Hyakutakes closest approach to Earth at march 25, distance 0.1 AU.
AU, Astronomical Unit, 1 AU are the distance between the Earth and the Sun, about 150 million kilometers.
0.1 AU is about 400 times moon distance.
Date :
1996-03-24
Time (UT) :
23:00
Lens/telescope :
Nikon 50mm f/1.4 (f/2.0)
Field (FOV) :
12x12 degree, before cropping
Exp. time :
red 1x60s, green 1x60s, blue 1x60s.
Image process tool :
Meade, Corel Draw.
Processing :
An early processed image with a not so advanced program, oversaturated core.
I had to do something about it, I spent 2 years to develop my own image processing tool in Matlab to do this.
Even if it today sound that it was small size images with 1024x1024 pixels it give
the computer nuts to do it.
Comment :
The bright star just to the left and bottom is Polaris.
The comet is big
with its tail, moon has a diameter of 0.5 degree this
image is about 12 degree wide!
Matlab, Corel Draw. All image processing done by my own developed Matlab routines
Processing :
align, resize, level, cal dark and gamma image processing
Comment :
Now I had bought a set of red, green and blue filter, because I wanted to take color images.
Fast moving, between each color filter change it has moved relative background stars.
From this night it had been reported that the tail had reached 35 degrees length.
That's about three times more compare to what you can see in this photo.
Date :
1996-03-26
Time (UT) :
20:25 to 20:36
Lens/telescope :
Nikon 50mm f/1.4 (f/2.0)
Field (FOV) :
12x12 degree, before cropping
Exp. time :
red 1x20s, green 1x20s, blue 1x20s
Image color calibrated with G2-stars as references (our sun is a G2-star)
Comment :
Three days later, the comet brightness peaked a couple of days earlier at magnitude -1, that is very bright to be a comet.
Date :
1996-04-08
Time (UT) :
19:20
Lens/telescope :
Nikon 50mm f/1.4 (f/2.0)
Field (FOV) :
12x12 degree, before cropping
Filter :
none
Exp. time :
60 seconds
Comment :
The last of my images of Hyakutake, now it's fading away, compare the size with the images two weeks earlier.
The orbital period is 70000 years.
English
Credit: software 'Comet for Windows' from Seiichi Yoshida
