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Re: (meteorobs) WG-PACM Alert: Beta Cygnids Nov. 1-8




>>George
Definitely none of the meteors I listed as Beta-Cygnids were Taurids.   Not
one of them moved from the direction of  Taurus which was just rising behind
me.   All the objects from the Taurus area appeared over my head and were
quite fast.   I say "from the Taurus area" because I could not be sure that
is exactly where they were coming from as that area was behind me.  <<

Ron, I have no argument here about any of your listed beta-Cygnids not being
Taurids. I trust you alignment in this discussion. It was just a suggestion
since the Taurids are active at this time of year. At this time of the night,
there will be sporadics that have apparent Slow to Moderate speeds as well. 

Ron>>The
Beta-cygnids that I listed were all quite short and I saw the biginning and
end of them and they all started within the Summer Triangle.  The 2:30 one
started within one degree of Alberio and ended  about halfway to the line
joining Vega and Deneb and would have crossed that line about one third of
the way from Vega.  <<

This meteor seems to have a path length that's too long to come from a
radiant near Albireo.

 Ron>>The 3:45 and 3:54 ones started to the left and a little
higher (dec) than Alberio and both crossed the Altair-Vega  boundary about
one third distance from Altair.  They were both about magnitude 2.   The
first I listed as slow and the second as moderate because it was a little
faster,  but technically it may be considered slow also. <<

These two meteors also seem to have too long of a path length to come from a
radiant near Albireo.

Ron>> The 4:05 and 4:11
ones both started at a higher declination than, and to the left of Alberio
and moved to the left towards, and above, Altair. <<

These two meteors I can't tell by your description as to about how long their
path lengths were....thus can't determine a personal judgement based on path
length. However, your speed judgement for a meteor that's suppose to appear
Very Slow would be very difficult to mistake as meteors with "moderate" speed
as you have indicated. It's far easier to justify the appearance of a meteor
that suppose to have moderate entry speeds to appear Very Slow than the other
way round. Based on your apparent speeds, I wouldn't consider either of these
two to be beta-Cygnids.

Ron>> The 5:12 one passed very
close to Deneb. <<

You show this meteor as being Fast. For the same reason as the two that
occurred at 4:05 and 4:11, I would disqualify it as a Very Slow speed
beta-Cygnid. 

  Ron>>These last three were very dim and short making judgement
of speed and color a little difficult.   But as I said before, I saw the
beginning and end of all six of these objects, and by continuing their line
of motion back to their origin, all six objects crossed at in an area very
close to RA 19d 50m,  Dec 30d.   Does this tally with where the Beta-Cygnid
radiant is?<<

The two listed possible radiants for a beta-cygnid radiant based on
Jenniskens Newsletter were:  RA: 19h42, Dec +31.3 and RA: 19h27, Dec +28. I
mainly was looking at the radiant of 19h42 +31.3. But I don't think the other
radiant would be helpful in declaring that these 6 meteors were beta-Cygnids.

Ron>>In closing I would stress that the speed of these objects may be open to
interpretation,   the origin and direction is not.<<

Ron, for meteors with entry velocities of Slow, Medium and Fast, I would
agree that they are open for interpretation. However, a meteor entry Velocity
of Very Slow (Which 17km/s would be classed at), they would be so obviously
different with their Sooooo Slooow speed, that it would be difficult to
mistaken as having Moderate or Fast speeds.  As for Origin and direction...no
argument there. Alignment is one of the 3 major criteria for shower
membership determinations. However, their path lengths would be arguable if
being so long and not being fireballs that close to the proposed radiants.
Thus, if a meteor cannot reasonably pass all three criteria(Alignment, path
lengths and speed), then they can't be counted as a shower member from a
given radiant. 
George Zay