2010A&A...517A..36T


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.09CEST07:07:51

2010A&A...517A..36T - Astronomy and Astrophysics, volume 517, A36-36 (2010/7-1)

A halo blue straggler on a highly eccentric retrograde orbit.

TILLICH A., PRZYBILLA N., SCHOLZ R.-D. and HEBER U.

Abstract (from CDS):

Blue stragglers, which are stars that appear to be younger than they should be, are an important population of unusual stars in both stellar clusters and the halo field of the Galaxy. Most formation scenarios evoke either stellar collisions or binary stars that transfer mass or merge. We investigate high-velocity stars in the Galactic halo and perform a spectral and kinematical analysis to shed light on their nature and origin. Here we report that SDSSJ130005.62+042201.6 (J1300+0422 for short) is an A-type star of unusually large radial velocity (504.6±5km/s). From a quantitative NLTE (and LTE) spectral analysis of medium-resolution optical spectra, the elemental composition is derived. Proper motion measurements combined with a spectroscopic distance estimate allow us to determine its present space velocity. Its kinematical properties are derived by integrating the equation of motion in the Galactic potential. We find J1300+0422 to be metal poor ([M/H]=-1.2) and exhibit an α-element enrichment (0.3-0.4 dex) that is characteristic of the halo population, as confirmed by a kinematical analysis of its 3D space motions, which places it on a highly eccentric retrograde Galactic orbit. The mass of J1300+0422 (1.15±0.10M) is higher than the globular cluster turn-off masses indicating that it is a halo blue straggler star. At a Galactic rest-frame velocity of ≃467km/s, the star travels faster than any known blue straggler but is still bound to the Galaxy.

Abstract Copyright:

Journal keyword(s): stars: kinematics and dynamics - stars: individual: SDSSJ130005.62+042201.6 - blue stragglers - stars: Population II - stars: atmospheres - Galaxy: halo

Simbad objects: 9

goto Full paper

goto View the reference in ADS

Number of rows : 9

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 NGC 188 OpC 00 48 26 +85 15.3           ~ 813 0
2 NAME SMC G 00 52 38.0 -72 48 01   2.79 2.2     ~ 9441 1
3 SDSS J013655.91+242546.0 BS* 01 36 55.9040494172 +24 25 46.003692488           ~ 11 0
4 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 14826 1
5 SDSS J130005.61+042201.6 HB* 13 00 05.6181016130 +04 22 01.694506034           A 5 0
6 SDSS J153935.66+023909.7 HB* 15 39 35.6703436338 +02 39 09.814153470           ~ 9 0
7 SDSS J155352.40+003012.1 BS* 15 53 52.4077080572 +00 30 12.057410381           ~ 2 0
8 NAME Gal Center reg 17 45 40.04 -29 00 28.1           ~ 11537 0
9 M 30 GlC 21 40 22.12 -23 10 47.5     7.10     ~ 913 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2010A&A...517A..36T and select 'bookmark this link' or equivalent in the popup menu


2020.07.09-07:07:51

© Université de Strasbourg/CNRS

    • Contact