Wednesday, 5 December 2007

Comet 17P/Holmes

After some time dedicated to other astronomical topics, I'm back to share my images of comet 17P/Holmes.

This comet suffered a very spectacular eruption on Oct. 24, 2007. In less than 24 hours, the 17th magnitude bright of the comet increases by a factor of nearly a million, becoming a naked-eye object. From this day it has been expanding while it was crossing the constellation Perseus. Now, it is vanishing and it nos as spectacular than before but now it has a diameter bigger than the Moon that can be very well appreciated by the naked-eye from very dark places.

During the first two weeks the comet was bright enough to be observed from the center of the cities. Thus, I put my equipment in front fo the window and I captured the images I show you. All the images have been captured with a C8 SCT and a Canon 400D camera with exposures of 20 seconds at 1600 ASA.

The following image shows the evolution of the coma of the comet between 3 days after the eruption and one week.

The next image is an anagliph of the previous images using the aparent movement of the comet on the stars background. If you have red&blue glasses you can appreciate a 3D view of the comet in front of the stars.

An animated gif helps to evaluate the comet growth in during only one week.

The last image was taken with 30 seconds exposure on Oct. 30 at 19:30 GMT. Later the histogram was forced a little to show the exterior green halo of the comet. It is erupted matter that emits green light because its interaction with the solar wind. It is green because its composition and it can be well observed because this matter has not enough density to reflects sufficient solar light (mainly white) to mask this emission.

Additional images of the comet showing its evolution from the first eruption until now can be found in this webpage or this one.