Discovery, Observational Data and the Orbit of the Amor Group Asteroid 2010 BT3

2012 ◽  
Vol 21 (3) ◽  
Author(s):  
K. Černis ◽  
J. Zdanavičius ◽  
I. Wlodarczyk ◽  
E. Stonkutė
Keyword(s):  
Observational Data ◽  
Absolute Magnitude ◽  
Apparent Brightness ◽  
Photometric Observations ◽  
The Absolute ◽  
Near Earth Objects

AbstractA project devoted to astrometric and photometric observations of asteroids at the Molėtai Observatory is described. One of its most important results is the discovery of the asteroid 2010 BT3 belonging to the Amor group of the near-Earth objects. The results of astrometric and photometric observations of the asteroid are presented. The brightness variations of the asteroid are found to be about 0.2 mag in R. The orbit of the asteroid was computed from 96 observations. This orbit, combined with the apparent brightness, gives the absolute magnitude 21.34 mag and the diameter between 160 m and 360 m, taking albedos of S-type and C-type asteroids, respectively.

scholarly journals Discovery, Observational Data and the Orbit of the Transneptunian Object (420356) Praamžius

2016 ◽  
Vol 25 (2) ◽  
Author(s):  
K. Černis ◽  
R. P. Boyle ◽  
I. Wlodarczyk
Keyword(s):  
Observational Data ◽  
Absolute Magnitude ◽  
Optical Observations ◽  
Apparent Brightness ◽  
Photometric Observations ◽  
The Absolute

AbstractA project for astrometric and photometric observations of asteroids with the VATT telescope on Mt. Graham is described. One of the most important results is the discovery of the Transneptunian object (420356) Praamžius. We computed its orbit applying 198 optical observations from 2003 February 1 to 2016 January 30. We also followed its orbit searching for minimal distances to Neptune between the years 17 000 and −13 000. Combined with the apparent brightness, the orbit gives the absolute magnitude

Discovery, Observational Data and the Orbit of the Centaur Asteroid 2012 DS85

2012 ◽  
Vol 21 (4) ◽  
Author(s):  
K. Černis ◽  
R. P. Boyle ◽  
V. Laugalys ◽  
I. Wlodarczyk
Keyword(s):  
Observational Data ◽  
Absolute Magnitude ◽  
Photometric Data ◽  
Apparent Brightness ◽  
Photometric Observations

AbstractA project for astrometric and photometric observations of asteroids at Mt. Graham Observatory with the VATT telescope is described. One of the most important results is a discovery of the Centaur 2012 DS85. Astrometric and photometric data on the asteroid are presented. The orbit of the asteroid was computed from 67 observations. Combined with its apparent brightness, the orbit gives an absolute magnitude of 9.43. Using a typical albedo value of 0.08 for Centaurs and TNOs (Moullet et al. 2011), we get a diameter of 2012 DS85 at about 61 km.

scholarly journals ON THE PROBLEM OF THE SPECIFIC FREQUENCY OF GLOBULAR CLUSTERS

2021 ◽  
pp. 137-142
Author(s):  
Ikram Uralbaevich Tadjibaev
Keyword(s):  
Observational Data ◽  
Globular Clusters ◽  
Spiral Galaxies ◽  
Empirical Relationship ◽  
Flux Ratio ◽  
Quadratic Function ◽  
Absolute Magnitude ◽  
Host Galaxy ◽  
Specific Frequency ◽  
The Absolute

In the article, on the basis of observational data the problems of the specific frequency of globular clusters are studied. Possible relationships between them and the absolute stellar magnitude of their host galaxy are considered, where the observational data published in the literature were presented. It should be noted that before us the relationship between the specific frequency and the absolute magnitude is shown as exponential functions. An empirical relationship between the specific frequency and the absolute value of the host galaxy were obtained and showed that the dependence of the specific frequency on the absolute magnitude is not linear, but has a quadratic function. It is also shown that the specific frequency determines the number of globular clusters in a given galaxy relative to our Galaxy. Also in the article, based on the results of studies of the specific frequency, some discussions are presented related to the origin and evolution of globular clusters. The results obtained show that the ratios of the specific frequency to the luminosity of the host galaxy are different. Variations in the specific frequency of elliptical galaxies are associated with variations in the mass-to-luminous flux ratio. This may be due to the fact that the number of globular clusters in spiral galaxies per unit of luminosity of the halo and not of the entire galaxy. Analysis of the observational data shows that the values of the specific frequency of spiral galaxies are 5–6 times less than that of giant elliptical ones. As a result of the results of studies of the specific frequency of the globular clusters, unsolved problems are listed and possible solutions are shown. It is noted that the problem posed will be solved even more accurately if it is considered by the types of galaxies

scholarly journals Long-term photometric monitoring of the dwarf planet (136472) Makemake

