We report CCD measurements of 33 visual double stars observed at the 1-meter coude reflector of the Observatorio de Llano del Hato located at Merida, Venezuela. We also present an algorithm to determine the stars' centroids for superimposed images as well as a brief comparison of accuracies attained by the algorithm and the program CENTER of the IRAF package.
We present measurements of visual double stars made by CCD imaging from 1996 to 1999. In the article, Table 1 contains the measurements of 51 binaries with known orbit. The residuals are discussed in the text. Table 2 presents new measurements for 555 binaries. Angular separation, position angle and magnitude difference are given.
The results of classical CCD observations for 371 double or multiple stars (450 pairs) obtained at both, Serbian Astronomical Station on the mountain of Vidojevica (ASV) and Bulgarian National Astronomical Observatory at Rozhen (NAOR) are presented. At ASV the observations were performed with the 0.6 m telescope in the first half of 2016 during 11 nights, and with the newly mounted 1.4 m telescope in the second half of 2016 during 16 nights. At NAOR, the observations were performed with the 2 m telescope during four nights. In this paper, we present 477 measurements (position angle and angular separation) for these 450 pairs. Among them there are 41 pairs with published orbital or linear elements and residuals are given for them. Some pairs have measurements for several epochs. Our observed pairs have angular separations in the interval from 1.60" to 190.30", with a mean angular separation of 14.87" and a median value of 4.34". Two new pairs and linear elements for four pairs which are calculated for the first time are also presented.
CCD measurements of multiple stars at NAOR and ASV
Short Name:
J/AJ/146/52
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using the 2m telescope of the Bulgarian National Astronomical Observatory at Rozhen, observations of 222 double or multiple stars were carried out during three nights in 2011. This is the sixth series of measurements of CCD frames of double and multiple stars obtained at Rozhen. Also in 2011, using the 0.6m telescope of the Serbian Astronomical Station on the mountain of Vidojevica, observations of 208 double or multiple stars were carried out during six nights. This is the first series of measurements of CCD frames of double and multiple stars obtained at this station. In this paper, we present the results for the position angle and angular separation for 337 pairs and residuals for 72 pairs with published orbital elements or linear solutions. These observations have angular separations in the range from 1.37'' to 172.81'', with a median angular separation of 7.66''. We also present the recalculated linear solutions for four pairs and one linear solution that has been calculated for the first time.
- Observatory and telescope: Sylvester Robotic Observatory (SRO): 33cm f/4.5 Newtonian on Paramount GT-1100s mount - Detector: SRO: SBIG ST7e, 1.24 pixels, 15.8x10.5 FOV, cooled -10<T<-30{deg}C - Method of data reduction: Aperture photometry using MIRA, by Axiom Research - Method of minimum determination: Digital tracing paper method, bisection of chords, curve fitting, and (occasionally) Kwee and van Woerden (1956BAN....12..327K)
This paper give positions of Martian satellites system from CCD observations obtained at the Cassegrain focus of a 1.6m reflector for the years 1995 and 2003.
229 CCD positions of Nereid taken between 1993 and 1998 are presented. Many of the observations were taken near the periapsis. Considering also the other published positions we have a good distribution of the observations on the eccentric orbit of the satellite. Using a numeric integration method we fitted all these observations in order to determine one state vector for the orbit. The observed minus calculated standard deviation for all observations is 0.23", and for our observations it is 0.16".
In 1998 and 1999, we started observations of the 9th satellite of Saturn. We made 163 observations using the 120cm-telescope of Observatoire de Haute-Provence, France. We used the USNO A2 catalogue (Cat. <I/252>) of stars for the astrometric reduction. With the help of observations of optical counterparts of ICRF sources, a zonal correction to the USNO A2.0 catalogue was computed and applied to the Phoebe positions. A comparison to the most recent theories was made.
The astrometric positions of seven saturnian satellites are presented. Positions were derived from more then 5000 CCD frames taken with 26-inch Zeiss refractor at Pulkovo from Jan 2008 to may 2009. Astrometric reduction algorithm is based on Turner's method with using UCAC2 catalog as reference one. Observed positions were compared with theoretical ones from TASS 1.7 (Viennel & Duriez, 1995A&A...297..588V). The accuracy is about 0.05 arcsec. Also positions of Saturn were obtained from observations of satellites 2-6.
We present the results of 3632 astrometric CCD-measurements of 314 visual double stars performed with the 26-inch refractor of the Pulkovo observatory in 2003-2007. Angular separations (rho) and position angles (theta) are provided. Mean values of standard errors are 0.009" in rho and 0.40(deg)/rho in theta, where rho is the separation in arcseconds.