Astronomy Picture of the Day -- Active Comet ISON

NASA ^ | November 16, 2013 | (see photo credit)

[SunkenCiv]

Explanation: Falling through planet Earth's predawn skies toward its close encounter with the Sun on November 28, Comet ISON is coming to life. The much anticipated comet has now been reported to have substantially increased in activity, surging to naked-eye visibility for dark sites and sprouting a more complex tail. ISON's tail stretches over two degrees in this telephoto skyview from southern Kenya, captured on the morning of November 14. Shown in two panels, the enlarged negative version on the right makes details of the long tail easier to trace, including the tail's separated filaments toward the top of the frame. A sungrazer and first time visitor to the inner solar system, the possibility of ISON's survival to become a bright comet in planet Earth's December skies remains a question.

[SunkenCiv]

[Credit & Copyright: Babak Tafreshi (TWAN)]

[SunkenCiv]

Last but not least, this is the second time recently where I've had to post three APoDs on the same day, and managed to get consecutive topic numbers in the process. I'm not proud of the former, but am kind of proud of the latter.

The Big One

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[onyx]

First time visitor, really?
WOW!

[bigheadfred]

three APoDs on the same day

proud of the latter

with heavenly aplomb

kinda makes you a Latter Day Saint

[cicero2k]

Go over to spaceweather.com to see Ison pictures from all over the world.

Comets used to be considered iceballs, but now they are thought of as metal slag the gets arc welded when close to the sun.

[mikrofon]

So I wonder if there will be more metal or ice on ISON ??

[bgill]

There’s a cool band name in there somewhere.

[dr_lew]

Here's the view from Kenya on the morning of Nov 14 in my Starry Night software at slightly larger scale:

Here, as before, Starry Night greatly exaggerates the brightness of the comet, although the tail length is not much longer than the 2 degrees mentioned. ( You can use the celestial latitude marks at the very top for comparison. )

Note NGC 4697, which is a magnitude 11 object, per the Wiki link. In the photo it has a yellowish tint.

Note also that the photo shows many dimmer stars. So what I'm saying is, they're really hyping this thing. If it flairs into magnificence, as they're hoping for, I'll be pleased but very surprised. It just seems to me it's a physically small object.

[SunkenCiv]

Thanks dr_lew. I’ve been seeing what must be Jupiter more or less in the southern sky for the past week (that’s when I actually had a sky to see, the four month overcast has begun).

[SunkenCiv]

Thanks cicero2k.

[SunkenCiv]

;’)

[SunkenCiv]

Used to be the trajectory was considered diagnostic of this — a parabolic trajectory meant that it was in orbit around the Sun, a hyperbolic trajectory meant it was just passing through.

[cicero2k]

I have been trying to shoot Ison myself. It is actually out the window as I type but I’m west of downton Denver and the city lights are too much plus the moon has not set.

We will try again in early December when Ison is on the other side of the sun and will be visible in the dark west sky. By then it could be spectacular as it had passed less than 1M miles from the surface.

[SunkenCiv]

I think they have in common that green tail.