(meteorobs) Summary: 23/24 Jun 2004, Rockport MA USA - June Bootids STILL ACTIVE?

[Lewis J. Gramer]

I had the great pleasure to observe meteors on the
public field outside Halibut Point State Park on
the coast of Cape Ann, MA USA, last night. It was
a serene evening, with an intermittent breeze off
the nearby ocean, and just the occasional mosquito.

Halibut Point skies are remarkably dark Eastward,
but I had a varying amount of moisture in the air
last night - which combined with the lingering rays
of light from the First Quarter moon as it set, to
make my LMs worse than they can probably get here.

Some details are below, but suffice to say I DID
see clear activity from the June Bootids tonight!
(All possible candidates would add up to HR=6.)

And of course this wasn't just the "I saw several
slow meteors that came out of the north" - these
were "double-blind" plots (and in fact I was not
expecting to see anything from the shower!)

All meteors were faint tonight: the highlights
were a mag. 2 Sporadic at 03:29UT, and a long,
very slow mag. 3 golden meteor (plotted as a
probable JBO) with a wake, at 03:34UT. Sigh!


Several other experienced observers have reported
sessions from last night - all with minimal or no
JBOs seen. So was I the only observer to see this
last hurrah from the 2004 JBOs last night? What
a strange chance that would be! I look forward
to hearing still more reports from 23/24 June...


METHOD:
I plotted mainly potential JBOs (plus a possible
June Lyrid - "JLY", and a few obvious Sporadics).

I approached the night with no specific idea of
where the JBO radiant should be. And the result
is a really lovely set of 9 probable candidates
(on all criteria - path, maximum length, speed),
tracing back to within less than 5 degrees of a
radiant point at 15:40 +41! (There were also 2
other candidates that were weaker based on path
alignment, and one candidate I did not plot - I
count all of these as SPORADICS below...)

Plotting errors have not yet been worked up.

15:40 +41 is a spot about 11o SE (PA=130) of the
peak night radiant - without any corrections for
Zenithal attraction. Allowing some uncertainty in
the orbit of the particles making up the potential
activity this night, that is a remarkable match!

Note that these 12 candidates were observed in a
short effective observing time - Teff=1.88 hours,
over a period of about 2.5 hours - with Limiting
Magnitude averaging close to 6.3 for the period.
(The IMO Count Areas used were 1, 7, 15 and 19.)

Complete report with Period breakdowns to follow
as soon as I can reduce my plots (and copies of
plot charts to follow to NAMN by postal mail).

But in the meantime, here's a quick summary:

------------------------------------------------------------
DATE: June 23/24 2004
BEGIN: 02:45 UT  END: 05:16 UT
OBSERVER: Lew Gramer (GRALE)
LOCATION: Lat: 42:41 N, Long: 070:38 W, Elev: 20m
          Halibut Point, Rockport MA USA
RECORDING METHOD: clipboard/ruler, 8"x11" BRNO plot charts
------------------------------------------------------------
OBSERVED SHOWERS:                 Radiant Position  Size
        JBO (June Bootids)               14:50 +47  10o
        SAG (Sagittarids)                18:40 -23  10o
        JLY (June Lyrids)                18:40 +35   5o
        SPO (Sporadics)
------------------------------------------------------------

OBSERVING PERIODS: 0 = none seen;  / = shower not observed

PERIOD(UT) CFV     Teff F    LM     JBO SAG JLY  SPO Total
0245-0516  1700+70 1.88 1.00 6.3     9   1   2   22*    34

(* - Includes some candidates which may potentially become
     JBOs on more careful examination of plots.)
------------------------

BREAKS:
03:10-03:20 UT  10.0 min
04:35-04:45 UT  10.0 min
     Dead time: 18.2 min   (15 plots X 60 s/plot  = 15.0 m)
                           (19 counts X 10 s/count = 3.2 m)
Total:          38.2 min
              = 0.64 hour
------------------------------------------------------------
CFV - Center of Field of View - direction faced
Teff - Effective observing time, minus Breaks + "dead time"
F - correction factor for obstructions/clouds (0% tonight!)
LM - naked-eye Limiting Magnitude
JBO - count of (probable) June Bootids logged
SAG - count of Sagittarids / Anthelion meteors logged
JLY - count of (probable) June Lyrids logged
SPO - count of Sporadics (non-shower meteors) logged
------------------------------------------------------------