Remember Me
Or use your Academic/Social account:


Or use your Academic/Social account:


You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.


Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message


Verify Password:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
Oliveira, J. M.; Jeffries, R. D.; van Loon, J. Th.; Kenyon, M. J. (2003)
Languages: English
Types: Unknown
Subjects: QB, QC, Astrophysics

Classified by OpenAIRE into

arxiv: Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics
The sigma Orionis cluster is a young association evolving under the disruptive influence of its massive O-star namesake. We are analysing this cluster as part of a program to characterise the influence of O-stars on the early stages of stellar evolution. At an age of approximately 4 Myr, this cluster is at a crucial stage in terms of disk evolution and therefore it is a key case to better constrain disk dissipation timescales. We have obtained RI photometry and optical spectroscopy of the sigma Ori cluster; we have analysed the Li I and Na I features to establish cluster membership. We have thus gathered a unique sample of spectroscopically confirmed low-mass cluster members and brown dwarfs. Disk frequencies from K-band excesses from 2MASS suggest that less than 7% of the very low-mass sigma Ori members have disks, in stark contrast with even younger clusters (e.g. Trapezium). However, near-infrared disk frequencies have to be taken with caution. We are currently undertaking an L-band (imaging) and mid-infrared (imaging and spectroscopy) program to identify and probe the properties of circumstellar disks around young stars in this cluster. Preliminary results indicate that at least 30% of cluster members have circumstellar disks.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Baraffe I., Chabrier G., Allard F., Hauschildt P., 1998, A&A 337, 403 Barrado y Navascu´es D., B´ejar V.J.S., Mundt R. et al., 2003, A&A in press Bate M.R., Bonnell I.A., Bromm V., 2003, MNRAS 339, 577 B´ejar V.J.S., Mart´ın E.L., Zapatero Osorio M.R. et al., 2001, ApJ 556, 830 Brown A.G.A., 2001, RMxAC, 1, 89
    • Carpenter J.M., Hillenbrand L.A., Skrutskie M.F. et al., 2002, AJ 124, 1001 Comer´on F., Neuh¨auser R., Kaas A., 2000, A&A 359, 269 Haisch K.E., Lada E.A., Lada C.J., 2001, ApJ 553, 153 Natta A., Testi L., 2001, A&A 376, 22
    • Oliveira J.M., Jeffries R.D., Kenyon M.J. et al., 2002, A&A 382, 22 Walter F.M., Wolk S.J., Freyberg M., Schmitt J.H.M.M.,1997, MmSAI 68, 1081 Walter F.M., Alcala J.M., Neuhauser R. et al., 2001, in Protostars and Planets IV, University of Arizona Press, eds. Mannings V., Boss A.P., Russell S.S., 273 Zapatero Osorio M.R., B´ejar V.J.S., Mart´ın E.L. et al., 2000, Sci 290, 103 Zapatero Osorio M.R., B´ejar V.J.S., Pavlenko Y. et al., 2002, A&A 384, 937
  • No related research data.
  • No similar publications.

Share - Bookmark

Cite this article