(meteorobs) NAMN Notes: January 2009

[meteors at comcast.net]

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NAMN Notes: January 2009
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NAMN Notes is a monthly newsletter produced by the North American Meteor
Network and is available both via email and on the NAMN website at:

http://www.namnmeteors.org

* Last Major Shower of Winter; Look Quick by the Dawn’s Early Dark.
* Plenty of Minor Showers for the Brave (and Well Prepared)
* Wrapping up 2008

1. QUA - Quadrantid (Bootid) Shower...
2. Swift Meteors from Coma Berenices...
3. ANT - Antihelion Activity...
4. Targets for the Experienced Observer...
5. Please submit 2008 observations...
6. Index to 2008 NAMN Notes...


1. QUA - Quadrantid (Bootid) Shower...

The last major shower of the winter season occurs just as the earth
reaches perihelion on January 3rd. The Quadrantid shower has a ZHR as
high as that of the Perseids and Geminids, but observing conditions are
rarely as favorable. The true peak only lasts a few hours. In 2008, the
eastern US was the favored location, but this year it will be best seen
somewhere between the US west coast and Japan. That is an area with few
points of terra firma!

The IMO gives the annual peak time as Solar Longitude 283.16, or 12:50
UT on January 3rd. Last year was pretty well covered by eastern and
central US NAMN members (10 total), indicating a peak from Solar
Longitude 283.244 to 283.329, about 2 hours later. In fact this is
probably one of the top few Quadrantid peaks with substantial coverage.
At the NJAA, there were two experienced observers and we showed a peak
rate toward the end of the period mentioned above. The IMO peak ZHR was
shown at SL 283.285 (ZHR 82 +/-8) or 0936 UT, while NJAA observations by
Wayne Hally and Pierre Martin showed a peak ZHR of 91 +/-10 at SL
283.329 (1039 UT). Pierre drove from Ottawa to New Jersey for the clear
skies and the warmth; after all it was a balmy 12 degrees F! To view the
IMO visual data (preliminary only) see:

http://www.imo.net/live/quadrantids2008/

Based on the “normal” peak and last year’s timing, the east coast will
see only the rising rates before the peak. The further west you are in
the US and Canada and westward across the International Date Line, the
better your opportunity to capture the peak will be. It would be
expected between 1300 and 1700 UT on January 3rd. That is 8 AM to Noon
EST, and 5 AM to 9 AM PST. You can therefore see why the further west
the better your location will be. The sun rises between 7 and 7:30 AM in
North America and the moon sets around midnight, so there are a few dark
hours to collect some good counts. I should point out that data on this
shower is rather sparse, so a peak a few hours either side of these
times is certainly possible.

IMO Video data has indicated a longer period of activity than in the
official working list. Before January 1st and after the 5th, extreme
care should be used in assigning meteors to this shower even though I
list the positions below. These are moderately fast meteors with a
velocity of 41 km/sec.

It was suspected that the parent object of this shower was comet
96P/Machholz 1, but recent investigations by Jenniskens, Vaubaillon,
Marsden and others has pointed the fickle finger of origin on another
object, asteroid 2003 EH1. Since the particular orbit of the asteroid,
the comet, and the meteoroids quickly evolve (nutate) it is quite
possible all of them are related. The current inclination of the meteor
stream, for example, of 72 degrees was 13 degrees only 1500 years ago.
We are fortunate to be in the path of this stream at this time.

The radiant is named for a constellation that no longer exists; on
today’s map of the sky it is in northern Bootes between magnitude +3.5
Nekkar (the top of the “kite” of Bootes) and Draco’s sinuous body.

If the weather cooperates, bundle up and enjoy the show!

QUA (Quadrantids) - velocity 41 km/sec (medium)
UT Date, RA degrees (Hr:mm), Declination
Jan 01   229 (15:14), +50
Jan 03   230 (15:19), +49 (Peak)
Jan 05   231 (15:24), +49 (End of working list activity)
Jan 09   233 (15:34), +48 (Last morning with some moon free time)


2. Swift Meteors from Coma Berenices...

As discussed last month, we have multiple radiants to look at for the
Comae Berenicid shower. The COM radiant listed below is the historical
location, while the CBE radiant is that verified by video observations
over the last decade. Both can (and should) be reported to the NAMN and
IMO, assigning each related meteor to one shower or the other. The
radiants are over 15 degrees apart, so with judicious choice of your
field of view, it should be pretty easy to do so. Both peaked in late
December and continue until at least January 23rd, with the video data
showing activity extending until early February. These are very fast
meteors, with a velocity of 65 km/sec, so should really stand out. The
radiants are both above and “behind” Leo in the morning sky. The IAU’s
JCO (January Comae Berenicids) shower, while only 4 days long, is
coincident with the CBE position from the 19th to the 23rd, so they
should be reported as CBE meteors.