2019 ◽  
Vol 625 ◽  
pp. A46 ◽  
Author(s):  
T. A. Hromakina ◽  
I. N. Belskaya ◽  
Yu. N. Krugly ◽  
V. G. Shevchenko ◽  
J. L. Ortiz ◽  
...  
Keyword(s):  
Broad Band ◽  
Spherical Shape ◽  
Absolute Magnitude ◽  
Photometric System ◽  
Small Peak ◽  
Photometric Observations ◽  
The Absolute ◽  
Photometric Monitoring ◽  
Absolute Magnitudes

Aims. We studied the rotational properties of the dwarf planet Makemake. Methods. The photometric observations were carried out at different telescopes between 2006 and 2017. Most of the measurements were acquired in BVRI broad-band filters of a standard Johnson-Cousins photometric system. Results. We found that Makemake rotates more slowly than was previously reported. A possible lightcurve asymmetry suggests a double-peaked period of P = 22.8266 ± 0.0001 h. A small peak-to-peak lightcurve amplitude in R-filter A = 0.032 ± 0.005 mag implies an almost spherical shape or near pole-on orientation. We also measured BVRI colours and the R-filter phase-angle slope and revised the absolute magnitudes. The absolute magnitude of Makemake has remained unchanged since its discovery in 2005. No direct evidence of a newly discovered satellite was found in our photometric data; however, we discuss the possible existence of another larger satellite.

scholarly journals The Absolute Magnitude of the Early-Type MK Standards From Hipparcos Parallaxes

1998 ◽  
Vol 11 (1) ◽  
pp. 566-566
Author(s):  
C. Jaschek ◽  
A.E. Gómez
Keyword(s):  
Main Sequence ◽  
Rotational Velocity ◽  
Wide Band ◽  
Absolute Magnitude ◽  
Interstellar Extinction ◽  
Early Type ◽  
Class V ◽  
Luminosity Class ◽  
The Absolute ◽  
Absolute Magnitudes

We have analysed the standards of the MK system in the B0-F5 spectral region with the help of Hipparcos parallaxes, using only stars for which the error on the absolute magnitude is ≤ 0.3 mag. The sample stars (about one hundred) were scrutinized for companions and for interstellar extinction. We find that the main sequence is a wide band and that, although in general giants and dwarfs have different absolute magnitudes, the separation between luminosity class V and III is not clear. We conclude that there is no strict relation between luminosity class and absolute magnitude. The relation is only a statistical one and has a large intrinsic dispersion. We have analysed similarly the system of standards defined by Garrison and Gray (1994) separating low and high rotational velocity standards. We find similar effects as in the original MK system.

scholarly journals Observational Data and Orbits of the Asteroids Discovered at the Molėtai Observatory in 2008–2009

2016 ◽  
Vol 25 (4) ◽  
Author(s):  
K. Černis ◽  
I. Wlodarczyk ◽  
J. Zdanavičius
Keyword(s):  
Observational Data ◽  
Minor Planet ◽  
Orbital Elements ◽  
Main Belt ◽  
Ccd Observations ◽  
Near Earth Objects ◽  
Asteroids And Comets

AbstractWe present the statistics of the asteroids observed and discovered at the Molėtai Observatory, Lithuania, in 2008–2009 within the project for astrometric observations of the near-Earth objects (NEOs), the main belt asteroids and comets. CCD observations of the asteroids were obtained with the 35/51-cm Maksutov-type meniscus telescope. In the Minor Planet Circulars and the Minor Planet Electronic Circulars (2008–2009), 11 900 astrometric positions of 2522 asteroids were published. Among them 95 were new asteroids, including four belonging to the Trojan group: (352655) 2008QX28, 2008 SE8, (353194) 2009 SM100 and (264068) 2009 SQ148. For the asteroids discovered at Molėtai their precise orbits are calculated. Because of short observational arc, a few asteroids have low-precision orbits and some asteroids are considered lost. For the three Main Belt asteroids with low-precision orbital elements, 2008 QP32, 2008 SD8 and 2008 SG150, we present their ephemerides for 2017. They can be brighter than 20 mag.

