Elliptical Orbit of Asteroid 1986 QE1

1989 ◽  
Vol 12 ◽  
pp. 21-24
Author(s):  
H. Debehogne ◽  
L.E. Machado ◽  
S. Vaz ◽  
E.R. Netto
Keyword(s):  
Photographic Plate ◽  
Elliptical Orbit ◽  
Orbital Elements ◽  
European Southern Observatory ◽  
Geocentric Distance ◽  
Before And After

We present the orbital elements of asteroid QE1 (pro visional designation) identified in august 26, 1986, on a photographic plate obtained at the GPO telescope of the European Southern Observatory (ESO), La Silla, Chile, as well as the positions (AR and Dec) referred to 1950.0. Residues (0 - C) of the position in AR and Dec of the asteroid are given, both before and after applying variation in the geocentric distance.

scholarly journals Discovery and Orbit of Asteroid 1979 HB (ESO, La Silla)

1979 ◽  
Vol 3 ◽  
pp. 1-5
Author(s):  
H Debehogne ◽  
J. F. Caldeira
Keyword(s):  
Least Squares ◽  
Rio De Janeiro ◽  
Proper Motions ◽  
Orbital Elements ◽  
European Southern Observatory ◽  
Measuring Machine

This paper presents orbital elements for the asteroid 1979 HB discovered during the period from april 20 through april 29 , 1979 at the GPO telescope (f= 4m, d2 40 cm) of the European Southern Observatory - ESO, La Silla, Chile. The orbit has been computed by Gauss-Encke Method (with successive improvements of the geocentric distances based on 21 positions). All plates were measured at the Ascorecord Zeiss/Jena measuring machine of the Valongo Observatory . The positions were computed by means of dependences and of the least squares, with the computer Burrough's B6700 of the Núcleo de Computação Eletrônica - NCE, of the Universidade Federal do Rio de Janeiro . The observations are reduced to the equinox 1950, and the coordinates of the reference stars, taken from the SAO Stars Catalogue, are corrected for proper motions.

scholarly journals Computation of the Different Errors in the Ballistic Missiles Range

2011 ◽  
Vol 2011 ◽  
pp. 1-16 ◽  
Author(s):  
F. A. Abd El-Salam ◽  
S. E. Abd El-Bar
Keyword(s):  
Ballistic Missile ◽  
Elliptical Orbit ◽  
Orbital Elements ◽  
Orbit Plane ◽  
Ballistic Missiles ◽  
Explicit Expressions

The ranges of the ballistic missile trajectories are very sensitive to any kind of errors. Most of the missile trajectory is a part of an elliptical orbit. In this work, the missile problem is stated. The variations in the orbital elements are derived using Lagrange planetary equations. Explicit expressions for the errors in the missile range due to the in-orbit plane changes are derived. Explicit expressions for the errors in the missile range due to the out-of-orbit plane changes are derived when the burnout point is assumed on the equator.

scholarly journals Re-Evaluation Solution Methods for Kepler's Equation of an Elliptical Orbit

2019 ◽  
pp. 2269-2279
Author(s):  
Rasha H. Ibrahim ◽  
Abdul-Rahman H. Saleh
Keyword(s):  
Orbital Period ◽  
Circular Orbit ◽  
Line Element ◽  
Elliptical Orbit ◽  
Orbital Elements ◽  
Initial Value ◽  
Matlab Program ◽  
Solution Methods ◽  
Newton Raphson ◽  
Good Agreement

An evaluation was achieved by designing a matlab program to solve Kepler’s equation of an elliptical orbit for methods (Newton-Raphson, Danby, Halley and Mikkola). This involves calculating the Eccentric anomaly (E) from mean anomaly (M=0°-360°) for each step and for different values of eccentricities (e=0.1, 0.3, 0.5, 0.7 and 0.9). The results of E were demonstrated that Newton’s- Raphson Danby’s, Halley’s can be used for e between (0-1). Mikkola’s method can be used for e between (0-0.6).The term  that added to Danby’s method to obtain the solution of Kepler’s equation is not influence too much on the value of E. The most appropriate initial Gauss value was also determined to be (En=M), this initial value gave a good result for (E) for these methods regardless the value of e to increasing the accuracy of E. After that the orbital elements converting into state vectors within one orbital period within time 50 second, the results demonstrated that all these four methods can be used in semi-circular orbit, but in case of elliptical orbit Danby’s and Halley’s method use only for e ≤ 0.7, Mikkola’s method for e ≤ 0.01 while Newton-Raphson uses for e < 1, which considers more applicable than others to use in semi-circular and elliptical orbit. The results gave a good agreement as compared with the state vectors of Cartosat-2B satellite that available on Two Line Element (TLE).

