Sky at Night Sun night

This has been mentioned before on this newsgroup but just in case you
forget - it's on tonight. Look out for the spectroscope from hell,
assuming it's been kept in). It genuinely did work in the end but it
wasn't the easiest of instruments. Cost a fortune to put together too
;-)
--
Pete
http://www.digitalsky.org.uk

"Pete Lawrence" wrote in message
news
This has been mentioned before on this newsgroup but just in case you
forget - it's on tonight.

Its good to see this kind of material given such prominence on the BBC. Its
been too long. They've had some superb documentaries and science programmes
on BBC2 and BBC4 over the last few months.

I've always been interested in space, science, technology and their impacts
upon our lives. These programmes are helping to fill gaps in my knowledge.

Enjoyed the show last week about the moon. I realise many people ask about
viewing the moon landers but I'm sure I read of some plans to test optical
systems by imaging the craft from lunar orbit. Did I imagine that or is it
still on the cards?

Also, another off the wall question.... I was reading about the
supernova/unusual explosion a week or two back, it got me thinking: how
close would such an event need to be in order to be seen on earth (in our
light polluted cities) by the naked eye. Would we ever see a very close one
during they daytime?

Odd question, I know but I remember reading about people in China who
documented comets and other space objects visible during the daytime.

Carl

On Mon, 6 Mar 2006 20:19:54 +0000, in uk.sci.astronomy , Mike Williams
wrote:

Wasn't it carl who wrote:

Also, another off the wall question.... I was reading about the
supernova/unusual explosion a week or two back, it got me thinking: how
close would such an event need to be in order to be seen on earth (in our
light polluted cities) by the naked eye. Would we ever see a very close one
during they daytime?

The guys who saw the crab supernova in the year 1054 reported that it
rivalled Venus in brightness and remained visible in daylight for 21
days. That one was at a distance of 6300 light years.

And for the record, we would indeed see a very close one, but only for
a short time, as the gamma radiation would probably kill us all
quickly.... :-)
Mark McIntyre
--

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"carl" wrote in message
...

"Pete Lawrence" wrote in message
news
This has been mentioned before on this newsgroup but just in case you
forget - it's on tonight.

Its good to see this kind of material given such prominence on the BBC.
Its
been too long. They've had some superb documentaries and science
programmes
on BBC2 and BBC4 over the last few months.

I've always been interested in space, science, technology and their
impacts
upon our lives. These programmes are helping to fill gaps in my knowledge.

Enjoyed the show last week about the moon. I realise many people ask about
viewing the moon landers but I'm sure I read of some plans to test optical
systems by imaging the craft from lunar orbit. Did I imagine that or is it
still on the cards?

Also, another off the wall question.... I was reading about the
supernova/unusual explosion a week or two back, it got me thinking: how
close would such an event need to be in order to be seen on earth (in our
light polluted cities) by the naked eye. Would we ever see a very close
one
during they daytime?

Odd question, I know but I remember reading about people in China who
documented comets and other space objects visible during the daytime.

Carl



S Andromedae 1885 reached 6th mag. This was a supernova in the Andromeda
Galaxy M31, distance 2.2 MLY.

And of course the 1987A supernova in the LMC reached about mag 2-3.

The 1054 AD Crab Nebula SN was seen in the daytime for a few weeks, and
Tycho's supernova of 1572 (year?) was brighter than Venus and I recall that
accounts said it was visible in the daytime. These were in our own galaxy.

--
Mike Dworetsky

(Remove "pants" spamblock to send e-mail)

On Tue, 7 Mar 2006 14:53:38 -0000, "Robin Leadbeater"
wrote:


"Pete Lawrence" wrote in message
news
This has been mentioned before on this newsgroup but just in case you
forget - it's on tonight. Look out for the spectroscope from hell,
assuming it's been kept in). It genuinely did work in the end but it
wasn't the easiest of instruments. Cost a fortune to put together too
;-)


Just watched it Pete,

I loved the "Blue Peter" science. Just my style. I assume the nice spectrum
showing the Ca, He and H lines was taken using your spectroscope? ;-)

It was very tricky to get the view just right but yes is was possible
to see some absorption lines with it. Biggest problem was that it was
very cold and the screwdriver kept slipping through the tape at the
back of the bit of CD used as a grating. Adjusting the tape invariably
pulled the silver off the back of the disk fragment.

The circular spectrum inside Patrick's dome was quite spectacular
though.
--
Pete Lawrence
http://www.digitalsky.org.uk
Last updated 4th February 2006

In message , carl
writes

"Pete Lawrence" wrote in message
news
This has been mentioned before on this newsgroup but just in case you
forget - it's on tonight.

Its good to see this kind of material given such prominence on the BBC. Its
been too long. They've had some superb documentaries and science programmes
on BBC2 and BBC4 over the last few months.

I've always been interested in space, science, technology and their impacts
upon our lives. These programmes are helping to fill gaps in my knowledge.

Enjoyed the show last week about the moon. I realise many people ask about
viewing the moon landers but I'm sure I read of some plans to test optical
systems by imaging the craft from lunar orbit. Did I imagine that or is it
still on the cards?


You didn't imagine it - it's apparently part of the scientific mission
(i.e. not just PR shots :-) of the Lunar Reconnaissance Orbiter mission
http://science.nasa.gov/headlines/y2005/11jul_lroc.htm

I thought it was a highly entertaining evening, and "The Sky at Night"
really whetted my appetite for the solar eclipse this month!
But is the speed of light really "less than 1 millimetre per second" in
the core of the Sun? I thought the photons just did a very long random
walk on their way out.

"Jonathan Silverlight"
wrote in message ...
In message , carl
writes

"Pete Lawrence" wrote in message
news
This has been mentioned before on this newsgroup but just in case you
forget - it's on tonight.

Its good to see this kind of material given such prominence on the BBC.
Its
been too long. They've had some superb documentaries and science
programmes
on BBC2 and BBC4 over the last few months.

I've always been interested in space, science, technology and their
impacts
upon our lives. These programmes are helping to fill gaps in my
knowledge.

Enjoyed the show last week about the moon. I realise many people ask
about
viewing the moon landers but I'm sure I read of some plans to test
optical
systems by imaging the craft from lunar orbit. Did I imagine that or is
it
still on the cards?


You didn't imagine it - it's apparently part of the scientific mission
(i.e. not just PR shots :-) of the Lunar Reconnaissance Orbiter mission
http://science.nasa.gov/headlines/y2005/11jul_lroc.htm

I thought it was a highly entertaining evening, and "The Sky at Night"
really whetted my appetite for the solar eclipse this month!
But is the speed of light really "less than 1 millimetre per second" in
the core of the Sun? I thought the photons just did a very long random
walk on their way out.
Keyword missing in the statement. 'Effective'.
The actual speed is reduced by the enviroment, but not by this much!...

Best Wishes

In message , Roger Hamlett
writes

"Jonathan Silverlight"
wrote in message ...

I thought it was a highly entertaining evening, and "The Sky at Night"
really whetted my appetite for the solar eclipse this month!
But is the speed of light really "less than 1 millimetre per second" in
the core of the Sun? I thought the photons just did a very long random
walk on their way out.

Keyword missing in the statement. 'Effective'.
The actual speed is reduced by the enviroment, but not by this much!...


Thanks - that's what I thought. I wonder if the random walk and the very
long time it takes light to escape inspired Bob Shaw's "Slow Glass".
Does anyone actually know the speed of light in the core? (though I'd
guess most of the radiation is hard X-rays)
If it's anything like the speed in vacuum the photons effectively travel
several thousand light years before escaping.