(meteorobs) quadrantids and more

[Norman W. McLeod III]

Weather in Florida has been very cloudy for some time, but Jan 1/2 after 
midnight cleared off.  No observing planned then.  Will have to wait and 
see if the clear spell holds long enough for the Quadrantids, then we will 
go out after 3 AM.  There is still a lot of cloudiness over the Atlantic 
headed this way.  Comfortable temperatures at least, doing about 80F day 
and mid-50's night with just enough wind to keep fog away.  Unless mostly 
clear, combined with the moon interference would make it not worth going 
out.  I saw the last two favorable returns here.  2001 didn't get up to 
full speed, only 34/hr in dark sky.  1997 was my best ever, 61/hr but with 
thick crescent moon ; bad weather almost everywhere else.


 From Bruce on upcoming Quads,
 >Of course you mean 2005.

I had that in mind, but, wouldn't you know it, I still wrote it 
wrong.  Correction was needed right away.


 >And it really doesn't have anything to do with luck.

I am aware of the moon cycles.  My intent here was in the sense of cursing 
the unfortunate, but known, circumstances, as opposed to finding out 
last-minute about some random moon-phase event.  Bruce's list of future 
moon phases for favorable American Quad maxes shows what we are facing for 
the next two decades.  Two cycles that coincide so well can keep you in a 
rut for a long time.

One of my favorite moon phase cycles allows a quick look ahead for short 
periods.  Make a list of the eight major phases : new moon, waxing 
crescent, first quarter, waxing gibbous, full moon, waning gibbous, last 
quarter, waning crescent.  Next year on the same date the moon advances 3 
phases along the list.  In 3 years it advances  1 phase (9 phases total 
which is once around the list then starting over.)  All this is approximate 
but it works quite well.  In 8 years there are 24 phase advances, or 
exactly 3 trips around the list, hence, as Bruce showed us, the phase 
repeats quite closely.  Larger numbers of bright Taurids tend to come once 
in 3 returns so there is a period of bad moon interference in those 
particular years (such as the 1980's) followed by a period of little or no 
interference.


 From Bob,
 >This is from Gary Kronk's book on Comet's and Meteor Showers. I'm not 
sure if this is still the current belief as >the Geminid rates were 
expected to fall during the 1990's and into the 21st century.

I looked at Gary's article but could not find this reference.  Will try 
again.  In the early 1980's  "Astronomy"  magazine addressed this 
issue.  That writer surmised that the period of bright Geminids that comes 
after maximum would be shifting to the middle of the display in the 1980's, 
then come before the max after 2000 or so.  At the time the article 
appeared I already had seen no evidence of this shift in progress.  To this 
day that has not occurred.  I never expected any such thing to happen 
anyway.  After the great 1996 Geminid display I didn't get to see them 
again until 2001, and there was quite a drop just in that period.


 From Kim (xy),
 >Lew, Bob, & Wayne (and Cathy!) seemed to demonstrate that I *may* not be 
able to experience a truely dark >sky like many of the rest of you.

I should have considered this before.  Kim lives in a remote part of 
Georgia well away from larger cities, so he should have easy access to dark 
skies.  There have been other people out with me, who, likewise, see much 
less than I do, a full magnitude and more poorer.  They see only LM 6.0 as 
opposed to my LM 7.3 in the same sky.  The same applies to telescope 
usage.  An active galaxy observer around here in the late 1980's would show 
me a faint galaxy he was studying, and almost every time I would indicate 2 
or 3 additional fainter galaxies close by the original that he wasn't seeing.


Richard said,
 >observed under the same conditions, we would see different meteor 
rates.  Meteor observing is at least as >much visuo-perception as it is 
limiting magnitude.

Very true.  The pithy expression from Bill Gates is that meteor rates 
depend on two factors : skies and eyes.  I had almost no direct experience 
with the latter until Gates joined us in 1973.  It wasn't much of an issue 
in the early days since no one was radically different from the norm.


Malcolm said,
 >Kim.  Do you record the DCV?

I did, for about 6000 meteors in 1974-75.  The value wasn't changing so I 
decided there was enough data to discontinue recording.  My DCV (Distance 
from Central Vision) is all of 6 degrees.  Gates was 25 degrees, for rates 
almost 4 times higher.  Definitely a correlation.  For DCV, record how far 
from your central vision you first detect each meteor seen.  Accuracy to 
the nearest 10 degrees is plenty sufficient.  If the DCV is 5 degrees or 
less, call it 0.  Make a table of DCV vs meteor magnitude.  I suppose DCV 
vs meteor speed could be done if the data is available, but magnitude 
should be the primary indicator of whether you are going to see a meteor or 
not.


 From Bob,
 >... be related to Norman's "December Leonids" as the radiant would
 >have been near the "sickle" of Leo last week. By the way I was looking for
 >any December Leonids during the Geminids and any possible members were few
 >and far between. Most of those candidates were just too swift...

I noted only 2 December Leonids this year myself.  Perseid-speed meteors 
coming from the top of Leo's sickle during the first half of 
December.  This is something Florida observers started noting in 1972, and 
Bill Gates saw a few himself.  I have never plotted them, however, and do 
not have a precise radiant.


 From Javor,
 >The sporadic numbers were quite low despite respectable limiting
 >magnitude, probably because I was not well rested.

That was sporadic rates of 8 and 11 at rough local hours 11 PM to 1 
AM.  Seems like very healthy numbers to me, at least twice what I would 
expect for those hours.  Perception again.


On the police matter, I notified the campus cops at Florida State in the 
years 1964-68 when I went out observing.  Was using an athletic 
field.  Once in a while one of them came by, and they knew what was going 
on.  Always had a pleasant moment with them.  When using a public place for 
observing, others should follow suit.  In my time here, only one sheriff 
came by, when I had a telescope out.  He only saw me because I was visible 
from the highway.  It's a different deal when you have to make an unplanned 
trip to another location because of weather or other reasons.  Povenmire 
always notified the locals when he had groups going to occultation graze lines.

That catches me up on recent business.  Need to get this out before I 
disappear into the tax office for the next 3+ months.

Norman



Norman W. McLeod III
Staff Advisor
American Meteor Society

Fort Myers, Florida
nmcleod at peganet.com