Comet C/2007 N3 (Lulin) on Jan. 5

2009年1月8日10时36分　 English island, 观星手记　

2007 n3, comet lulin, image

[Images Removed]

A total of nine images of Comet Lulin were taken by the Lulin 0.41-m reflector over the night of Jan. 5, and I used every of them to process three impressive images as you have seen above. The first one is a color image, combined from one Blue-band image, one Visual-band image and seven averaged Red-band image, a low-pass FFT (Fast Fourier Transfer) filter was applied to let more details run out. The second image was averaged from seven Red-band image, a suprising ion-tail to the left, at a length of about 15-20′ (the width of the image is 38′), was turned up after the align-and-stack method. Low-pass FFT was applied as well. The third image was processed by the Larson-Sekanina Rotational Gradient method, and it enabled us to see the near-nucleis jets of the comet. At least nine jets were counted besides the ion and the dust tails, and this feature does not be presented on the Jan. 1 and Jan. 2 images. This might be caused by the decreasing distance from the comet to the Earth as well as the sun. All the images were reduced to 600×600 pixel to match the size of my blog, the origin size images can be viewed below.

Update on Jan. 14: Since a complaint about the publication of their images from Lulin Observatory was filed to me yesterday, I have removed all the images about Comet Lulin appeared on my blog, of those taken by the 0.41-m reflector but NOT in the course of Lulin Sky Survey. My profuse apologizes go to Dr. Z. Y. Lin, who is considered to be the legal user of the data; and to those who are involved, including those who had got my permission to use these images earlier. I’ll continuously monitoring the comet and post anything new on my blog, while ensuring only data from Lulin Sky Survey (the program I’m now responsible for) to be publicazed in any cases when the material is involved with Lulin Observatory.