Nov 24/25/26/27 Meteors

As the rain falls (a little) on Tucson, I’ll let Bob summarize the meteor totals over the past few nights.

Bob’ notes for the night of Nov 26/27 : “Rates were down significantly tonight with big drops in the NTA’s and sporadics. The waxing gibbous moon is starting to take it’s toll on sky conditions and reducing meteor rates.”

… for the night of Nov 25/26 : “It was another totally clear night. Totals were similar to yesterday but without the wide swings in activity. The Northern Taurids were especially strong tonight producing 21% of the total activity.”

… for the night of Nov 24/25 : “Another totally clear night. Totals were similar to yesterday but the hourly rates were quite variable with wide swings in activity. The evening hours were unusually quiet. Perhaps the first quarter moon is beginning to show its effects. This was the last night for Alpha Monocerotid activity. While we say goodbye to this shower tomorrow we welcome the more active Sigma Hydrids, which peak on December 6th.”

Obs  Date(UT)      Time    TOT SPO ANT NTA STA LEO AMO NOO AND HYD
TUS  2009-11-27   11h58m    29  18  1   -   -   2   -   6   0   0
SDG  2009-11-27   11h46m    53  38  -   7   -   1   -   4   1   2
TUS  2009-11-26   12h00m    47  35  3   -   -   2   -   10  0   0
SDG  2009-11-26   11h52m    70  46  -   15  -   3   -   3   1   2
TUS  2009-11-25   11h58m    45  31  -   1   3   3   3   4   0   -
SDG  2009-11-25   11h49m    64  41  -   9   -   4   3   5   2   -

TUS – Camera in Tucson operated by Carl Hergenrother
SDG – Camera in San Diego operated by Bob Lunsford
TotTime – Total amount of time each camera looked for meteors
TOT – Total number of meteors detected
SPO – Sporadics (meteors not affiliated with any particular meteor shower)
NTA/STA – Northern and Southern Taurids (includes Antihelions)
LEO – Leonids
AMO – Alpha Monocerotids
NOO – November Orionids
AND – Andromedids

Nov 21/22/23/24 Meteors

Nightly rates remain high which is not unusual for this time of the year. The brightening Moon should start to suppress the number of meteors which can be seen.

Bob’ notes for the night of Nov 23/24 : “It was a brilliantly clear night and meteor rates were near what is expected this time of year.”

… for the night of Nov 22/23 : “Skies cleared up nicely compared to last night. Meteor totals were a bit less than what was expected with the nice, transparent skies.”

… for the night of Nov 21/22 : “Clouds largely spoiled tonight’s observations. The start was delayed by clouds. The sky cleared near 9pm PST and it remained mostly clear for the next 4 hours. It clouded up again near 1am PST and remained cloudy the remainder of the night.”

Obs  Date(UT)      Time    TOT SPO NTA STA LEO AMO NOO AND
TUS  2009-11-24   11h35m    47  25  7   1   7   3   2   2
SDG  2009-11-24   11h49m    66  49  7   -   4   1   3   2
TUS  2009-11-23   11h20m    54  36  1   4   6   5   2   0
SDG  2009-11-23   11h46m    51  36  7   -   2   2   3   1
TUS  2009-11-22   11h34m    47  29  3   1   4   5   4   1
SDG  2009-11-22   04h00m    11  5   3   -   0   1   2   0

TUS – Camera in Tucson operated by Carl Hergenrother
SDG – Camera in San Diego operated by Bob Lunsford
TotTime – Total amount of time each camera looked for meteors
TOT – Total number of meteors detected
SPO – Sporadics (meteors not affiliated with any particular meteor shower)
NTA/STA – Northern and Southern Taurids (includes Antihelions)
LEO – Leonids
AMO – Alpha Monocerotids
NOO – November Orionids
AND – Andromedids

Nov 20/21 Meteors

Clouds have started to creep back into the American Southwest. Though they were little more than a temporary nuisance in Tucson, they cut Bob’s night in half at his  sight in San Diego. The Leonids are still hanging on at a much reduced level from earlier in the week. The Tucson cameras also appeared to pick up some healthy activity from the Alpha Monocerotids which were predicted to be near their peak last night.

Bob’ notes for the night of Nov 20/21 : “It was clear up to 0700 UT (11pm PST). After that it was partly cloudy for most of the remainder of the night. After 1200 UT (4am PST) it was almost totally overcast. Meteor totals were only half of what was recorded the previous night. The weather forecast is for more favorable skies tonight through the Thanksgiving holiday.”

