J/MNRAS/407/681 Proper motions of FBS blue stellar objects (Mickaelian+, 2010)
Proper motions and natures of First Byurakan Survey blue stellar objects.
Mickaelian A.M., Sinamyan P.K.
<Mon. Not. R. Astron. Soc., 407, 681-690 (2010)>
=2010MNRAS.407..681M 2010MNRAS.407..681M
ADC_Keywords: Blue objects ; Proper motions
Keywords: methods: statistical - catalogues - surveys - astrometry -
proper motions - stars: white dwarfs
Abstract:
A new method for combined calculations of proper motions (PMs) based
on accurate measurements of POSS1 and POSS2 epoch plates is given. The
positional accuracy of various surveys and catalogues is estimated,
and statistical weights for each of them are established. To achieve
the best positions, weighted averaging of direct measurements on
DSS1/DSS2, and data from APM, MAPS, USNO-A2.0, USNO-B1.0 and GSC 2.3.2
catalogues were used. The rms accuracy of positions achieved for POSS1
is 119mas in each coordinate and 168 mas total and for POSS2 is 69mas
in each coordinate and 98mas total.
Using these accurate positions and the large separation in years
between POSS1 and POSS2, we have calculated the best possible proper
motions: 3.9mas/yr in each coordinate and 5.5mas/yr total. We have
worked out methods to control and exclude accidental errors that
appear in any survey. We have compared and combined our PM with those
given in USNO-B1.0, SDSS DR7, and Tycho-2 catalogs and obtained even
better results: 3.0mas/yr in each coordinate and 4.2mas/yr total PM.
This approach has been applied to the First Byurakan Survey blue
stellar objects containing a significant number of white dwarfs
and subdwarfs. Altogether 640 objects have been revealed with
PM≥10mas/yr, the detection limit for this method; and an electronic
table of these objects is given. For more confident proper motions,
we adopt the limit 20mas/yr (333 objects). Adopting 50km/s as an upper
limit for tangential velocities, we have calculated maximum distances
and absolute magnitudes and estimated luminosity types for these
objects and obtained 185 probable white dwarfs (M>8mag), 69 possible
white dwarfs (6mag<M<8mag), and 42 candidate sd/WDs (3mag<M<6mag).
Given that we have re-discovered 141 genuine white dwarfs among the
classified objects, the success rate of discovery of white dwarfs is
estimated as 83% and 38% for our probable and possible white dwarfs,
respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 141 640 FBS blue stellar objects having µ≥10mas/yr
table4.dat 54 297 FBS blue stellar objects having µ≥20mas/yr
and absolute magnitudes fainter than 3mag
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See also:
I/267 : The APM-North Catalogue (McMahon+, 2000)
I/252 : The USNO-A2.0 Catalogue (Monet+ 1998)
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
I/305 : The Guide Star Catalog, Version 2.3.2 (GSC2.3) (STScI, 2006)
II/223 : First Byurakan Survey (FBS), 2nd Program (Abrahamian+, 1990-96)
J/A+A/426/367 : FBS blue stellar objects DSS1/DSS2 astrometry (Mickaelian 2004)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq FBS sequential number (FSB B NNNN, Cat. II/223)
6- 14 A9 --- FBS FBS name (HHMM+DDMA)
16- 27 F12.8 deg RA1deg POSS1 best J2000 position, at epoch "Epoch1"
29- 39 F11.8 deg DE1deg POSS1 best J2000 position, at epoch "Epoch1"
41- 44 I4 mas e_RA1deg rms uncertainty on RA1deg
46- 49 I4 mas e_DE1deg rms uncertainty on DE1deg
51- 58 F8.3 yr Epoch1 POSS1 observation date
60- 71 F12.8 deg RA2deg POSS2 best J2000 position, at epoch "Epoch2"
73- 83 F11.8 deg DE2deg POSS2 best J2000 position, at epoch "Epoch2"
85- 87 I3 mas e_RA2deg rms uncertainty on RA2deg
89- 91 I3 mas e_DE2deg rms uncertainty on DE2deg
93-100 F8.3 yr Epoch2 POSS2 observation date
102-105 F4.1 yr Diff Separation in years between POSS1 and POSS2
107-112 F6.1 mas/yr pmRA Proper motion along RA (computed along small
circle with cosDE term)
114-119 F6.1 mas/yr pmDE Proper motion along DE
121-124 F4.1 mas/yr e_pmRA rms uncertainty on pmRA
126-129 F4.1 mas/yr e_pmDE rms uncertainty on pmDE
131-135 F5.1 mag/yr pmt Total proper motion
137-141 F5.1 deg pmPA Position angle of the proper motion
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq FBS sequential number (FSB B NNNN, Cat. II/223)
6- 14 A9 --- FBS FBS name (HHMM+DDMA)
16- 20 F5.2 mag Omag MAPS/USNO-B1 O magnitude
22- 26 F5.2 mag O-E MAPS/USNO-B1 O-E colour index
28- 32 F5.1 mas/yr pm Total proper motion calculated by weighted
averaging of our, USNO-B1.0, Tycho-2 and SDSS data
34- 36 I3 pc rmax Maximum distance estimated adopting a maximum
tangential velocity vt=50km/s
38- 42 F5.2 mag OMAG MAPS/USNO combined absolute O magnitude
44- 48 A5 --- LumT Luminosity type estimation according to our
adopted scheme (WD, WD:, or sd/WD)
50- 54 A5 --- SpT Genuine classification based on SIMBAD/MCS/SDSS
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History:
From electronic version of the journal and A. Mickaelian
[Byurakan Astrophysical Observatory]
(End) Patricia Vannier [CDS] 31-Jan-2011