COM and CBE - Comae Berenicids, velocity 64-65 km/sec

UT Date COM RA deg, (Hr:mm), Dec; CBE RA deg, (HR:mm), Dec
Jan 01  COM 187 (12:27), +20; CBE 172 (11:27), +26
Jan 06  COM 191 (12:43), +18; CBE 176 (11:45), +24
Jan 11  COM 195 (12:59), +17; CBE 182 (12:07), +21 (Full Moon)
Jan 17  COM 200 (13:16), +14; CBE 187 (12:26), +18
Jan 23  COM 204 (13:38), +12; CBE 191 (12:46), +16 (Official end)
Jan 30                        CBE 199 (13:15), +14


3. ANT - Antihelion Activity...

The Antihelion radiant continues its eastward march during the month.
This shower consists of multiple, low activity showers over a rather
wide area about 20 degrees east and west along the ecliptic, and 5
degrees above and below. Video data shows “peaks” of activity on the 5th
and 14th, before and after the Full Moon. The radiant moves from eastern
Gemini, through Cancer, and into western Leo during the month.

ANT - Antihelion Radiant, velocity ~ 30 km/sec
UT Date, RA deg (Hr:mm), Dec
Jan 01   113 (7:32), +21
Jan 06   118 (7:52), +20
Jan 11   123 (8:12), +19
Jan 16   128 (8:32), +17
Jan 21   133 (8:53), +16
Jan 26   139 (9:16), +15
Jan 31   144 (9:36), +13


4. Targets for the Experienced Observer...

For those who brave the elements during midwinter, we need to supply
some other targets to keep the mind sharp (and warm). The following
showers are derived from video data, as well as photographic and radar
surveys, and includes one on the IMO working list that is only
accessible for our most southern observers.

We’ll start with a working list shower, the alpha-Centaurids (ACE). This
is a far southern shower; in fact the radiant just peeks over the
horizon before dawn for southern Florida, southern Mexico and Hawaii.
There is a paucity of good data, and realistically little scientific use
can be made from any sightings in North America, but it’s an interesting
target for those with alpha Centauri in view. The radiant is about 20
degrees due south of the jewel like Omega Centauri cluster. Activity
begins on January 28th, so I will just give the position for the 31st.
It is located at RA 201 (13:25), Dec -57, and the meteors are fast at 56
km/sec.

Next is a shower detected in video data that has also recently been
added to the IAU working list based on radar data. It is the
alpha-Hydrids (AHY). Low visual meteor rates have been seen from this
shower; NAMN observers reported 5 last January. In Sirko Molau’s 2006
list it was shower #89, the refined 2008 list labels it shower #148, it
is IAU shower #331. These are medium fast meteors with a velocity
between 40 and 44 km/sec, and the radiant is between Monoceros and the
2nd magnitude star alpha Hydrae, the brightest star below Hydra’s head.

AHY - alpha Hydrids, velocity ~42 km/sec
UT Date,  RA deg (Hr:mm), Dec
Jan 01    126 (8:22), -09
Jan 06    129 (8:34), -09 (Peak)
Jan 09    130 (8:42), -09 (Last morning with moon free time)

Another shower of interest is the January Leonids. The radiant is within
the “Sickle” of Leo at its peak. It was Sirko Molau’s shower 86 in 2006,
and matches well with IAU shower #319. These are swift meteors, with a
velocity of ~ 54 km/sec. It shows some visual activity from about
December 31 to January 7th, with a peak on the 3rd or 4th.

JLE - January Leonids, velocity 54 km/sec.
UT Date,  RA deg (Hr:mm), Dec
Jan 01    148 (09:53), +24
Jan 07    152 (10:07), +22

Next up is Sirko Molau’s 2006 shower #88, the iota-Cancrids (ICA). These
are medium fast meteors with a velocity of 39 km/sec. They are also
active and peak at the same times as the JLEs above

ICA - iota-Cancrids, velocity 39 km/sec.
UT Date,  RA deg (Hr:mm), Dec
Jan 01   131 (8:43), +32
Jan 07   131 (8:43), +22

Finally I will mention another shower; this is the southern apex radiant
(SPX) which exists all year long in the direction the earth is moving. A
few times during the year there is some enhancement in rates. This one
was seen in 2006 video data from the 1st to 6th. These are fast meteors
(since we hit them head on) at about 62 km/sec. This radiant is in the
constellation Crater, just to the west (right) of the squashed square of
Corvus.

SPX - Southern Apex
UT Date,  RA deg (Hr:mm), Dec
Jan 01   178 (11:52), -24
Jan 06   171 (11:24), -18


5. Please submit 2008 observations...

Now that 2008 has ended, if you have any observing sessions from the
year lying around that you haven’t submitted, please try and find some
time to finish them up before the end of January. During the slow months
from now until the Lyrids, I’d like to compile the 2008 annual summary
of NAMN observations. Of course, you can send in your data any time and
it will be included in our database, but I’d like the 2008 (and
2004-2008) summary that will be included in the NAMN Notes, and posted
on the website, to be as complete as possible. Your cooperation is
greatly appreciated, as are all the efforts that we all make to document
the quickly moving objects of the sky!


