1. Hot Molecular Gas Orbiting Young Stars: Planet Forming Disks or Small Stellar Companions? A look at data taken at the 200” Mount Palomar Telescope, and at NASA’s IRTF on Mauna Kea David Whelan, April 6, 2005

2. Today I will discuss: What Herbig AeBe stars are and how we believe they form Where we went to observe Herbig AeBe stars Some results: expected and unexpected The electromagnetic spectrum and where we are looking in it

3. The infrared IR: roughly =1-200  m spectrumspectrum

4. 1)Condensation of dust and gas 2)Formation of a protostar surrounded by an envelope of gas and dust 3)Young star surrounded by spinning accretion disk. The three theoretical steps for the evolution of intermediate mass stars are: Herbig AeBe stars

5. Hale 200” Telescope Dome

6. The Control Room at the Hale Telescope

7. NASA’s Infrared Telescope Facility, Mauna Kea

8. Some results: possible spectral features and where they come from Molecular features in emission (CO) Molecular features in absorption Atomic features in emission (Br gamma) Molecular features in absorption (cool stars) SUN DISK

9. These next two slides are what two Herbig AeBe Stars’ Spectra look like…

11. …but sometimes, you get something you don’t expect… Ooh! CO bandheads! LOTS of them!

12. It turns out HD 41511 is a binary star, and may look like this image of Gilese A and B http://www.bbc.co.uk/science/space/stars/startypes/index.shtml

13. THE END THANK YOU!