CO gas and dust outbursts from Centaur 29P/Schwassmann-Wachmann. (arXiv:2001.09537v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Wierzchos_K/0/1/0/all/0/1">Kacper Wierzchos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Womack_M/0/1/0/all/0/1">Maria Womack</a>
29P/Schwassmann Wachmann is an unusual solar system object. Originally
classified as a short-period comet, it is now known as a Centaur that recently
transferred to its current orbit, and may become a Jupiter Family comet. It has
exhibited a dust coma for over 90 years, and regularly undergoes significant
dust outbursts. Carbon monoxide is routinely detected in high amounts and is
typically assumed to play a large role in generating the quiescent dust coma
and outbursts. To test this hypothesis, we completed two 3-month long observing
campaigns of the CO J=2-1 rotational line using the Arizona Radio Observatory
10m Sub-millimeter Telescope during 2016 and 2018-2019, and compared the
results to visible magnitudes obtained at the same time. As the Centaur
approached its 2019 perihelion, the quiescent dust coma grew $sim$45% in
brightness, while it is unclear whether the quiescent CO production rate also
increased. A doubling of the CO production rate on 2016 Feb 28.6 UT did not
trigger an outburst nor a rise in dust production for at least 10 days.
Similarly, two dust outbursts occurred in 2018 while CO production continued at
quiescent rates. Two other dust outbursts may show gas involvement. The data
indicate that CO- and dust-outbursts are not always well-correlated. This may
be explained if CO is not always substantially incorporated with the dust
component in the nucleus, or if CO is primarily released through a porous
material. Additionally, other minor volatiles or physical processes may help
generate dust outbursts.
29P/Schwassmann Wachmann is an unusual solar system object. Originally
classified as a short-period comet, it is now known as a Centaur that recently
transferred to its current orbit, and may become a Jupiter Family comet. It has
exhibited a dust coma for over 90 years, and regularly undergoes significant
dust outbursts. Carbon monoxide is routinely detected in high amounts and is
typically assumed to play a large role in generating the quiescent dust coma
and outbursts. To test this hypothesis, we completed two 3-month long observing
campaigns of the CO J=2-1 rotational line using the Arizona Radio Observatory
10m Sub-millimeter Telescope during 2016 and 2018-2019, and compared the
results to visible magnitudes obtained at the same time. As the Centaur
approached its 2019 perihelion, the quiescent dust coma grew $sim$45% in
brightness, while it is unclear whether the quiescent CO production rate also
increased. A doubling of the CO production rate on 2016 Feb 28.6 UT did not
trigger an outburst nor a rise in dust production for at least 10 days.
Similarly, two dust outbursts occurred in 2018 while CO production continued at
quiescent rates. Two other dust outbursts may show gas involvement. The data
indicate that CO- and dust-outbursts are not always well-correlated. This may
be explained if CO is not always substantially incorporated with the dust
component in the nucleus, or if CO is primarily released through a porous
material. Additionally, other minor volatiles or physical processes may help
generate dust outbursts.
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