(meteorobs) quadrantids and more

[Bruce McCurdy]

Norman wrote:

>  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.

    Just trying to help. :) Effectively the leap year *begins* on Feburary
29, and everything is out of kilter by one day for the immediately following
calendar year through February 28 of Leap Year Plus One. Thus in the current
instance, the Quadrantid maximum leaps forward from the 4th to the 3rd not
in January 2004 but in January 2005. So in that sense one could argue the
leap year is still ongoing, and it's certainly easy to make a mistake with
the year number. It would be a lot simpler if they declared a 'January 0'
every fourth year, then all the adjustments would be done in the same (true)
calendar year. However, as  Rita Mae Brown famously said, 'If the world were
a logical place, men would ride side saddle.'

>>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.

    Well the first quarter moon in 2009, 2017, 2025 etc. is very gradually
'waning', and in any event it has long since set by the time of the pre-dawn
maximum, so the situation is not a total loss. And here in the Great White
North with our almost 17-hour nights, the Quads maximum is accessible to
some extent three years out of four. I had a very nice session two years ago
tonight during the evening hours, when the radiant transited the *northern*
meridian about 14 degrees up, around 9 p.m. local time. Rates were reduced
of course, but it was still a decent show.

> 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.

    That's a nice quick'n'dirty method, effectively 12 3/8 lunations per
calendar year. I just use a mantissa of 11 days, but that's pretty much a
phase and a half as you point out. The 8-year cycle is not quite exact of
course, it's off by about a day and a half, but that amounts to a shift of
only one lunar phase during an observing life of 40 years.

    A further consideration at this time of year which some of our more
tropical observers might not be aware is snow cover, especially if it's
fresh. The high reflectivity of the ground curtails limiting magnitude to
some extent even at new moon, and exacerbates the problem of moonlight
significantly.

    Alas, weather here in Edmonton looks decidedly unpromising for tonight's
Quads.The temp continues to hover around minus 22° C.with a wind chill of
about minus 32°, but the bigger concern is the overcast which will likely
persist though tonight. I will monitor the Quads by radio, but if by chance
there's a clear break at 3 or 4 a.m. I have my 9 layers ready to go. Wish me
'luck'.  :)

    regards, Bruce