2006A&A...449.1281A


Query : 2006A&A...449.1281A

2006A&A...449.1281A - Astronomy and Astrophysics, volume 449, 1281-1288 (2006/4-3)

Astrometric light-travel time signature of sources in nonlinear motion. I. Derivation of the effect and radial motion.

ANGLADA-ESCUDE G. and TORRA J.

Abstract (from CDS):

Very precise planned space astrometric missions and recent improvements in imaging capabilities require a detailed review of the assumptions of classical astrometric modeling. We show that Light-Travel Time must be taken into account in modeling the kinematics of astronomical objects in nonlinear motion, even at stellar distances. A closed expression to include Light-Travel Time in the current astrometric models with nonlinear motion is provided. Using a perturbative approach the expression of the Light-Travel Time signature is derived. We propose a practical form of the astrometric modelling to be applied in astrometric data reduction of sources at stellar distances(d>1pc). We show that the Light-Travel Time signature is relevant at µas accuracy (or even at mas) depending on the time span of the astrometric measurements. We explain how information on the radial motion of a source can be obtained. Some estimates are provided for known nearby binary systemsGiven the obtained results, it is clear that this effect must be taken into account in interpreting precise astrometric measurements. The effect is particularly relevant in measurements performed by the planned astrometric space missions (GAIA, SIM, JASMINE, TPF/DARWIN). An objective criterion is provided to quickly evaluate whether the Light-Travel Time modeling is required for a given source or system.

Abstract Copyright:

Journal keyword(s): astrometry - stars: kinematics - reference systems - time - binaries: general - planetary systems

Simbad objects: 7

goto Full paper

goto View the references in ADS

Number of rows : 7
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 HD 2475 ** 00 28 21.09548 -20 20 06.1774   7.026 6.437     F9VFe+0.5 86 1
2 PSR J0437-47 Psr 04 37 15.7994581776 -47 15 08.544351636           DC 820 0
3 HD 44627B BD* 06 19 12.9988086984 -58 03 20.198341332           L1 120 1
4 HD 110314 SB* 12 40 50.0980475070 +40 31 17.410712189   8.92   7.8   G6 40 0
5 PSR B1257+12 Psr 13 00 03.1075 +12 40 55.155           ~ 495 1
6 * alf Cen ** 14 39 29.71993 -60 49 55.9990   0.4 -0.1     G2V+K1V 886 0
7 * 61 Cyg ** 21 06 53.95 +38 44 57.9           ~ 168 0

To bookmark this query, right click on this link: simbad:objects in 2006A&A...449.1281A and select 'bookmark this link' or equivalent in the popup menu


2022.05.22-00:32:32

© Université de Strasbourg/CNRS

    • Contact