sun seen from Uranus

Hello,
I was showing a friend a picture I've taken of Uranus this w-e. he was
well impressed and said "I wonder what the sun looks like seen from
there". I've been trying to find either real pictures (from voyager?) or
artist creation of what it looks like without success. The only source I
have is my Starry Night program, where you can set the observing point
to uranus, but I don't know if it's supposed to be a realistic image.
Anyone can point me to the right website?

Many thanks

Philippe

On Mon, 04 Oct 2004 10:10:10 +0100, Philippe Gautier
wrote:

Hello,
I was showing a friend a picture I've taken of Uranus this w-e. he was
well impressed and said "I wonder what the sun looks like seen from
there". I've been trying to find either real pictures (from voyager?) or
artist creation of what it looks like without success. The only source I
have is my Starry Night program, where you can set the observing point
to uranus, but I don't know if it's supposed to be a realistic image.
Anyone can point me to the right website?

Starry Night gives a pretty good approximation as to what somethings
look like from other places in the Solar System / Galaxy. In the case
of Uranus, it's depiction fails a bit in respect of the magnitude of
the scene. According to it's info window, the Sun would be 1 arcmin
across (that's approximately 1/30th the apparent diameter of the Sun
as seen from Earth) and magnitude -21.48. That's a bright dot in the
sky!

If these figures are not correct - read it to the software, not me!

Just before Venus went into transit last June, it's apparent angular
diameter was approaching 1 arcmin but it was too close to the Sun to
see it in dark skies.

At the end of April 2004 it's apparent diameter was about 0.5 arcmin.
At this time it's magnitude was about -4.5 at maximum brightness.
-21.48 is 17 magnitudes brighter or 2.5^17 times brighter than Venus
at it's brightest (that's about 6 million times brighter if my Monday
morning maths is working - unlikely ;-) ).

If the above is correct, you can tell your friend to remember what
brilliant Venus looked like in the evening sky (or indeed to get up
and see it for real in the current morning sky) and imagine what it
would look like 6 million times brighter but twice the size (or 4x the
current morning size of 15 arcsecs apparent diameter).

--
Pete Lawrence
http://www.digitalsky.org.uk

Pete Lawrence wrote:
On Mon, 04 Oct 2004 10:10:10 +0100, Philippe Gautier
wrote:


Hello,
I was showing a friend a picture I've taken of Uranus this w-e. he was
well impressed and said "I wonder what the sun looks like seen from
there". I've been trying to find either real pictures (from voyager?) or
artist creation of what it looks like without success. The only source I
have is my Starry Night program, where you can set the observing point
to uranus, but I don't know if it's supposed to be a realistic image.
Anyone can point me to the right website?


Starry Night gives a pretty good approximation as to what somethings
look like from other places in the Solar System / Galaxy. In the case
of Uranus, it's depiction fails a bit in respect of the magnitude of
the scene. According to it's info window, the Sun would be 1 arcmin
across (that's approximately 1/30th the apparent diameter of the Sun
as seen from Earth) and magnitude -21.48. That's a bright dot in the
sky!

If these figures are not correct - read it to the software, not me!

Just before Venus went into transit last June, it's apparent angular
diameter was approaching 1 arcmin but it was too close to the Sun to
see it in dark skies.

At the end of April 2004 it's apparent diameter was about 0.5 arcmin.
At this time it's magnitude was about -4.5 at maximum brightness.
-21.48 is 17 magnitudes brighter or 2.5^17 times brighter than Venus
at it's brightest (that's about 6 million times brighter if my Monday
morning maths is working - unlikely ;-) ).

If the above is correct, you can tell your friend to remember what
brilliant Venus looked like in the evening sky (or indeed to get up
and see it for real in the current morning sky) and imagine what it
would look like 6 million times brighter but twice the size (or 4x the
current morning size of 15 arcsecs apparent diameter).


Waouw, thanks for all the info, Pete!

