Observatory Logo

From: TerryMoselaol.com
Date: Fri, 16 Jul 2004 18:01:59 EDT
Subject: Ast. occ, Lectures, ISS, Sun, Venus, Solar day:

Hi all,

1. Bright star to be occulted by asteroid, 20/21 July. The track crosses 
Ireland diagonally from NW to SE, entering at Counties Mayo & Sligo, and exiting 
at Wicklow, Wexford & E Waterford. It occurs at about 01.19 UT - that's 02.19 
   It will be a very interesting observation if you see it, and if you time 
it accurately (to the nearest second, or better - preferably to 0.2 or even 
0.1sec) you can do some real useful science! 
   The star is magnitude 6m.4, and will be occulted by 773 Irmintraud, 
magnitude 13.8, so the drop in combined brightness will be 7.4 magnitudes - in 
effect the star will totally disappear for up to 10 seconds or so! You''ll need to 
be set up about 20 mts before the event, with the star (HIP 186, RA 0h 2m 
24.167 secs, Dec +8 deg 57m 24.55 sec) clearly identified, your tracking on, your 
timing ready, stopwatch or camera timer checked against an accurate time 
source, etc. Time both disappearance & reappearance as accurately as possible. It's 
worth looking for up to 15 mts before & after the nominal time, in case there 
is a secondary occultation by a satellite of Irmintraud!
   The following details were sent to me by Tolis Christo at Armagh 
Observatory, who will co-ordinate any observations 

"Hi Terry, I don't know whether you've made any plans for the Irmintraud 
occultation on the night of the 20th July.
   We here intend to undertake a little expedition and travel to the centre 
of the track; the exact location is to be decided by the weather at the last 
minute. For a 6th mag star, I think it is worth it.
   I was wondering whether you know of any amateurs that might be willing to 
observe from within the nominal track. Check the track map at 
   If we get enough chords, we should be able to do a shape determination 
(best-fit ellipsoid) with Irish-only data.
   Thanks, Tolis."

CCD or Digital video camera observations are best, but even visual timings 
with an accurate stopwatch will be useful if they are done properly.

2. There are still tickets for the two public lectures at the RDS Concert 
Hall in Dublin 4, by two of the best-known names in modern physics/cosmology!

(1). On Monday July 19 Prof Kip Thorne will give a lecture entitled "Probing 
the Universe and Black Holes with Gravitational Waves"

(2). On Friday July 23 Prof Sir Roger Penrose will talk on "Fashion, Faith & 
Fantasy in Modern Physical Theories".

Both lectures start at 20.00, and are part of the 17th International Congress 
on General Relativity & Gravitation, being held at the RDS.  Tickets cost €
20, (€10 students), and can be booked online at  

3. The ISS continues to make a nice series of evening passes for the next 
week or so: details at 

4. The Sun has re-awakened, with some spectacular spots coming towards the 
centre of the disc. Look out for possible aurorae over the next week or so.

5. Venus is now at maximum brightness as a morning star in the dawn twilight 
- a beautiful sight for early risers!

6. Remember the next IAA "Solar Day" at Carnfunnock Country Park, near Larne, 
on 31 July. More details later.

Clear Skies,

Terry Moseley


Last Revised: 2004 July 19th
WWW contact:webmaster@arm.ac.uk
Go to HOME Page Home Page