Document Type

Article

Publication Date

7-1-2012

Publication Title

Journal of the Southeastern Association fo Reasearch in Astronomy

Volume

6

Publisher

Southeastern Association for Research in Astronomy

Abstract

In T Tauri stars, the Brackett gamma line strength is a reliable indicator of accretion luminosity. Among intermediate mass young stars, Herbig Ae stars also show this correlation, but in Herbig Be stars the Brgamma line flux significantly overpredicts accretion luminosity. This Brgamma excess in Herbig Be stars is thought to arise from a spatially extended outflow. Using commissioning data from the LUCIFER spectrograph on the 8.4-meter Large Binocular Telescope (LBT), we present a spectro-astrometric study of two Herbig Ae/Be stars, the HAe star MWC480 and the HBe star HD 259431. In both stars, an extended Brgamma source can be ruled out down to 0.001 arcsec at the 1sigma level. Using currently accepted parallax values of 137 ± 25 pc and 173 ± 37 pc, this implies a lack of spatially extended structure beyond 0.131 ± 0.024 AU for MWC 480 and 0.166 ± 0.036 AU for HD 259431.

Comments

This manuscript has been published in the Journal of the Southeastern Association for Research in Astronomy. Please find the published version here (note that a subscription may be necessary to access this version):

http://www.jsara.org/JSARA-V06/ms0601-Rice+Brittain.pdf

Southeastern Association for Research in Astronomy holds the copyright in this article.

Download

Share

COinS