J/MNRAS/475/1725 Astrometry of double stars measured in 2011 (Guerrero+, 2018)
Speckle interferometry at the OAN-SPM Mexico:
astrometry of double stars measured in 2011.
Guerrero C.A., Orlov V.G., Borges Fernandes M., Angeles F.
<Mon. Not. R. Astron. Soc., 475, 1725-1735 (2018)>
=2018MNRAS.475.1725G 2018MNRAS.475.1725G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Interferometry
Keywords: techniques: high angular resolution - techniques: interferometric -
binaries: close - binaries: visual
Abstract:
We present speckle interferometric measurements of binary stars
performed during 2011 February and April with the 1.5-m telescope and
during 2011 July and November with the 2.1-m telescope of the
Observatorio Astronomico Nacional, San Pedro Martir, Mexico, focusing
on objects from the Washington Double Star Catalog with separations
less than 1 arcsec. Among these objects, we have been interested in
performing a follow-up observation of new double stars discovered by
Hipparcos. For these observations, we developed a new detector, which
is a combination of CCD Watec 120N with a third generation image
intensifier. This image intensifier allows us to perform near-infrared
speckle interferometric observations for the first time. In this
paper, we report 761 astrometric measurements of 478 pairs, with
angular separations ranging from 0.09 to 2.61-arcsec. We found that
722 of our measured separations are smaller than 1-arcsec. We
estimated a mean error in separation of 16mas and 1.29° in
position angle. In order to overcome the usual 180° ambiguity
inherent to speckle measurements, we created a shift-and-add
reconstructed image of each source, to establish the true quadrant of
the secondary star. We confirmed 40 double stars discovered by
Hipparcos and found 4 field stars resolved as interferometric pairs
for the first time, with separations smaller than 0.60-arcsec.
Description:
We carried out our observations in 2011, during four observing runs at
the 1.5-m and 2.1-m telescopes of the OAN-SPM, Mexico. Specifically,
from February 11 to 16 and April 15 to 20, we observed at the 1.5-m
telescope, with moderate atmospheric conditions (seeing and
transparency). From July 15 to 19 and November 7 to 13, we observed at
the 2.1-m telescope, with excellent conditions for both runs. Our
sample selection consisted of stars with separations shorter than
1 arcsec, observable from the OAN-SPM, near the zenith. At the time
of our observations, most of our sample of visual binaries were not
observed since 20 yr ago or more. For the first two runs, most of our
sample stars were observed through standard V, R and I filters. Half
of the stars of the last two runs were observed through the R and I
filters and the others were observed using just the R filter. This led
to an apparent over population of stars resolved through the R
passband.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 101 396 Multi-band astrometry of known pairs observed
with the 1.5m telescope
table4.dat 101 365 Multi-band astrometry of known pairs observed
with the 2.1m telescope
refs.dat 106 60 References
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table?.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- WDS WDS name (HHMMs+DDMM, J2000)
12- 14 A3 --- n_WDS [*, HC] Note on WDS (1)
17- 28 A12 --- Name Discoverer designation
31- 36 F6.4 yr Epoch Epoch (Epoch-2011)
38- 42 F5.1 deg theta Position angle
44- 47 F4.1 deg e_theta rms uncertainty on theta
49- 52 F4.2 arcsec rho Sepration angle
54- 57 F4.2 arcsec e_rho rms uncertainty on rho
59- 64 F6.2 deg thetaO-C ? Observed minus computed Position angle
66- 70 F5.2 deg rhoO-C ? Observed minus computed Sepration angle
72- 97 A26 ---- Ref Reference, in refs.dat file
99-101 I3 nm lambda Wavelength (538, 630 or 894)
--------------------------------------------------------------------------------
Note (1): For star observed with both the 1.5m and the 2.1m telescopes,
notes as follows:
* = Position angle and separation largely different from previous
measurements
** = Position angle largely different from previous measurements
C = Ambiguous quadrant from reconstructed image. Quadrant adopted from
the latest measure in the WDS
H = Confirmed Hipparcos double star
--------------------------------------------------------------------------------
Byte-by-byte Description of file: refs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 26 A26 --- Ref Reference code
28-106 A79 --- Text Reference and comments
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 06-Apr-2021