Saturday, December 26, 2009
Wednesday, December 23, 2009
Thursday, December 17, 2009
A Poem - What if we threw a (star) party and nobody came?
What if we threw a (star) party and nobody came?
It was the night of the Geminids,
In the year two thousand and nine.
The announcements and emails were sent,
According to the grand design.
I am at the Observatory,
Ready for the crowds to arrive,
Without a moon, with an open sky,
This year the meteors should thrive.
Sunset is here, but the clouds won=92t part.
And to top it all off, heavy fog.
What if nobody decides to come?
That will not look good in the log.
With fingers crossed and my hopes not lost,
I anxiously sit without fear.
For although it looks quite foreboding,
The Canadians said it would clear!
Yet here I sit, lest someone should come,
Without even one star to see.
For hours and hours, with roof closed;
The lonely astronomer me.
Even the other astronomers,
Who stayed warm, at home, without blame,
On the night we threw a star party,
And the night that nobody came!
by Aaron Clevenson
Wednesday, December 16, 2009
Predictable sprites location - changing lens to have a closer look
note the group on the left and the single 'fork' like on the right
Tuesday, December 15, 2009
Monday, December 14, 2009
Clouded out UT Dec 13 2009
Sunday, December 13, 2009
(UT) 12-Dec-2009 Geminids
Image above showing the 17/25 Gems from UT 14-22 Dec 12 2009
Video posted to youtube
Video posted to youtube
Video 3.8mm f0.8 auto IRIS, wat902H
(UT) |Local time| n |Gem(n) ..
-----------------------------
15 23 3 Gem(2) Hyd(1)
16 00 6 Gem(6)
17 01 6 Gem(4) Urs(1)Spo(1)
18 02 6 Gem(4) nTau(1)Spo(1)
19 03 4 Gem(4)
20 04 4 Gem(3) Urs(1)
21 05 1 Gem(2)
(UT) |Local time| n |Gem(n) ..
-----------------------------
15 23 3 Gem(2) Hyd(1)
16 00 6 Gem(6)
17 01 6 Gem(4) Urs(1)Spo(1)
18 02 6 Gem(4) nTau(1)Spo(1)
19 03 4 Gem(4)
20 04 4 Gem(3) Urs(1)
21 05 1 Gem(2)
Saturday, December 12, 2009
Saturday, December 05, 2009
Geminids Dec 14 2009 Watch Window for SGP
Radiant around mid night (~ 40 degree), Castor Pollux on top left chart.
Credit IMO 2008 Gems actual data ZHR chart
Credit IMO 2008 Gems actual data ZHR chart
Using above chart from IMO last year result as illustration
i) Notice the sharp peak occurred during daylight Singapore time ( 5h 10m UT => 13h 10m Dec 15)
ii) The asymmetric peak - broad activity prior to peak and steep decrease of activity post peak
So lets bracketing the peak -
-watch Dec 12 Sat 9pm onwards till Dec 13 Sunday am
- watch Dec 13 Sun 9pm onwards till Dec 14 Monday 2009.
*Radiant: [ midnight ~ 40 degree] , [3 AM ~ 60 degree]
*The higher the radiant the more Geminids you are going to get.
i) Notice the sharp peak occurred during daylight Singapore time ( 5h 10m UT => 13h 10m Dec 15)
ii) The asymmetric peak - broad activity prior to peak and steep decrease of activity post peak
So lets bracketing the peak -
-watch Dec 12 Sat 9pm onwards till Dec 13 Sunday am
- watch Dec 13 Sun 9pm onwards till Dec 14 Monday 2009.
*Radiant: [ midnight ~ 40 degree] , [3 AM ~ 60 degree]
*The higher the radiant the more Geminids you are going to get.
Wednesday, December 02, 2009
Sunday, November 29, 2009
Saturday, November 28, 2009
November Orionid (NoO) Nov 28 '2009
Not many meteors caught but here is one for the record - November Orionid - this meteor stream was discovered by Sirko malau from the video meteor database. Recognize the constellation of Orion on the top right?
P/S The same region where days earlier a Nova(?) was discovered there (Eridanus) leading to a scramble to ask photographers to reexamine their Leonid images in the hope of finding out the brightest magnitude ( mag 1-2?!!!) prior to discovered date.
