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(meteorobs) June 16 Observations



Gee, it's been so long since I did one of these I almost forgot how!

Seriously, I was out for 3.5 hours this morning at the Pine Valley
Viewpoint. The sky was beautiful tonight plus there was a soft warm wind
trickling down the mountainslopes. The major project of the night was to
compare activity from the June Lyrids verses the Xi Draconids, a shower
discovered three years ago and in need of verification. The first hour
was quite slow with only three meteors seen. Two of the three were of
zero magnitude so the show was impressive despite the low counts. Rates
picked up during the second hour with five sporadics, a Sagittarid (a
long way from home!), plus a short Xi Draconid that appeared half way
between the radiant and Polaris heading toward the northern horizon. It
extended backwards it passes some five degrees from the June Lyrid
radiant but the shortness of its path leads me to believe that it came
from the closer radiant.

The third hour produced six meteors, one XDR and five sporadics. This
second Xi Draconid appeared over in Cassiopeia and was the fastest XDR
of the night with a velocity of 8 degrees a second.

The last half hour produced 4 meteors in a brightening sky. Two of these
though were Xi Draconids. The third XDR of the night was only a one
degree flash that lasted just a fraction of a second. It appeared twenty
degrees from the radiant heading down the neck of Draco toward Cepheus.
Seven minutes later another Xi Draconid appeared low in the north
approaching the bowl of the Big Dipper. This one lasted quite long when
compared to the other three. At first glace it seemed too slow for an
XDR but when altitude and radiant distance are considered the resulting
velocity of 3 degrees per second is acceptable. 

Other than the first Xi Draconid seen, there was not another meteor that
could be remotely classified as a June Lyrid.

There was no single highlight of the session but there where a couple of
bright, trained meteors shooting swiftly from western Pegasus that were
impressive. It was also strange to see satellites during the entire
session with those spotted early in the session being limited to the
area below Polaris. I may have even witnessed an Iridium flare in the
northwest that was unexpected.

It was good to get back out under the stars and to see some old friends
again! 

June 16, 1999

0810-0910 UT  0.98   6.44   0 JLY   0 SAG   0 XDR   3 SPO   3 TOTAL
0910-1010 UT  0.95   6.37   0 JLY   1 SAG   1 XDR   5 SPO   7 TOTAL
1010-1110 UT  0.96   6.22   0 JLY   0 SAG   1 XDR   5 SPO   6 TOTAL
1110-1140 UT  0.48   5.69   0 JLY   0 SAG   2 XDR   2 SPO   4 TOTAL

TOTALS:       3.37   6.25   0 JLY   1 SAG   4 XDR  15 SPO  20 TOTAL

The first column is the period watched in Universal Time (PDT + 7
hours). The second column is the percent of an hour actually spent
watching the sky during this period. Time is lost for breaks, plotting,
and data entry. The third column is the average limiting magnitude
during each period with a minimum of 6 estimates. The last several
columns list the activity seen during each period.

I was facing north at an altitude of 70 degrees. No breaks were
taken during this session. JLY = June Lyrid, SAG = Sagittarid, XDR = Xi
Draconid, and SPO = SPORADIC (random activity).

Beginning Temperature/Relative Humidity:   66 F (19 C)  9%
Ending Temperature/Relative Humidity:      64 F (18 C)  7%

Yes, it was very dry which bothered my eyes at times. Every movement
also
produced sparks from the blanket as a result of the static electricity.

MAGNITUDES:

SAG   +4  (1)  AVERAGE  +4.00

XDR   +2  (2)  +3  (1)  +4  (1)  AVERAGE  +2.75

SPO   -1  (1)  0  (2) +1  (1) +2 (4)  +3 (3)  +4  (2)  +5  (2)
                                                          AVERAGE +2.33

Bob Lunsford

San Diego, CA  USA
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