Congratulations Chris Peterson

Sky & Telescope's weekly astronomy bulletin just came out and
Chris Peterson's work on the recent Pluto Occultation made the grade.

Here's the story:

http://skytonight.com/news

Congratulations Chris..great work!

"Ed" wrote

Sky & Telescope's weekly astronomy bulletin just came out and
Chris Peterson's work on the recent Pluto Occultation made the grade.

Here's the story:

http://skytonight.com/news

Where? I can't find it on that page. Please provide a *specific* link.

Howard Lester wrote:

"Ed" wrote

Sky & Telescope's weekly astronomy bulletin just came out and
Chris Peterson's work on the recent Pluto Occultation made the grade.

Here's the story:

http://skytonight.com/news

Where? I can't find it on that page. Please provide a *specific* link.

Hi Howard,

Here you go:

http://skytonight.com/observing/obje...on_Report.html

Clear Dark Steady Skies,
Dave Jessie

On Fri, 30 Mar 2007 08:19:43 -0700, "Howard Lester"
wrote:

Sky & Telescope's weekly astronomy bulletin just came out and
Chris Peterson's work on the recent Pluto Occultation made the grade.

Here's the story:

http://skytonight.com/news

Where? I can't find it on that page. Please provide a *specific* link.

It's not there anymore (news marches on...). Here's an archive link:
http://skytonight.com/observing/home...on_Report.html .

One comment: when Dennis di Cicco wrote that piece, I was still assuming
the path was farther south, and fitting my data to a flat bottomed model
(that is, the assumption was that the occultation was total). We now
know the path was farther north, and was probably just on the edge of
totality from my location. So the current fit shown at
http://www.cloudbait.com/science/pluto2007.html more accurately shows
the profile of the occultation, with the entire event dominated by the
effects of Pluto's atmosphere.

_________________________________________________

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

"Chris L Peterson" wrote

One comment: when Dennis di Cicco wrote that piece, I was still assuming
the path was farther south, and fitting my data to a flat bottomed model
(that is, the assumption was that the occultation was total). We now
know the path was farther north, and was probably just on the edge of
totality from my location. So the current fit shown at
http://www.cloudbait.com/science/pluto2007.html more accurately shows
the profile of the occultation, with the entire event dominated by the
effects of Pluto's atmosphere.

I wonder if the 2.3-m IR observatory in Laramie, Wyoming saw it. ? The MMT
got it here in southern Arizona, but to what extent I don't know - I haven't
asked!

On Fri, 30 Mar 2007 08:56:04 -0700, "Howard Lester"
wrote:

I wonder if the 2.3-m IR observatory in Laramie, Wyoming saw it. ? The MMT
got it here in southern Arizona, but to what extent I don't know - I haven't
asked!

The weather across the southwest was uncharacteristically bad, and a
number of sites were clouded out. But the real problem was that all the
big scopes from Southern California to Texas were expected to be much
closer to the central path. In the end, they were so far south of the
path that they only caught the edge of the atmosphere. That may turn out
to be useful for refining the atmospheric model of Pluto, but it is hard
to use the data for refining Pluto's position. Have a look at the curves
at the bottom of http://calys.obspm.fr/%7Esicardy/18_march_07/index.html
for an idea of what different sites could have captured (including Mt
Hopkins).

I haven't heard that the WIRO facility in Wyoming has reported any data,
although they planned on observing the event. As far as I know, the only
site to record a total occultation was the Moore Observatory in
Washington.

_________________________________________________

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

Chris,

Congrats and kudos once again.

Ben

"Chris L Peterson" wrote

The weather across the southwest was uncharacteristically bad, and a
number of sites were clouded out. But the real problem was that all the
big scopes from Southern California to Texas were expected to be much
closer to the central path. In the end, they were so far south of the
path that they only caught the edge of the atmosphere. That may turn out
to be useful for refining the atmospheric model of Pluto, but it is hard
to use the data for refining Pluto's position.

I'm sure they all got useful data, and a "grazing" occultation giving more
time through the atmosphere might be the most useful. I should just go down
the hall and ask the astronomer who was in charge of this! Tucson had clouds
all day and into the evening, but by around 8PM the sky cleared nicely. I
didn't look to see just who got clouds.

Have a look at the curves
at the bottom of http://calys.obspm.fr/%7Esicardy/18_march_07/index.html
for an idea of what different sites could have captured (including Mt
Hopkins).

Didn't bode well for Mt. Hopkins on that chart.

I haven't heard that the WIRO facility in Wyoming has reported any data,
although they planned on observing the event. As far as I know, the only
site to record a total occultation was the Moore Observatory in
Washington.

Are you referring to their 30" on, I think, Table Mountain?

Ummm why does pluto's light change? It is passing in front of the star and
presumably blots out the star.

On Fri, 30 Mar 2007 18:42:05 GMT, "Arthur Riddick"
wrote:

Ummm why does pluto's light change? It is passing in front of the star and
presumably blots out the star.

The curve shows the combined light of the star and Pluto. The image
resolution isn't high enough to show them as separate sources. You add
magnitudes as

m = m2 - 2.5log(10^(0.4(m2-m1)) + 1)

So for m(pluto) = 14.4, and m(star) = 14.9, the sum is 13.87. For a
complete occultation, you'd see a drop from 13.87 (both objects) to 14.4
(just Pluto), or 0.53 magnitudes. That's very close to what I observed,
which suggests that the occultation was nearly total from central
Colorado.

_________________________________________________

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