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(meteorobs) Re: Problems...
Karl and All,
As for the Alpha Capricornid and Sagittarid problem, I agree that these two
sources will be difficult to distinguish. At this time in early July, the
antihelion would be the more active radiant so any meteor from that region
is most likely a member of the antihelion radiant (Sagittarids). As the
month progresses the Alpha Caps equal the strength of the antihelions and
can even surpass it during the last week of the month. Since they are
currently twelve degrees apart it may be possible to distinguish between the
two by using a dark string (such as a shoelace) out in the field. Place the
string over the path of each meteor you see and then trace the path
backwards. If it passes closer to one radiant than the other then assign it
to the closer radiant. If it passes through both radiants you can use the
angular velocity to help you. If the meteor travels ten degrees per second
then chances are it belongs to the radiant that is furthest away. If the
meteor travels closer to five degrees per second then chances are it belongs
to the closest radiant.
As you can see, in order to distinguish between these two sources, you need
to know the location of each radiant on the nights you observe. The radiant
drift for the Alpha Caps is 0.9 degrees eastward in right ascension and 0.3
degrees northward in declination each night. The radiant drift for the
antihelion source is 1.0 degrees eastward in right ascension and 0.2 degrees
northward in declination each night. The positions listed in my weekly
outlooks are exact for Saturday night/Sunday morning July 5/6.
I hope this helps!
Bob
----- Original Message -----
From: "Karl Antier" <karl.antier@wanadoo.fr>
To: <meteorobs@atmob.org>
Sent: Wednesday, July 02, 2003 10:05 AM
Subject: (meteorobs) Problems...
> Hi all !
>
> After a long period of non-observing, I'm now going to come back in the
> great team of meteor observers... But as I was preparing my first new
> sessions, I faced two major problems :
> - the first one consisted in the way to make the distinction between
> alpha-Capricornids and Sagittarids. Their radiants are currently very
> close together, and as I leave in Western France ( 1°34'1.2"W ;
> 46°40'1.2"N ), their aren't very elevated, and, if I observe at an
> elevation of 50-70°, meteors coming from both of these streams will
> appear parallel. And the velocity of these two sources are also similar
> : 25km/s and 30 km/s, the difference seems for me too small to allow a
> disinction. Can someone help me and tell me what's the best solution ?
> - the second one is that during my 2 years break, I got the surprise to
> get a pair of glasses, for astigmatism and short-sighting... Have I
> better keeping them while observing, even if my field of view will be
> restricted, or must I throw them away, even if my lm might be not as
> high as before ? The correction is not very very important, ( it must be
> 6/10 and 8/10, or something like that ).
>
> Thanks in advance for your answers !
>
> Clear skies !
> Karl.
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