Kavli Affiliate: Moritz Guenther
| First 5 Authors: Michihiro Takami, Tracy L. Beck, P. Christian Schneider, Hans Moritz Guenther, Marc White
| Summary:
For the active T-Taur star RW Aur A we have performed long-term (~10 yr)
monitoring observations of (1) jet imaging in the [Fe II] 1.644-micron emission
line using Gemini-NIFS and VLT-SINFONI; (2) optical high-resolution
spectroscopy using CFHT-ESPaDOnS; and (3) V-band photometry using the CrAO
1.25-m telescope and AAVSO. The latter two observations confirm the correlation
of time variabilities between (A) the Ca II 8542 A and O I 7772 A line profiles
associated with magnetospheric accretion, and (B) optical continuum fluxes. The
jet images and their proper motions show that four knot ejections occurred at
the star over the past ~15 years with an irregular interval of 2-6 years. The
time scale and irregularity of these intervals are similar to those of the
dimming events seen in the optical photometry data. Our observations show a
possible link between remarkable (Delta_V < -1 mag.) photometric rises and jet
knot ejections. Observations over another few years may confirm or reject this
trend. If confirmed, this would imply that the location of the jet launching
region is very close to the star (r <<0.1 au) as predicted by some jet
launching models. Such a conclusion would be crucial for understanding disk
evolution within a few au of the star, and therefore possible ongoing planet
formation at these radii.
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