J/PAZh/44/124 Binary systems among nearby dwarfs searching (Khovritchev+, 2018)
Searching for binary systems among nearby dwarfs based on Pulkovo
observations and SDSS data.
Khovritchev M.Yu., Apetyan A.A., Roshchina E.A., Izmailov I.S.,
Bikulova D.A., Ershova A.P., Balyaev I.A., Kulikova A.M., Petjur V.V.,
Shumilov A.A., Oskina K.I., L.A. Maksimova
<Pis'ma Astron. Zh. 44, 124-139 (2018)>
=2018AstL...44..103K 2018AstL...44..103K
=2018PAZh...44..124K 2018PAZh...44..124K (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, dwarfs ; Stars, nearby
Keywords: Galactic solar neighborhoods - stars with large proper motions -
shapelet formalism - visual double stars - Gaia DR1
Abstract:
Our goal is to find previously unknown binary systems among low-mass
dwarfs in the solar neighborhood and to test the search technique. The
basic ideas are to reveal the images of stars with significant
ellipticities and/or asymmetries compared to the background stars on
CCD frames and to subsequently determine the spatial parameters of the
binary system and the magnitude difference between its components. For
its realization we have developed a method based on an image shapelet
decomposition. All of the comparatively faint stars with large proper
motions (Vmag>13m, µ>300mas/yr) for which the 'duplicate source'
flag in the Gaia DR1 catalogue is equal to one have been included in
the list of objects for our study. As a result, we have selected 702
stars. To verify our results, we have performed additional
observations of 65 stars from this list with the Pulkovo 1-m 'Saturn'
telescope (2016-2017). We have revealed a total of 138 binary
candidates (nine of them from the `Saturn' telescope and SDSS data).
Six program stars are known binaries. The images of the primaries of
the comparatively wide pairs WDS 14519+5147, WDS 11371+6022, and WDS
15404+2500 are shown to be resolved into components; therefore, we can
talk about the detection of triple systems. The angular separation
ρ, position angle, and component magnitude difference Δm
have been estimated for almost all of the revealed binary systems. For
most stars 1.5''<ρ<2.5'', while Δm<1.5m.
Description:
All results are collected in three tables: saturn1m-bc.dat,
saturn1m-sdss-bc.dat and sdss-bc.dat. They have the same byte-by-byte
description. The tables contain the estimates of spatial parameters of
binaries (rho and d_m), relative ellipticity and asymmetry index. In
addition, the positions, proper motions, photometric magnitudes,
parallaxes and metallicities are presented. All stars listed in these
tables are binary candidates.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sasdssbc.dat 294 9 "Saturn" telescope and SDSS binary candidates
sat-bc.dat 294 11 Pulkovo 1-m "Saturn" telescope binary candidates
sdss-bc.dat 294 133 SDSS binary candidates
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2014)
I/298 : LSPM-North Catalog (Lepine+ 2005)
I/333 : URAT Parallax Catalog (UPC) (Finch+, 2016)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
Byte-by-byte Description of file: sasdssbc.dat sat-bc.dat sdss-bc.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- LSPM LSPM-north (I/298/lspm_n) Catalogue ID
14- 21 F8.3 yr Epoch Epoch of observations
23- 24 I2 h RAh Right Ascension (J2000)
25 A1 --- --- [:]
26- 27 I2 min RAm Right Ascension (J2000)
28 A1 --- --- [:]
29- 35 F7.4 s RAs Right Ascension (J2000)
37 A1 --- DE- Declination sign (J2000)
38- 39 I2 deg DEd Declination (J2000)
40 A1 --- --- [:]
41- 42 I2 arcmin DEm Declination (J2000)
43 A1 --- --- [:]
44- 50 F7.4 arcsec DEs Declination (J2000)
53- 58 F6.3 mag Vmagest LSPM estimated V-magnitude
61- 66 F6.3 arcsec/yr pmRA Proper motion in RA (I/298/lspm_n)
69- 74 F6.3 arcsec/yr pmDE Proper motion in DE (I/298/lspm_n)
77- 81 F5.3 arcsec rho ? Angular separation
84- 88 F5.3 arcsec e_rho ? Standard error of rho
91- 95 F5.1 deg theta ? Positional Angle
99-102 F4.1 deg e_theta ? Standard error of theta
105-109 F5.3 mag dm ? Magnitude difference (1)
112-116 F5.3 mag e_dm ? Stadard error of dm
118-121 F4.1 --- Se (et-eb)/sigma_e (2)
123 A1 --- Femax [ugrizBCVR] Filter with maximum (Se)
125-128 F4.1 --- SA (At-Ab)/sigma_A (3)
130 A1 --- FAmax [ugrizBCV] Filter with maximum S_A
132 I1 --- f [0/1] Flag for Gaia DR1 (4)
134-143 A10 --- WDS ID of star in WDS catalogue (B/wds/wds)
145-150 F6.3 mag umag ? u magnitude from SDSS (V/139)
152-157 F6.3 mag gmag ? g magnitude from SDSS
159-164 F6.3 mag rmag ? r magnitude from SDSS
166-171 F6.3 mag imag ? i magnitude from SDSS
173-178 F6.3 mag zmag ? z magnitude from SDSS
181-185 F5.3 mag e_umag ? Error of u magnitude from SDSS
188-192 F5.3 mag e_gmag ? Error of g magnitude from SDSS
195-199 F5.3 mag e_rmag ? Error of r magnitude from SDSS
202-206 F5.3 mag e_imag ? Error of i magnitude from SDSS
209-213 F5.3 mag e_zmag ? Error of z magnitude from SDSS
215-220 F6.3 mag Jmag J magnitude from 2MASS (II/246)
222-227 F6.3 mag Hmag H magnitude from 2MASS
229-234 F6.3 mag Ksmag Ks magnitude from 2MASS
237-241 F5.3 mag e_Jmag Error of J magnitude from 2MASS
244-248 F5.3 mag e_Hmag Error of H magnitude from 2MASS
251-255 F5.3 mag e_Ksmag Error of Ks magnitude from 2MASS
259-262 F4.1 mas UPCplx ? UPC trigonometric plx (I/333/upc)
265-268 F4.1 mas e_UPCplx ? Standard error of UPC plx
271-274 F4.1 mas MEplx ? MEarth trigonometric parallax (5)
277-279 F3.1 mas e_MEplx ? MEarth parallax standard error
281-284 A4 --- SpType Spectral type
289-293 F5.3 [-] [Fe/H]Photo ? Metallicity from MEarth (5)
294 A1 --- --- [|]
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Note (1): Magnitude difference is calculated for filter with maximum value of
ellipticity Fe_max.
Note (2): sigma_e is a mutual standard error of the ellipticity.
sigma_e = sqrt{et2+eb2}, where et is ellipticity of target,
and eb is ellipticity of background stars.
If sigma_e≥3, the star is considered as a binary candidate.
Note (3): It is similar as (2) for asymmetry index.
Note (4): f=1 if another Gaia-DR1 star is within the 32x32 pixel area
of the target star. Otherwise, f=0.
Note (5): MEarth trigonometric parallaxes and metallicities taken from the
photometric relation presented in Dittmann et al. (2016ApJ...818..153D 2016ApJ...818..153D).
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Acknowledgements:
Maxim Khovritchev, deimos(at)gaoran.ru
(End) M. Khovritchev [Pulkovo Obs., Russia], P. Vannier [CDS] 06-Mar-2018