Comet C/2009 R1 (McNaught) - Animation & Images

Comet C/2009 R1 has been discovered in September 2009 by Robert H. McNaught in the course of Australia’s Siding Spring Survey.

For more information about the discovery of this comet, please see our previous post:
http://remanzacco.blogspot.com/2009/09/new-comet-discovery-c2009-r1-mcnaught.html

The comet is now around magnitude 7.5 and it will be a nice binocular object. Throughout this apparition it will be low in the east or northeast when dawn begins to brighten.

In our images, taken on May 26, is clearly visible a nice disconnection event (DE) in the plasma tail of the comet C/2009 R1. Occasionally due to comet-solar wind interaction, the entire plasma tail or part of it separates from the comet and drift away (antisunward), followed by simultaneous renewal of the plasma tail. This phenomena is called a disconnection event.




Here & here you can see bigger versions of this image:


Wide-field animation of comet C/2009 R1 (May 26, 2010), showing the DE event:

Wide-Field Image (May 26, 2010):

by Ernesto Guido & Giovanni Sostero

Comet C/2008 A1 (McNaught)

Below you can see our image of comet  C/2008 A1 taken on 2008, Jan. 11.3. Click on the image for a bigger version:

In our stacking is possible to appreciate a nice coma, nearly 30arcsec across, elongated toward North-East. The total magnitude (unfiltered CCD) is nearly 15, while the Afrho calculation (proxy of the dust abundance within the coma) provide a value close to 670 +/-50 cm (with a photometric profile very flat between 15,000 and 40,000 Km from the central condensation).

This seems to indicate an active object, if we consider that currently this comet is nearly 4 AU from the Sun (inbound). The preliminary orbital elements, published by the Minor Planet Center in M.P.E.C. 2008-A48, show that this comet will remain a mainly southern object, with perihelion occuring in November 2008, and a total m1 considered to be nearly magn. 10 at its best.

Giovanni Sostero and Ernesto Guido