Astroblog: Occultation of the Pleiades, September 22-23

Monday, September 19, 2005

Occultation of the Pleiades, September 22-23

Image created in Stellarium.
In Australia on the 22nd of September, from around roughly 11.30 pm, until around roughly 2.30 am the beautiful Pleiades cluster will be occulted by the waning Moon. Several stars will be covered and revealed by the Moon. This will be a rather beautiful sight, the very first thing I saw when I set up my very first telescope was an occultation of the Pleiades (totally by accident, I had just trained it on the Moon to see what I could see, and I saw an occultation, I was blown away). It will be best appreciated with binoculars or a small telescope. This event will also be seen in New Zealand, New guinea, Indonesia, parts of Malaysia and Singapore. For detailed contact times see the Southern Skywatch Occultation Section.

If you have Stellarium and want to see what the occultation will look like from your site, try this script (my second Stellarium Script) after editing it for your local circumstances. Copy the section below into a text editor, change it to your latitude and longitude and save it as Oz_Pleiades_Sep22.sts in the /data/scripts directory of Stellarium. Northern Hemispherians should keep the values to see what the occultation looks like from Adelaide.


# Oz_Pleiades-Sep22.sts
# Occultation of the Pleiades, Adelaide, 22-23 Sept 2005
# Copy to Stellarium/data/scripts
# press M to activate text mode, scroll down to scripts
# use arrow key to select script
clear state natural
# set to your local latitude, occultation visible
# Australia, New Zealand, Indonesia etc.
moveto lat -34.92 lon 138.58 duration 1
# Set to appropriate local time as per skywatch page
date local 2005:09:22T23:21:24
select planet Moon pointer off
flag star_names on
flag moon_scaled off
flag cardinal_points on
zoom auto in
wait duration 1
# Shows you what your local horizon will look like
zoom fov 60
wait duration 10
# Now look at the Moon cloe up
zoom auto in
wait duration 2
set max_mag_star_name 4.0
timerate rate 200
wait duration 70
timerate rate 1
zoom fov 60
set max_mag_star_name 1.5
wait duration 5
# Tidy up
clear state natural
date load current
flag star_names on
flag cardinal_points on
flag moon_scaled on
script action end

# posted by Ian Musgrave @ 9:42 pm

Comments:

Ian, I tried the script but found that I was looking at the ground during daytime. Stellarium did change my longitude and latitude, but the time it was using seems to be the time from your script converted to my local time here in the UK.

I fixed the problem by altering your time to 2005:09:22T14:51:24 - the time in the UK (currently UTC+1) when it is 2005:09:22T23:21:24 in Adelaide (UTC+9.5 hours).

It was a nice script although the Moon kept flickering. In fact Stellarium always seems to do that to objects that are focussed on. I wonder if there is a fix for that...

P.S. Thanks for pointing out version 0.7.1.

# posted by

Anonymous : 5:18 am

Yeah, I used date local instead of date utc (I thought I was being clever at the time DUH!). I have cleared that up, and used a better way to slew to the selected object that isn't as jerky (and some associated cleanup). The new file can be found here.

The flickering image is a problem for me as well, I've asked on the Forum, so we might get an answer.

Stellarium scripts are great

# posted by

Ian Musgrave : 11:02 pm

How long before the scripts will allow us to play audio (MP3) descriptions at the same time?

I'll play with the rest of your scripts in a couple of weeks time. Must dash....

# posted by

Anonymous : 12:41 am

The scripts allow us to play several formats including WAV, have to check if it includes MP3 (likeI said, they need better documentation).

Also some text output would be great That is coming in a further release.

Sounds like the thesis is hotting up then.

# posted by

Ian Musgrave : 7:47 am

Yes. Arrghghh.

# posted by

Anonymous : 10:16 pm