Artificial satellite orbit computations

1966 ◽  
Vol 25 ◽  
pp. 363-371
Author(s):  
P. Sconzo
Keyword(s):  
Artificial Satellite ◽  
Satellite Orbit ◽  
Artificial Satellites ◽  
Orbital Elements ◽  
Differential Correction ◽  
Gravitational Effects ◽  
Short Intervals ◽  
The Subject ◽  
Introductory Discussion ◽  
Orbit Computation

In this paper an orbit computation program for artificial satellites is presented. This program is operational and it has already been used to compute the orbits of several satellites.After an introductory discussion on the subject of artificial satellite orbit computations, the features of this program are thoroughly explained. In order to achieve the representation of the orbital elements over short intervals of time a drag-free perturbation theory coupled with a differential correction procedure is used, while the long range behavior is obtained empirically. The empirical treatment of the non-gravitational effects upon the satellite motion seems to be very satisfactory. Numerical analysis procedures supporting this treatment and experience gained in using our program are also objects of discussion.

Statistical results on discovered near-Earth asteroids

1999 ◽  
Vol 173 ◽  
pp. 81-86
Author(s):  
S. Berinde
Keyword(s):  
Dynamical Evolution ◽  
Minor Planet ◽  
Orbital Elements ◽  
The Earth ◽  
Near Earth Asteroids ◽  
Statistical Results

AbstractThe first part of this paper gives a recent overview (until July 1st, 1998) of the Near-Earth Asteroids (NEAs) database stored at Minor Planet Center. Some statistical interpretations point out strong observational biases in the population of discovered NEAs, due to the preferential discoveries, depending on the objects’ distances and sizes. It is known that many newly discovered NEAs have no accurately determinated orbits because of the lack of observations. Consequently, it is hard to speak about future encounters and collisions with the Earth in terms of mutual distances between bodies. Because the dynamical evolution of asteroids’ orbits is less sensitive to the improvement of their orbital elements, we introduced a new subclass of NEAs named Earth-encounter asteroids in order to describe more reliably the potentially dangerous bodies as impactors with the Earth. So, we pay attention at those asteroids having an encounter between their orbits and that of the Earth within 100 years, trying to classify these encounters.

Models of comets with strongly variable nongravitational effects

1999 ◽  
Vol 173 ◽  
pp. 381-387
Author(s):  
M. Królikowska ◽  
G. Sitarski ◽  
S. Szutowicz
Keyword(s):  
Cometary Nucleus ◽  
Spin Axis ◽  
Reactive Force ◽  
Orbital Elements ◽  
Cometary Nuclei ◽  
Short Period ◽  
Basic Parameters ◽  
Polar Radius ◽  
Cometary Activity ◽  
Nongravitational Effects

AbstractThe nongravitational motion of five “erratic” short-period comets is studied on the basis of published astrometric observations. We present the precession models which successfully link all the observed apparitions of the comets: 21P/Giacobini-Zinner, 31P/Schwassmann-Wachmann 2, 32P/Comas Solá, 37P/Forbes, and 43P/Wolf-Harrington. We used the Sekanina's forced precession model of the rotating cometary nucleus to include the nongravitational terms into equations of the comet's motion. Values of six basic parameters (four connected with the rotating comet nucleus and two describing the precession of spin-axis of the nucleus) have been determined along the orbital elements from positional observations of the comets. The solutions were derived with additional assumptions which introduce instantaneous changes of modulus of reactive force,Aand of maximum of cometary activity with respect to perihelion time. The present precession models impose some contraints on sizes and rotational periods of cometary nuclei. According to our solutions the nucleus of 21P/Giacobini-Zinner with oblateness along the spin-axis of about 0.32 (equatorial to polar radius of 1.46) is the most oblate among five investigated comets.

Results of Latitude Observations with the Floating Zenith Telescope at Mizusawa: Comparisons between the Results Obtained from the Astronomical and Doppler Satellite Observations

1975 ◽  
Vol 26 ◽  
pp. 461-468
Author(s):  
S. Takagi
Keyword(s):  
Photographic Plate ◽  
Satellite Observations ◽  
Pole Motion

In this article, we intended to see whether we can obtain the same pole motion from two kinds of telescopes: the floating zenith telescope (PZT) and the ILS zenith telescope (VZT). The observations with the PZT have been pursued since 1967.0 with a star list whose star places are taken from the PK4 and its supplement. We revised the method of reduction of the observations with the PZT by adopting a variable scale value for the photographic plate (Takagi et al., 1974).

A Study of the Lambda Virginis System

1976 ◽  
Vol 32 ◽  
pp. 701-712
Author(s):  
D. J. Stickland
Keyword(s):  
Orbital Elements

SummaryThe orbital elements of the SB2 λ Vir have been redetermined and the earlier period of 206 days found to be correct. Both stars have been classified as Am although they exhibit rather different ve.sin i's. An abundance analysis confirms the similarity in metallicity of the two components.

Deformation Replication

1970 ◽  
Vol 28 ◽  
pp. 280-281
Author(s):  
J. Temple Black
Keyword(s):  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Rake Face ◽  
Orthogonal Machining ◽  
Aluminum Chips ◽  
Before And After ◽  
Materials Used ◽  
Glass Knife ◽  
Very High

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.

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