McNaught is still visible from latitude +51N

Well part of it at least...

http://www.digitalsky.org.uk/comets/...chrones001.jpg

http://www.digitalsky.org.uk/comets/...chrones002.jpg
--
Pete
http://www.digitalsky.org.uk

"Pete Lawrence" wrote in message
...
Well part of it at least...

http://www.digitalsky.org.uk/comets/...chrones001.jpg

http://www.digitalsky.org.uk/comets/...chrones002.jpg
--
Wonderful photos. Thanks.

Now, can someone explain something, please?

Last weekend, just before the comet really made itself known in the
antipodes, people were reporting sightings of it in daylight in the northern
hemisphe if you stood beside a building to hide the sun you could see the
comet to the side of the sun. So... Shouldn't we, in the northern
hemisphere, still be able to do this, except that the comet would now appear
below the sun? If it's as bright as it seems to be you'd think this would be
possible. I'm obviously missing something here.... Can someone please tell
me why this isn't possible?

Thanks.

ally

Fantastic !

"Pete Lawrence" wrote in message
...
Well part of it at least...

http://www.digitalsky.org.uk/comets/...chrones001.jpg

http://www.digitalsky.org.uk/comets/...chrones002.jpg
--
Pete
http://www.digitalsky.org.uk

On Sun, 21 Jan 2007 01:29:06 -0000, "a l l y"
wrote:

Last weekend, just before the comet really made itself known in the
antipodes, people were reporting sightings of it in daylight in the northern
hemisphe if you stood beside a building to hide the sun you could see the
comet to the side of the sun. So... Shouldn't we, in the northern
hemisphere, still be able to do this, except that the comet would now appear
below the sun? If it's as bright as it seems to be you'd think this would be
possible. I'm obviously missing something here.... Can someone please tell
me why this isn't possible?

The comet isn't as bright as it was earlier. It peaked about a week ago,
when it was much nearer the Sun. You can still see it in daylight with a
scope or binoculars, but I doubt you can see it naked eye.

While still quite bright, it is the length, structure, and brightness of
the tail that are making this such a striking object. The tail was
nowhere near as long when this was a northern object.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

"a l l y" wrote:

Last weekend, just before the comet really made itself known in the
antipodes, people were reporting sightings of it in daylight in the northern
hemisphe if you stood beside a building to hide the sun you could see the
comet to the side of the sun. So... Shouldn't we, in the northern
hemisphere, still be able to do this, except that the comet would now appear
below the sun? If it's as bright as it seems to be you'd think this would be
possible. I'm obviously missing something here.... Can someone please tell
me why this isn't possible?

The primary reason (at least until recently) is that the comet was
*much* brighter when most of the daylight observations were being
made. I know, the photos all show a 'brilliant' comet in the southern
skies. Furthermore, the presence of tail rays in the northern
hemisphere lend support to a 'brilliant' comet. Nevertheless, Comet
McNaught has dimmed *significantly* from its former daytime
brilliance. Consider this: Not so long ago the comet was reported as
being a magnitude minus 5 to minus 6 object. Now the comet is being
reported as being near magnitude zero! (Consider the difference in
brightness between a 1st magnitude star and a 6th magnitude star. A
difference of 5 or 6 magnitudes is a *huge* difference in brightness!)

More recently another reason has come (or is about to come) into
effect for many northerners: For many, the comet has reached (or is
approaching) the point where it no longer makes it above our horizons
-- even in the daytime!
--
Bill
Celestial Journeys
http://cejour.blogspot.com

On Sun, 21 Jan 2007 02:23:58 GMT, Chris L Peterson
wrote:

On Sun, 21 Jan 2007 01:29:06 -0000, "a l l y"
wrote:

Last weekend, just before the comet really made itself known in the
antipodes, people were reporting sightings of it in daylight in the northern
hemisphe if you stood beside a building to hide the sun you could see the
comet to the side of the sun. So... Shouldn't we, in the northern
hemisphere, still be able to do this, except that the comet would now appear
below the sun? If it's as bright as it seems to be you'd think this would be
possible. I'm obviously missing something here.... Can someone please tell
me why this isn't possible?

