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re: (meteorobs) Radiant Lists
Bob, you raise a few points a newbie a can comment on.First, I don't know
if controversy is the right word. I'll stick with discussion. That is after
all why Lew started this gabfest!!
My curiousity is certainly piqued. Before observing, I use the lists I have
managed to obtain for minor radiants only for determining which atlas BRNO
charts to use, and to help me select a field of view .
After observations are completed, I then pull out my new handy dandy day by
day listing of radiants that I have been able to obtain so far for placing
on the plotting map. Having just received the ALPO newsletter (PS thanx) I
will now attempt to incorporate them into my radiant database. For these
low activity showers, it would seem to me that plotting offers the only
opportunity for inexperienced observers to document showers that hover just
above sporadic background. Have you observed long enough that you can say
with some confidence that you can identify them? (If I recall correctly,
when you and George observe together, he plots, and you do nots:-). As a
new guy, I definatly could not...I still have to conciously think about
what info I have to speak into my recorder while I mentally fix the path,
fumble around for charts, etc. I'll have to see what it's like when I've
had a decade or two of practice :-)
The other factor I think should be mentioned for people to consider is
that showers are Variable/periodic/ and evolve over time. The NAMN article
(frome Bone?) describing shower evolution, as well as Gary Kronks
descriptions show that showers change over yearly, decadal, and millenial
time scales, so todays list is not necessarily tomorrows. That is why we
observe, isn't it?
The other quickie question is you mentioned Cook's list. Who was (or is)
he? When was this list published, and in what? just more information to
throw into the brain trough. Thanx, wayne
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Original Text
>From LUNRO.IMO.USA@prodigydot com (MR ROBERT D LUNSFORD), on 6/5/96 1:50 PM:
To: <meteorobs@latradedot com>
-- [ From: Robert Lunsford * EMC.Ver #2.10P ] --
It seems that the June Lyrids has started a slight controversy as to
the validity of radiants not on the IMO list. There is no doubt that
the current IMO (and NAMN) lists contain only showers that are easily
distinguished by the visual observer. Novice observers should use this
list as their guide to observing shower meteors.
Radiants removed from this list have been shown to have such a low
activity profile as to be difficult to visually distinguish from the
sporadic background. This does not mean that they do not exist. When I
started to observe meteors, Cook's list was the best available. And yes,
the June Lyrids were on that list. I used this list faithfully until
the IMO came on into the scene in 1988. I have years of data on showers
now removed from current lists. Does this mean I cannot watch for
activity from these radiants? Certainly not, and as Mark Davis
explained in his last message, the IMO will still accept data on these
showers as long as they are first listed as sporadics, and then
separated into their individual categories.
There are several newcomers that are eager to observe. So far this year
only the Lyrids have wetted their appetite for observing and weather
did not cooperate for all of them. Offering the June Lyrids as a target
shower is not a good idea. Novice meteor observers will tend to
overestimate the activity from radiants such as these. Lord knows I did
it back in the 70's when called upon to observe the Upsilon Pegasids.
I am not saying that these observers should stay in bed in mid-June,
just be very careful and list each June Lyrid as a sporadic with a
notation that it is a possible JLY. Also try to give as much detail
about each meteor in question as possible. This will help determine the
possible association with this shower.
Bob Lunsford
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