Philippe

Pete Lawrence wrote:

Starry Night gives a pretty good approximation as to what somethings
look like from other places in the Solar System / Galaxy. In the case
of Uranus, it's depiction fails a bit in respect of the magnitude of
the scene. According to it's info window, the Sun would be 1 arcmin
across (that's approximately 1/30th the apparent diameter of the Sun
as seen from Earth) and magnitude -21.48. That's a bright dot in the
sky!

If these figures are not correct - read it to the software, not me!

Starry Night may not be so wrong - my version gives Sun's magnitude as
-20.38 from Uranus and -26.90 from Earth - that's a difference of 6.5
magnitudes 19 au further away from the Sun than Earth. It should be 19
squared times dimmer = 361.

6.5 magnitudes =100*2.51*(something or other for the half and I bet
it's not far off 1.43) making a difference of 361.

Anyway I've got a pair of eclipse glasses for your trip to Uranus.

It seems odd - but high noon on Uranus is still going to be pretty
dark.

--
Martin

Martin Frey wrote:

It seems odd - but high noon on Uranus is still going to be pretty
dark.

I'm sure I'm going to made to regret posting that.

--
Martin

On Mon, 04 Oct 2004 13:38:52 +0100, Martin Frey
wrote:

Pete Lawrence wrote:

It seems odd - but high noon on Uranus is still going to be pretty
dark.

Often the way in the valleys ;-)
--
Pete Lawrence
http://www.digitalsky.org.uk

In message , Martin Frey
writes
Martin Frey wrote:

It seems odd - but high noon on Uranus is still going to be pretty
dark.

I'm sure I'm going to made to regret posting that.


I'll get in first with a remark about it being dark where the sun
doesn't shine, but go on to say that the Voyager team had to do some
clever programming to get the amazing pictures they did. Sadly, the
encounter was overshadowed by events closer to home.
--
What have they got to hide? Release the ESA Beagle 2 report.
Remove spam and invalid from address to reply.

Pete Lawrence wrote:

On Mon, 04 Oct 2004 13:38:52 +0100, Martin Frey
wrote:

It seems odd - but high noon on Uranus is still going to be pretty
dark.

Often the way in the valleys ;-)

And there was I, on the point of congratulating you on the piccy on
extended Sky at Night - well I won't now, so there.

Enjoyed the prog - the extra 10 mins well worthwhile.

--
Martin

On Mon, 04 Oct 2004 21:05:06 +0100, Martin Frey
wrote:

Pete Lawrence wrote:

On Mon, 04 Oct 2004 13:38:52 +0100, Martin Frey
wrote:

It seems odd - but high noon on Uranus is still going to be pretty
dark.

Often the way in the valleys ;-)

And there was I, on the point of congratulating you on the piccy on
extended Sky at Night - well I won't now, so there.

Enjoyed the prog - the extra 10 mins well worthwhile.

I was just in the process of writing to Anthony Ayiomamitis to ask him
for permission to use a couple of his images in a local presentation
to Selsey Camera Club when I looked at the telly and saw a familiar
M15, then a familiar M33 then Anthony's lunar eclipse montage!

Almost ranks along the same weirdness of my office cleanout last week.
I had just thrown out some files relating to a project that ended for
me 6 years ago when a phone call occurred. Yep, it was the same
client! Synchronicity in action!

--
Pete Lawrence
http://www.pbl33.co.uk
Most recent images http://www.pbl33.fast24.co.uk/recent_images.html

Philippe Gautier wrote:
Hello,
I was showing a friend a picture I've taken of Uranus this w-e. he was
well impressed and said "I wonder what the sun looks like seen from
there". I've been trying to find either real pictures (from voyager?) or
artist creation of what it looks like without success. The only source I
have is my Starry Night program, where you can set the observing point
to uranus, but I don't know if it's supposed to be a realistic image.
Anyone can point me to the right website?

Many thanks

Philippe

I quite like the Celestia software, not only can you move freely through
the solar system, you can move to other stars, and even out of the
galaxy. Not sure how accurate it is (although if you get the NASA data,
I'm guessing it's pretty good), but either way, it's fun, and free.

Larry