The comet isn't as bright as it was earlier. It peaked about a week ago,
when it was much nearer the Sun. You can still see it in daylight with a
scope or binoculars, but I doubt you can see it naked eye.

While still quite bright, it is the length, structure, and brightness of
the tail that are making this such a striking object. The tail was
nowhere near as long when this was a northern object.

I doubt whether it's visible in daylight now. I imaged it last Sunday
(14th) and had trouble seeing it and taking the pictures. I couldn't
quite work out why as there were loads of sightings and images on the
13th (when it was cloudy for me!). Looking at the brightness estimates
the comet had dropped by approximately 2 mags from -6 to -4, making it
much harder to pick out. Look for daylight images of the comet and
you'll see loads on the 13th but very few on the 14th. Here's mine...

http://www.digitalsky.org.uk/comets/...t-daylight.jpg

The last magnitude estimate I saw for this comet was -1.5 so I think a
daylight sighting would be very difficult indeed!

Even if you could see it in daylight, visibility also depends on
location. If you live anywhere above approximately 45N the comet's
head doesn't pop up above the horizon at any time of the day.


--
Pete Lawrence
http://www.digitalsky.org.uk
Last updated June 2006

On Sun, 21 Jan 2007 01:59:56 GMT, "Geoff Smith"
wrote:

Fantastic !

"Pete Lawrence" wrote in message
.. .
Well part of it at least...

http://www.digitalsky.org.uk/comets/...chrones001.jpg

http://www.digitalsky.org.uk/comets/...chrones002.jpg
--

Thanks Geoff.
--
Pete Lawrence
http://www.digitalsky.org.uk
Last updated June 2006

Well done, Pete. I was going to try last night but a stubborn band of
clouds was skirting the western horizon. Maybe, I shoulda...

Pierre MK-UK

Pete Lawrence wrote:
Well part of it at least...

http://www.digitalsky.org.uk/comets/...chrones001.jpg

http://www.digitalsky.org.uk/comets/...chrones002.jpg
--
Pete
http://www.digitalsky.org.uk

On Sun, 21 Jan 2007 09:06:46 +0000, Pete Lawrence
wrote:

I doubt whether it's visible in daylight now...

I'm sure it's getting hard quickly.I saw it around noon on January 19
(the same day I imaged the tail after sunset). It wasn't hard to pick up
in binoculars, but I'm no good at estimating the magnitude of an
extended object in the day. It was definitely nowhere near as bright as
it appeared while still on the north side of the Sun. Since then, we've
had yet another snow system moving through Colorado, and by the time it
clears tomorrow or Tuesday I expect the comet will simply be too low all
day to be seen, even if it remains fairly bright. By Tuesday it will be
transiting at an altitude of only 5°.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

"Pete Lawrence" wrote in message
...
On Sun, 21 Jan 2007 02:23:58 GMT, Chris L Peterson
wrote:

The comet isn't as bright as it was earlier. It peaked about a week ago,
when it was much nearer the Sun. You can still see it in daylight with a
scope or binoculars, but I doubt you can see it naked eye.

While still quite bright, it is the length, structure, and brightness of
the tail that are making this such a striking object. The tail was
nowhere near as long when this was a northern object.

I doubt whether it's visible in daylight now. I imaged it last Sunday
(14th) and had trouble seeing it and taking the pictures. I couldn't
quite work out why as there were loads of sightings and images on the
13th (when it was cloudy for me!). Looking at the brightness estimates
the comet had dropped by approximately 2 mags from -6 to -4, making it
much harder to pick out. Look for daylight images of the comet and
you'll see loads on the 13th but very few on the 14th. Here's mine...

http://www.digitalsky.org.uk/comets/...t-daylight.jpg

The last magnitude estimate I saw for this comet was -1.5 so I think a
daylight sighting would be very difficult indeed!

Even if you could see it in daylight, visibility also depends on
location. If you live anywhere above approximately 45N the comet's
head doesn't pop up above the horizon at any time of the day.

Thanks for all that, folks. So I was probably correct with its location, was
I? It's just not bright enough now. Bummers. I did manage a quick look at it
before it nipped south of the equator, between layers of thin cloud, but
couldn't get a decent photo unfortunately. Oh for a nice total eclipse....

ally
ally