A Variable Asymmetry in the Circumstellar Disk of HH 30

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

34

Accretion, Accretion Disks, Stars: Circumstellar Matter, Stars: Individual: Alphanumeric: Hh 30, Stars: Pre-Main-Sequence

Scientific paper

We report Hubble Space Telescope observations of variability within the reflection nebulosity of HH 30, a compact bipolar nebula that is a nearly edge-on accretion disk system. A dramatic lateral asymmetry appeared in the upper reflection nebula in the spring of 1998, but was largely absent in 1994 and 1995 images. The variability timescale is much shorter than disk dynamical timescales at the projected radius of the asymmetry, which indicates that its origin is a variable illumination pattern projected onto the outer disk by changes in the inner disk or the central star. Orbital motion of coherent clumps or voids in the inner disk at radii of a few AU might produce such an effect. Another possibility recently proposed is accretion hot spots near the star's magnetic poles which produce broad beams of light sweeping across the disk as the star rotates. Simulated images of a disk illuminated by such a central ``lighthouse'' are a reasonable match to the bright lateral asymmetry in the upper nebula of HH 30. However, a model with identical opposed hot spots is excluded by the absence of a prominent asymmetry in the lower reflection nebula. Further temporal monitoring of the system is needed to better characterize the nebular variability and establish its physical origin.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

A Variable Asymmetry in the Circumstellar Disk of HH 30 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A Variable Asymmetry in the Circumstellar Disk of HH 30, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Variable Asymmetry in the Circumstellar Disk of HH 30 will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1124083

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.