scholarly journals The Luminosity Determination

1995 ◽  
Vol 10 ◽  
pp. 399-402
Author(s):  
A.E. Gómez ◽  
C. Turon
Keyword(s):  
Main Sequence ◽  
Small Volume ◽  
Absolute Magnitude ◽  
Fitting Procedure ◽  
Trigonometric Parallaxes ◽  
The Mean ◽  
The Absolute ◽  
Absolute Magnitudes ◽  
Kinematical Data ◽  
Magnitude Determination

The Hertzprung-Russel (HR) diagram luminosity calibration relies basically on three kinds of data: trigonometric parallaxes, kinematical data (proper motions and radial velocities) and cluster distances obtained by the zero-age main sequence fitting procedure. The most fundamental method to calculate the absolute magnitude is the use of trigonometric parallaxes, but up to now, accurate data only exist for stars contained in a small volume around the sun. Individual absolute magnitudes are obtained using trigonometric parallaxes or photometric and spectroscopic calibrations. In these calibrations the accuracy on the absolute magnitude determination ranges from ±0.m2 in the main sequence to ±0m5 in the giant branch. On the other hand, trigonometric parallaxes, kinematical data or cluster distances have been used to make statistical calibrations of the absolute magnitude. The standard error on the mean absolute magnitude calibrations ranges from ±0m3 to ±0m6 on the mean sequence, from ±0m5 to ±0m7 on thegiant branch and is of about 1mfor supergiants.Future improvements in the absolute magnitude determination will depend on the improvement of the basic data from the ground and space. A brief overview of the new available data is presented. In particular, the analysis of the first 30 months data of the Hipparcos mission (H30) (from the 37 months data of the whole mission) allows to perform a statistical evaluation of the improvements expected in the luminosity determination.

Observational Data and Orbits of the Asteroids Discovered at the Baldone Observatory in 2008–2013

2015 ◽  
Vol 24 (3) ◽  
Author(s):  
K. Černis ◽  
I. Wlodarczyk ◽  
I. Eglitis
Keyword(s):  
Observational Data ◽  
Ccd Camera ◽  
Minor Planet ◽  
Orbital Elements ◽  
Main Belt ◽  
Schmidt Telescope ◽  
Ccd Observations ◽  
Near Earth Objects ◽  
Asteroids And Comets

AbstractThe paper presents statistics of the asteroids observed and discovered at the Baldone Observatory, Latvia, in 2008–2013 within the project for astrometric observations of the near-Earth objects (NEOs), the main belt asteroids and comets. CCD observations of the asteroids were obtained with the 0.80/1.20 m, f/3 Schmidt telescope and a ST-10XME 15 × 10 mm CCD camera. In the Minor Planet Circulars and the Minor Planet Electronic Circulars (2008–2013) we published 3511 astrometric positions of 826 asteroids. Among them, 43 asteroids were newly discovered at Baldone. For 36 of these asteroids the precise orbits are calculated. Because of short observational arc and small number of observations, a few asteroids have low-precision orbits and their tracks have been lost. For seven objects with poorly known orbits we present their ephemerides for 2015–2016. The orbits and the evolution of orbital elements of two asteroids, (428694) 2008 OS9 from the Apollo group and the Centaur (330836) Orius (2009 HW77), are recalculated including new observations obtained after 2011.

scholarly journals The Parallaxes of U Gem Variables

1979 ◽  
Vol 53 ◽  
pp. 494-494
Author(s):  
Karl W. Kamper
Keyword(s):  
Confidence Level ◽  
Absolute Magnitude ◽  
Weighted Mean ◽  
Quiescent Phase ◽  
A Value ◽  
The Mean ◽  
The Absolute ◽  
Absolute Magnitudes

An Allegheny parallax series of SS Cyg, consisting of 52 exposures obtained on 15 nights, was recently measured on the PDS microphotometer at the David Dunlap Observatory, and a value of (m.e.) derived for the absolute parallax. This is close to the mean of the two previous discordant measures for this star given in the table below. The weighted mean of the three determinations implies that the absolute magnitude, at quiescent phase, of the star is between 7.0 and 9.0 formally at a 90% confidence level. Recent parallax determinations made at Lick by Vasilevskls et al. (1975) for three other stars, listed below along with the Mt. Wilson value for U Gem, imply even fainter absolute magnitudes.

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