ZHR is not the same as HR
When the predicted rate is announced as 500 ( or later scaled down to 200), the public including the media take it as Hourly Rate 500 or 200 perhaps ignoring the 'Zenith' term of Zenith Hour Rate.
A simple worksheet above illustrate the poor LM sky to Predicted ZHR vs Hourly Rate ( HR) . Unless the LM is 6.6 which means 2^(6.5-6.5)=2^0=1 and radiant is directly overhead Sine(90)=1 you will never get the hour rate = ZHR. With our less than ideal LM - the worksheet says ~ 14 Leonids /HR can be seen during the peak. Recompute the above with a good dark site where LM is 6.3. Now you can see the HR is 147 (200Zhr pred), and (500Zhr pred).
So the message is GO for a DARK SITE with good sky to appreciate the high hourly rate. Please also take note that while the shower members dominate during peak not all meteors seen were from Leonids - there are other active meteor streams and background sporadic too.
For coming Geminids ( high radiant around midnite) - if you keep the radiant within edges of your field of view you can check by extrapolation backward path of the meteor.. if it falls within the radiant area then high chance it is a Geminid (Gem) .....
Friday, November 27, 2009
Sprites ( high altitude lightning discharges) Nov 27 am 2009
A group of sprites clustered at the TV antennas of my opposite block. Estimate up to 10 degree in length.
Resource from the youtube- University of Alaska high speed color video imaging
Wednesday, November 25, 2009
Friday, November 20, 2009
Nov 20 2009 - sharply reduced Leonids
Thursday, November 19, 2009
Nov 19 Leonids 2009 - 2nd "bump" in the prediction
Leonids still active and detected in 6am slot .... this bright one 6:21am
UT format of the x7 Leonids
21:48:04
21:41:30
21:53:60
22:18:51
22:20:41
22:21:26* ( image above)
22:2607
( New**- video of these Leonids posted at youtube)
UT format of the x7 Leonids
21:48:04
21:41:30
21:53:60
22:18:51
22:20:41
22:21:26* ( image above)
22:2607
( New**- video of these Leonids posted at youtube)
Wednesday, November 18, 2009
Leonids Nov 18 2009 am
4 am - 1 hr tally count.. lost 50% of sky coverage due to cloud..
The bright dotted on top - Sirius and below Canopus
The bright dotted on top - Sirius and below Canopus
02:56 - cloudy but gap let the meteor through ...but blocked
For those who had struggled to view from midnight till late 3:00am
the sky was really bad. Most of the dimmer meteor's tail would disappeared leaving a small portion of the luminous head.. a blip that could be easily missed.
For those who had struggled to view from midnight till late 3:00am
the sky was really bad. Most of the dimmer meteor's tail would disappeared leaving a small portion of the luminous head.. a blip that could be easily missed.
6:24 am and was getting brighter,
still a fast moving tadpole shaped Leonid on the
upper right image with distinctive terminal burst!
still a fast moving tadpole shaped Leonid on the
upper right image with distinctive terminal burst!
Nov 18 '09 5:00 - 6:00 am ( UT Nov17-21:00 to 22:00 hr)
Predicted Peak ~ 5:40am - note no fireball observed in the 89 degree FOV.
Predicted Peak ~ 5:40am - note no fireball observed in the 89 degree FOV.
Due to the weather condition - layers of thin clouds, it was difficult to see them visually as the dimmer tailed might be hidden in clouds so a tiny portion plus nucleus head left.
[ Bright Star streaks in above stacking: Top right - 'Belt' stars , Rigel (Orion), middle Sirius (Canis Major), mid lower Canopus ]
[ Bright Star streaks in above stacking: Top right - 'Belt' stars , Rigel (Orion), middle Sirius (Canis Major), mid lower Canopus ]
UT
Nov 17__total_ leo_ psu_dad_hyd_noO_spo
18:00-19:00 __1__1_0_0_0_0_0
19:00-20:00 __5__3_0_0_0_ 0_2
20:00-21:00 __9__6_0_0_1_ 0_2
21:00-22:00 _24_14_3_2_ 0_1_4
22:00-22:30 __3__2_0_0_0_ 0_1
Total : total(42), leo(26),psu(3),dad(2),hyd(1),noO(1),spo(9)
Nov 17__total_ leo_ psu_dad_hyd_noO_spo
18:00-19:00 __1__1_0_0_0_0_0
19:00-20:00 __5__3_0_0_0_ 0_2
20:00-21:00 __9__6_0_0_1_ 0_2
21:00-22:00 _24_14_3_2_ 0_1_4
22:00-22:30 __3__2_0_0_0_ 0_1
Total : total(42), leo(26),psu(3),dad(2),hyd(1),noO(1),spo(9)
Thursday, November 12, 2009
OutLook for Leonids 2009 - 1/5 storm level ( scale down from 1/2)
Mikhail Maslov's Prediction chart above grid at 3 hours interval
Watch November 18 Wednesday 2 am till dawn. Time shown is in UT. Add +8 and minus 24 to get into our local time.
