Zobrazeno 1 - 10
of 70
pro vyhledávání: '"Lazorenko, P. F."'
We investigate how to quantitatively model the observed differential image motion (DIM) in relative astrometric observations. As a test bed we used differential astrometric observations from the FORS2 camera of the Very Large Telescope (VLT) obtained
Externí odkaz:
http://arxiv.org/abs/2408.05467
Autor:
Sahlmann, Johannes, Dupuy, Trent J., Burgasser, Adam J., Filippazzo, Joseph C., Martín, Eduardo L., Gagliuffi, Daniella C. Bardalez, Hsu, Dino Chih-Chun, Lazorenko, Petro F., Liu, Michael C.
The binary nature of the M8.5 dwarf DENIS J063001.4$-$184014AB (DE0630$-$18) was discovered with astrometric monitoring from the ground, which determined the unresolved photocentric orbit and the trigonometric parallax of the system. Here we present
Externí odkaz:
http://arxiv.org/abs/2011.08266
Autor:
Sahlmann, J., Burgasser, A. J., Gagliuffi, D. C. Bardalez, Lazorenko, P. F., Ségransan, D., Osorio, M. R. Zapatero, Blake, C. H., Gelino, C. R., Martín, E. L., Bouy, H.
Near-infrared spectroscopic surveys have uncovered a population of short-period, blended-light spectral binaries composed of low-mass stars and brown dwarfs. These systems are amenable to orbit determination and individual mass measurements via astro
Externí odkaz:
http://arxiv.org/abs/2004.14889
Autor:
Lazorenko, P. F., Sahlmann, J.
Publikováno v:
A&A 629, A113 (2019)
We present an investigation of the stability of the two chips in the FORS2 camera CCD mosaic on the basis of astrometric observations of stars in 20 sky fields, some of which were monitored for four to seven years. We detected a smooth relative shear
Externí odkaz:
http://arxiv.org/abs/1908.06056
Autor:
Lazorenko, P. F., Sahlmann, J.
Publikováno v:
A&A 618, A111 (2018)
The nearest known binary brown dwarf WISE J104915.57-531906.1AB (LUH 16) is a well-studied benchmark for our understanding of substellar objects. Previously published astrometry of LUH 16 obtained with FORS2 on the Very Large Telescope was affected b
Externí odkaz:
http://arxiv.org/abs/1808.07835
Autor:
Lazorenko, P. F., Sahlmann, J.
We compared positions of the Gaia first data release (DR1) secondary data set at its faint limit with CCD positions of stars in 20 fields observed with the VLT/FORS2 camera. The FORS2 position uncertainties are smaller than one milli-arcsecond (mas)
Externí odkaz:
http://arxiv.org/abs/1708.00795
Autor:
Sahlmann, J., Lazorenko, P. F., Ségransan, D., Astudillo-Defru, N., Bonfils, X., Delfosse, X., Forveille, T., Hagelberg, J., Curto, G. Lo, Pepe, F., Queloz, D., Udry, S., Zimmerman, N. T.
Publikováno v:
A&A 595, A77 (2016)
GJ676A is an M0 dwarf hosting both gas-giant and super-Earth-type planets discovered with radial-velocity measurements. Using FORS2/VLT, we obtained position measurements of the star in the plane of the sky that tightly constrain its astrometric refl
Externí odkaz:
http://arxiv.org/abs/1608.00918
Autor:
Sahlmann, J., Lazorenko, P. F., Bouy, H., Martín, E. L., Queloz, D., Ségransan, D., Osorio, M. R. Zapatero
We used the OSIRIS camera at the 10.4 m Gran Telescopio Canarias (GTC) to monitor the astrometric motion of the L4.5 dwarf 2M1821$+$14 over 17 months. The astrometric residuals of eleven epochs have a r.m.s. dispersion of 0.4 mas, which is larger tha
Externí odkaz:
http://arxiv.org/abs/1509.08718
Publikováno v:
Monthly Notices of the Royal Astronomical Society: Letters, 2015, Volume 453, Issue 1, p.L103-L107
We analyse FORS2/VLT $I$-band imaging data to monitor the motions of both components in the nearest known binary brown dwarf WISE J104915.57-531906.1AB (LUH16) over one year. The astrometry is dominated by parallax and proper motion, but with a preci
Externí odkaz:
http://arxiv.org/abs/1506.07994
Autor:
Sahlmann, J., Burgasser, A. J., Martín, E. L., Lazorenko, P. F., Gagliuffi, D. C. Bardalez, Mayor, M., Ségransan, D., Queloz, D., Udry, S.
Publikováno v:
A&A 579, A61 (2015)
Astrometric monitoring of the nearby early-L dwarf DE0823$-$49 has revealed a low-mass companion in a 248-day orbit that was announced in an earlier work. Here, we present new astrometric and spectroscopic observations that allow us to characterise t
Externí odkaz:
http://arxiv.org/abs/1505.07972