6. Index to 2008 NAMN Notes...

Here is the index for subjects in the 2008 NAMN Notes. It has been my
pleasure (and challenge) to serve the meteor community during this year.
2009 is the International Year of Astronomy (the 400th Anniversary of
Galileo turning his telescope to the sky) and the moon will be far
friendlier this year. Hopefully we can together spend more time and
record more meteors than ever before.

January 2008
Quadrantids: Best Shower of the Year So Far...
Other January Activity...
For the Advanced Observer...
2008 Outlook...

February 2008
No February 2008 issue published...

March 2008
NAMN Notes Missing for February...
March’s Sparse Showers...
Quick Review of 2007...
Quick Review 2008 Quadrantids...
The Meteor Month...

April 2008
Challenging Lyrids for 2008...
A Southern Shower peeking above the Horizon (PPU)...
The eta-Aquarids (ETA) Compete with Dawn and the Moon...
Ecliptic (ANT) meteors for April...
Targets for Plotting...
The Meteor Moonth...
Index to 2006 Articles...

May 2008
(ETA) The eta-Aquarids Greet the Dawn...
(ELY) This Newer Shower is Worth Looking for...
(ANT) Antihelion Showers in May...
The Nights Get Shorter...
Lyrids Squashed by the Moon...

June 2008
June: The Last Slow Month...
June Bootids (JBO) the Shower of the Month...
(ANT) Antihelion Activity...
Other Showers of Interest...
Magnitude References...

July 2008
July’s Southern Showers...
The Perseids Perk Up...
A Multitude of Minor Showers...
Magnitude References...

August 2008
The Perseids - The Public’s Shower...
July’s Southern Showers Wind Down...
KCG, the “Other” August Shower...
Other Showers of Interest...
New Showers from Video Data...
Magnitude References...

September 2008
(AUR) alpha-Aurigids, No Outburst Expected This Year...
(SPE-DAU) Two Minor Showers on a Common Path...
(NTA-STA) The Taurids Spice Up the Antihelion Radiant...
(ERI-EER) Potential Activity from Eridanus...
Active Period for the Southern Apex Sources...
Showers Detected in Video Records...
Early Perseid Results...

October 2008
ORI - Halley’s Comet Dust Returns Again...
Will the Draconids (GIA) Roar?...
STA & NTA - New Taurid Data...
Minor Showers EGE and LMI...
DAU - Leftover Aurigids...
Sky References...

November 2008
Have the Leonids Returned to Being a Minor Shower?...
Autumn’s Showers Wind Up and Down...
Don’t Blink or You Might Miss an AMO Outburst...
The Andromedids Live...
Winter’s Showers Start Earlier Than Expected...
Sky References...

December 2008
Geminids Too Friendly with the Moon...
Moon Free Ursids...
Dark Skies to Investigate the Comae Berenicids...
Antihelion Radiant Returns...
Minor Showers of December...
2009 Quadrantids...


For radiant positions and more detailed descriptions of showers, see the
IMO 2009 Meteor Shower Calendar at:  http://www.imo.net/calendar/2009

For assistance in understanding how to estimate limiting magnitude (the
faintest stars you can see) the NAMN has a tool available here:

http://www.namnmeteors.org/lm_calc.html

It’s especially helpful for those new to the process.

For those who wish to look for other minor showers not listed here, or
want daily radiant positions for all the showers, drop me an e-mail at
my meteoreye address below, and I’ll send you my current Excel spreadsheet.

Feel free to contact us for questions and comments!!

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NAMN email: namn at namnmeteors.org
NAMN website: http://www.namnmeteors.org

Mark Davis, meteors at comcast.net
Goose Creek, South Carolina, USA
Coordinator, North American Meteor Network

Wayne T Hally, meteoreye at comcast.net
High Bridge NJ
Writer, NAMN Notes

Lew Gramer, dedalus at alum.mit.edu
Homestead, Florida, USA
Coordinator, Public Outreach
Owner/Moderator, 'MeteorObs'

Kevin Kilkenny, namnfireball at earthlink.net
Staten Island, New York, USA
Coordinator, Fireballs and Meteorites

Back issues of NAMN Notes can be found online at the NAMN website and in
the MeteorObs archives at:
http://www.meteorobs.org by selecting 'Browse Archive by Month'

To subscribe to the meteor email list:
Contact Lew Gramer at: dedalus at alum.mit.edu

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Here's to 'Clear Skies' for January...

January 2009 NAMN Notes
Written by Wayne T. Hally & edited by Mark Davis
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