[AZ-Observing] More Precision Science by Amateur Astronomers
- From: Sam&Anne <sam&anne@xxxxxxxxx>
- To: az-observing@xxxxxxxxxxxxx
- Date: Sat, 7 Apr 2007 21:12:48 -0700
Cool stuff being done with asteroid video timings!
It takes a telescope; about $500 worth of equipment, and then
persistence and luck to be "in the right place, at the right time."
"Limovie" is free video analysis software. After going to the link
below, click on the Limovie graph links for Feronia. ................sam
----- Original Message -----
From: "Brad Timerson"
To: <IOTAoccultations@xxxxxxxxxxxxxxx>
Sent: Thursday, April 05, 2007 11:16 PM
Subject: [IOTAoccultations] Preliminary Feronia Results
> Good morning everyone:
>
> The "very" preliminary results for the unusual Feronia event have
> been posted. Roc Fleishman and Kerry Coughlin both recorded a
> double event for a star that wasn't previously known as being double.
>
> I have never done the analysis of a "2nd star" event, so my
> presentation is, with nearly 100% certainty, inaccurate. I have
> sent all the pertinent information to Dave Herald for his review.
>
> In any event, I have posted preliminary "profiles" and the LiMovie
> graph sent to me by Roc. The two events are very easy to see.
>
> All the latest observations are at:
> http://www.asteroidoccultation.com/observations/Results/
>
> Brad Timerson
> Head Coordinator
> IOTA Asteroid Occultation Program
> North America
>
1b. Re: Preliminary Feronia Results
Posted by: "Dave Herald"
Date: Thu Apr 5, 2007 7:28 am ((PDT))
The LiMovie plot in the link below is an excellent example of a
double star event, and the
value of a limovie analysis. Firstly, by measuring the relative
changes in the brightness
change for the two components, you can determine which star is the
primary star, and the
order of the events - that is, whether the stars D/R in the order
1,2,1,2, or 1,2,2,1.
Similarly this can be correlated with eth observations from other
observers, to make sure
the events from the different sites are allocated to the same star.
Additionally, a measurement of the relative change in brightness also
allows the magnitude
difference to be determined. And given the total magnitude of the
star, you can then get
the magnitudes of the components.
In this case, the sequence of events is 2,1,2,1, with the brightness
of star '2' being
significantly less than the primary star. Unfortunately the ratio of
brightness changes at
the D and R are somewhat different - so that all I can determine is
that the magnitude
difference between the components is somewhere between 1.0 and 1.8.
When anyone records such a double star event, you should send a copy
of the limovie pot to
your regional coordinator so that it can be fully analysed.
Anyway, the analysis of the results from the two successful observers
gives the following
determination of the double star parameters for the star involved -
Hip 32525
PA 71.3 +/-1.9, Sep 0.0097" +/-0.0003", Mags 7.8 and 9.1
[And in case you run into anyone who thinks that amateurs can't do
high precision
astronomy, just reflect on the precision of this measurement of the
separation.... We are
dealing with milli-arcsec astronomy here.....]
Dave Herald
Canberra, Australia
>
>
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