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Re: (meteorobs) Aries-Triangulids
In a message dated 98-09-14 14:25:45 EDT, you write:
GeoZay>Looking at my plots for the sporadics, I can probably close my eyes
and pick any spot at random and find 1 to 4 meteors appearing to radiate from
it.
Gliba>>Nonsense. One to three meteors maybe, but not four or more. The speed
and path length must also be correct. <<
Yes to be a meteor shower radiant you would have to consider speed and path
length. But to appear radiating from it all you need is alignment. Out of 47
plotted meteors...yes 4 or more could have chance alignments...even with
proper speeds and path lengths. The odds are less as the intersections
increase. I read somewhere that to be suspicious of "radiants" when your plot
shows 3 intersections out of 25 plotted meteors. Last night I plotted 47
meteors. Speed and path lengths are considered with all my plots for shower
determination.
Gliba>>It is interesting to note that NONE of
the meteors you saw chance aligned with an A-T radiant had the correct speed.
Chance would have SOME be correct. <<
I indicated one had an alignment for both kronk and sleeter and it had
somewhat the correct speed as posted in kronks' 1993 IMO article about this. I
said it was Slow in speed as kronk indicated that the meteor speeds were Slow
to Medium like the Aquarids and Capricornids. These showers are what I would
classify as Very Slow to Slow. Not all meteors in an observing night will have
such slow speeds and I don't see too many that have apparent velocities in the
neighborhood of 16-23 km/s anyhow. If all my plotted meteors had such slow
speeds, then there probably will be more that would have the correct speed and
alignment as well. It would be quite extraordinary to have a night with
nothing but Very Slow meteors without a shower. Also not all points on my
charts will have multiple alignments with proper speed and path lengths for
the number of meteors I've plotted. It so happens that only two of the
mentioned "radiant" locations had a single meteor that barely fits the bill as
a possible candidate.
Gliba>>You are trying too hard to prove you are
correct. Chance means all possibilities.<<
There's no big effort If the meteors don't line up and fit the other
prerequisites for shower determination. Anything is possible...but from what
I've so far observed, there appears to be three chances for an Aries-
Triangulum shower...Fat, Slim and None. I know it would be a great thrill for
you to have a "discovery" under your belt...but I haven't seen any signs of it
yet. I plot as I see them and judge from that.
GeoZay>...............One such spot tonight was 5 meteors appearing to
radiate from
>the "kids" in Auriga not too far from Capella. These were all Very Fast in
>speed.<<
Gliba>>These were obviously Delta Aurigids! That radiant is only about 10
degrees
away, and errors in plotting could easily put that radiant there. <<
No these weren't obviously delta Aurigids. Granted a couple could have outside
chances of being delta Aurigids...but two left trains which made them easy to
align up on. I know at least one, Bob and I talked about as to not coming from
the delta aurigid radiant, but near the kids. It had a 2 second train. The
other with a train traversed thru the radiant with too high of a speed and
relatively long path length for it's location to the delta aurigid radiant.
But it would be appropriate if a "radiant" was in the kids. For last night,
the delta aurigid radiant is still in Perseus about 13 degrees from the kids.
Gliba>>Bad example.
In fact, the stars Delta Aurigae is right next to the kids!<<
I looked hard for any delta Aurigae stars next to the kids...but the delta
aurigae stars that I'm familiar with are about 13 degrees away roughly to the
north of Capella.
George Zay