217P/LINEAR is breaking up or giving birth?

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Hello from Hawaii,
I am in vacation so this post will be brief. David Cardenosa from the Bootes Obs, Boecillo, Valladolid in Spain (observatory code J05) reported on the MPML list an unusual observation of the comet 217P/Linear, I thought some of you may be interested in observing this target.

Observation of the comet 217/P Linear taken from J05 Bootes Observatory (Spain)

Observation of the comet 217/P Linear taken from J05 Bootes Observatory (Spain)

The observation of 217P/LINEAR  is shown on the left. David Cardenosa noticed a new large jet toward the astronomical west and a change in the shape of the tail. After processing it using sharp edge filtering (below), one can see that the large jet is coming from a second feature like if the comet gave birth to a second one. :-)

Subsequent observations taken by E. Guido & G. Sostero confirmed the unusual aspect of 217P/LINEAR. Theu mentioned that “A spiralling arclet about 1.5 arcmin long is emanating from the central condensation in clockwise direction.Arclet are temporary phenomena in the cometary coma that are related with fragmentation events of the nucleusand confirmed  the presence of two tails slightly shifted by ~10 deg (see image here).

It is very probable that 217P/LINEAR is breaking up. Follow up observations from all type of telescopes will be useful, spectroscopy as well since it mayhelp to detect fresh material from the interior of the comet. The coordinates (DEC = -02,RA=2h) of the comet can be find in the MPEC ephemeris. Its expected magnitude is ~12 in visible but it should be significantly brighter (V=10-11) because of the breakup.

Let me know if you could observe it. This is also a nice target to show students the variability of the cometary activity. I kind of remember that the schools are starting soon so why not choosing it as a lab target?

2 more days of vacation…

clear skies,


About Franck Marchis

Dr. Franck Marchis is a Senior Researcher and Chair of the Exoplanet Group at the Carl Sagan Center of the SETI Institute since July 2007. Over the past 19 years, he has dedicated his research to the study of our solar system, specifically the search for asteroids with moons, using mainly ground-based telescopes equipped with adaptive optics. More recently, he has been also involved in the definition of new generation of AOs for 8 -10 m class telescopes and future Extremely Large Telescopes. He has developed algorithms to process and enhance the quality of images, both astronomical and biological. His currently involved in the Gemini Planet Imager Exoplanet Survey, which consists in imaging exoplanets using an extreme AO system for the Gemini South telescope. This new instrument is capable of imaging and recording spectra of young Jupiter-like exoplanets orbiting around nearby stars.

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