1)
17- 20 F4.2 km/s e_RV1 The 1σ error in RV1 (1)
22- 27 F6.2 km/s RV2 Secondary radial velocity (1)
29- 32 F4.2 km/s e_RV2 The 1σ error in RV2 (1)
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Note (1): Dominion Astrophysical Observatory data from Hans et al.
(1979ApJ...229.1001H 1979ApJ...229.1001H) used for the combined orbital fit in this paper.
A model fit of this data set separately was used to determine the
uncertainties used.
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 d MJD Modified Julian date
11- 16 F6.2 km/s RV1 Primary radial velocity (1)
18- 21 F4.2 km/s e_RV1 The 1σ error in RV1 (1)
23- 28 F6.2 km/s RV2 Secondary radial velocity (1)
30- 33 F4.2 km/s e_RV2 The 1σ error in RV2 (1)
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Note (1): CORAVEL data from Duquennoy and Mayor (1988A&A...195..129D 1988A&A...195..129D) used for
the combined orbital fit in this paper. The uncertainties have been
reweighted by a factor of 1.527 from the original work, in order that
they might be combined with other data sets for a simultaneous fit.
Note that the original work switched the designations of the primary
and secondary components; this has been corrected here for combination
with other data sets.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 21-Jul-2006