Wednesday, November 11, 2009
SM - this is for you
Wednesday, November 04, 2009
Friday, October 30, 2009
Wednesday, October 14, 2009
Orionids in Singapore Oct ( 19/20, 21/22* 13/14, 15, 16,17/18 18/19 )
Oct 21/22 (0 hrs - 06:0am local time ) - x20 ORI, x7 SPO, x1 oct, x1 ocu
Sky was cloudy most of the time. The highlite of the night was a visual detection of moderate speed electric blue tear drop shaped meteor around 10:58 magnitude -4 or brighter bearing AZ=200 elevation ~ 20-30. I was standing by my window looking out and saw this nice meteor coming down at 60 degree. Video system was on but no detection - blocked by the building.
UT* format
2009 Oct 21
16hr: x1
17 hr: x3
18 hr:x2
19 hr:x0
20 hr:x5
21 hr:x4
22 hr:x5
Youtube of our cloudy sky meteors
Sky was cloudy most of the time. The highlite of the night was a visual detection of moderate speed electric blue tear drop shaped meteor around 10:58 magnitude -4 or brighter bearing AZ=200 elevation ~ 20-30. I was standing by my window looking out and saw this nice meteor coming down at 60 degree. Video system was on but no detection - blocked by the building.
UT* format
2009 Oct 21
16hr: x1
17 hr: x3
18 hr:x2
19 hr:x0
20 hr:x5
21 hr:x4
22 hr:x5
Youtube of our cloudy sky meteors
Oct 19/20 - Orionids finally return in sizable number
Radiant plot of individual Ori ( above), red portion actual path
and the composite images ( minus those with heavy cloud background) below.
Radiant plot of individual Ori ( above), red portion actual path
and the composite images ( minus those with heavy cloud background) below.
UT* (ORI) Oct 19 2009
16:57
17:11,17:14
18:11, 18:32,18:24,18:54,18:56
19:06,19:25,19:52
20:03,20:05,20:15,20:31
21:19
22:07,22:10
16:57
17:11,17:14
18:11, 18:32,18:24,18:54,18:56
19:06,19:25,19:52
20:03,20:05,20:15,20:31
21:19
22:07,22:10
( total : x19 ORI, X7 SPO, x1 OcU?)
F0.8 3.8mm
Plotting only the radiant verified x 6 Orionids Oct 19 am.
( total : x6 Orionids, x5 others)
02:15:46
03:03:22
04:51:38
04:52:37
05:17:15
06:04:04
Plotting only the radiant verified x 6 Orionids Oct 19 am.
( total : x6 Orionids, x5 others)
Finally orionids showing up in small numbers.
Sirius and Canopus dotted in
this composite stacked image .
Time stamps (hr:min:sec) of the six AM orionids
to give you a feel of when and how bright/dim they were
Oct 19 2009Sirius and Canopus dotted in
this composite stacked image .
Time stamps (hr:min:sec) of the six AM orionids
to give you a feel of when and how bright/dim they were
02:15:46
03:03:22
04:51:38
04:52:37
05:17:15
06:04:04
Oct 17 - evening a nice sporadic meteor with multiple flares flashed past Jupiter,
while another slow moving one 'dashed' near
the lower bottom frame.
while another slow moving one 'dashed' near
the lower bottom frame.
Oct 13/14 , Sirius at top centre frame
Lone Orionid (top) out of the total 1+4 meteors detected.
Ori 1/5=20% , SPO 3/5=60% , Taurid 1/5= 20%
Lone Orionid (top) out of the total 1+4 meteors detected.
Ori 1/5=20% , SPO 3/5=60% , Taurid 1/5= 20%
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