2010A&A...520A..94G


C.D.S. - SIMBAD4 rel 1.7 - 2021.04.12CEST02:07:08

2010A&A...520A..94G - Astronomy and Astrophysics, volume 520, A94-94 (2010/9-2)

Discovery of ``isolated'' co-moving T Tauri stars in Cepheus.

GUILLOUT P., FRASCA A., KLUTSCH A., MARILLI E. and MONTES D.

Abstract (from CDS):

During the course of a large spectroscopic survey of X-ray active late-type stars in the solar neighbourhood, we discovered four lithium-rich stars packed within just a few degrees on the sky. Although located in a sky area rich in CO molecular regions and dark clouds, the Cepheus-Cassiopeia complex, these very young stars are projected several degrees away from clouds in front of an area void of interstellar matter. As such, they are very good ``isolated'' T Tauri star candidates. We present optical observations of these stars conducted with 1-2m class telescopes. We acquired high-resolution optical spectra as well as photometric data allowing us to investigate in detail their nature and physical parameters with the aim of testing the ``runaway'' and ``in-situ'' formation scenarios. Their kinematical properties are also analyzed to investigate their possible connection to already known stellar kinematic groups. We use the cross-correlation technique and other tools developed by us to derive accurate radial and rotational velocities and perform an automatic spectral classification. The spectral subtraction technique is used to infer chromospheric activity level in the Hα line core and clean the spectra of photospheric lines before measuring the equivalent width of the lithium absorption line. Both physical (lithium content, chromospheric, and coronal activities) and kinematical indicators show that all stars are very young, with ages probably in the range 10-30Myr. In particular, the spectral energy distribution of TYC4496-780-1 displays a strong near- and far-infrared excess, typical of T Tauri stars still surrounded by an accretion disc. They also share the same Galactic motion, proving that they form a homogeneous moving group of stars with the same origin. The most plausible explanation of how these ``isolated'' T Tauri stars formed is the ``in-situ'' model, although accurate distances are needed to clarify their connection with the Cepheus-Cassiopeia complex. The discovery of this loose association of ``isolated'' T Tauri stars can help to shed light on atypical formation processes of stars and planets in low-mass clouds.

Abstract Copyright:

Journal keyword(s): stars: fundamental parameters - stars: pre-main sequence - stars: formation - stars: kinematics and dynamics - stars: late-type - X-rays: stars

Simbad objects: 24

goto Full paper

goto View the reference in ADS

Number of rows : 24

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 BD+78 853 * 00 00 41.2135361241 +79 40 39.894777837 11.07 10.91 10.29 9.77 9.42 G2V 9 0
2 TYC 4496-780-1 SB* 00 13 40.5769014290 +77 02 10.908456883 10.57 10.42 9.78   8.858 ~ 6 0
3 2MASS J00380610+7903206 Y*? 00 38 06.1241317372 +79 03 20.633467058 11.74 11.21 11.34 9.96 9.60 K1V 13 0
4 BD+78 19 SB* 00 39 40.2195009802 +79 05 30.772124831 10.38 10.29 9.57 9.11 8.89 ~ 6 0
5 LDN 1333 DNe 02 26 04 +75 28.5           ~ 53 0
6 Cl Melotte 22 OpC 03 47 00 +24 07.0           ~ 3073 0
7 Cl Melotte 25 OpC 04 26 54.00 +15 52 00.0           ~ 2752 0
8 NAME Tau-Aur Complex SFR 04 30 +25.0           ~ 1251 0
9 NAME Taurus Complex SFR 04 41.0 +25 52           ~ 3679 0
10 IC 2391 OpC 08 40 32 -53 02.0           ~ 735 0
11 NAME UMa Region reg 11 00 +50.0           ~ 318 0
12 NAME Cha-Mus DNe 12 15 -76.7           ~ 27 0
13 NAME Ursa Major Moving Group MGr 12 32 +57.0           ~ 392 2
14 IRAS 20582+7724 Y*O 20 57 12.9187221407 +77 35 43.655738044           ~ 113 0
15 LDN 1228 DNe 20 57 13 +77 35.8           ~ 122 0
16 LDN 1241 DNe 21 50.0 +76 44           ~ 16 0
17 NAME Cep Cloud SFR 22 00.0 +76 30           ~ 113 0
18 LDN 1251 DNe 22 36.1 +75 16           ~ 99 0
19 HD 220140 RS* 23 19 26.6384866318 +79 00 12.671002116   8.43 7.54 7.17 6.76 G9V 131 1
20 LDN 1259 DNe 23 22.9 +74 16           ~ 11 0
21 LDN 1261 DNe 23 27.0 +74 17           ~ 11 0
22 NAME Cep Flare MoC 23 34 +72.0           ~ 107 0
23 NAME Castor Moving Group As* ~ ~           ~ 117 1
24 NAME Per-Tau reg ~ ~           ~ 18 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2010A&A...520A..94G and select 'bookmark this link' or equivalent in the popup menu


2021.04.12-02:07:08

© Université de Strasbourg/CNRS

    • Contact