Obs  Date(UT)      Time    TOT SPO NTA STA LEO AMO NOO AND OER
TUS  2009-11-21   07h59m    48  24  1   1   8   7   4   0   2
SDG  2009-11-21   10h55m    31  22  5   -   1   0   3   0   -

TUS – Camera in Tucson operated by Carl Hergenrother
SDG – Camera in San Diego operated by Bob Lunsford
TotTime – Total amount of time each camera looked for meteors
TOT – Total number of meteors detected
SPO – Sporadics (meteors not affiliated with any particular meteor shower)
NTA/STA – Northern and Southern Taurids (includes Antihelions)
LEO – Leonids
AMO – Alpha Monocerotids
NOO – November Orionids
AND – Andromedids
OER – Omicron Eridanids

Nov 19/20 Meteors

The Leonids are becoming much fewer in number. Still the relatively high number of Sporadic meteors is keeping the nightly totals elevated.

My 2 cameras produced an interesting result last night. The zenith (straight-up) camera found a half-dozen or more meteors that appeared to radiate from a broad area on the Ursa Major/Lynx border. But, the north camera, which also happened to directly image the supposed “radiant” saw nothing from that area. The lack of agreement between the two cameras suggests that either a) this was just a fluke alignment, or b) bad astrometry and these were actually Leonids, or c) there was an unknown shower active last night. Personally I believe explanation ‘a’.

Bob’ notes for the night of Nov 19/20 : “It was clear and transparent all night long. Rates were back up to what was expected. The Northern Taurids were the most active shower surpassing the Leonids.”

Obs  Date(UT)  Time    TOT SPO NTA STA LEO AMO NOO AND OER
TUS  Nov-20   11h52m    52  28  4   3   11  2   2   1   1
SDG  Nov-20   11h55m    66  44  9   -   6   2   4   0   1

TUS – Camera in Tucson operated by Carl Hergenrother
SDG – Camera in San Diego operated by Bob Lunsford
TotTime – Total amount of time each camera looked for meteors
TOT – Total number of meteors detected
SPO – Sporadics (meteors not affiliated with any particular meteor shower)
NTA/STA – Northern and Southern Taurids (includes Antihelions)
LEO – Leonids
AMO – Alpha Monocerotids
NOO – November Orionids
AND – Andromedids
OER – Omicron Eridanids

Update on Nova V496 Scuti

Nova V496 Scuti is still near maximum brightness at magnitude ~7.4. For the back story on this object check out my post from Nov 15: “Nova Scuti 2009 = V496 Scuti“.

The plot below was created by the American Association of Variable Star Observers (AAVSO) from their archives. It includes 97 observations made by 33 observers from 13 countries. The blue crosses represent my own observations which were made visually with 30×125 binoculars. You can also check out Salvador Aguirre’s blog (in Spanish) for his observations of V496 Scuti.

The nova has been rather steady in its brightness for the past 5 days or so. Based on the data below, it’s possible it is still slowly brightening. Regardless, at some point in the next week or so, the nova should start to rapidly fade. I say should because some nova have been known to stay bright for weeks to months and even experience multiple outbursts.

AAVSO archival data of nova V496 Scuti. Credit: AAVSO (www.aavso.org)

Meteor Activity Outlook for November 21-27, 2009

The Meteor Activity Outlook is a weekly summary of expected meteor activity written by Robert Lunsford, Operations Manager of the American Meteor Society and contributor to this blog. The original unedited version of this week’s Meteor Activity Outlook can be found at the American Meteor Society’s site.

As seen from the northern hemisphere, meteor rates continue to be strong in November. While no major showers are active this month, the two Taurid radiants plus the Leonids keep the skies active. The addition of strong sporadic rates make November one of the better months to view meteor activity from north of the equator. Skies are fairly quiet as seen from the southern hemisphere this month. Activity from the three showers mentioned above may be seen from south of the equator, but the sporadic rates are much lower than those seen in the northern hemisphere.

During this period the moon reaches its first quarter phase on Tuesday November 24th. On that date the moon lies ninety degrees east of the sun and will set near midnight local standard time (LST). This weekend the waxing crescent moon will set long before the more active morning hours arrive, allowing dark skies for those who venture out during the morning hours. As the week progresses the moon sets later each night narrowing the window of opportunity to view under dark conditions. The estimated total hourly rates for evening observers this week is near four as seen from the northern hemisphere and three from the southern hemisphere. For morning observers the estimated total hourly rates should be near twenty from the northern hemisphere and ten as seen from the southern hemisphere. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Rates are reduced during the evening hours due to moonlight.

The radiant positions and rates listed below are exact for Saturday night/Sunday morning November 21/22. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following showers are expected to be active this week.

Andromedids (AND)

Sirko Molau’s studies of video radiants has revealed that activity from the famous Andromedid shower, noted for intense storms during the 19th century, may still be seen throughout November. This position lies in eastern Andromeda, two degrees south of the fourth magnitude star Nu Andromedae. The nearest bright star is second magnitude Almach (Gamma Andromedae), which lies four degrees to the northeast. Visual activity is expected to be low, but detectable. The Andromedid radiant is best placed near 2200 (10pm) local standard time (LST) when it lies on the meridian. At 19km/sec., the average Andromedid will appear as a very slow moving meteor. Sirko mentions that these meteors are “conspicuously slow and of almost constant activity” during this period.

Northern Taurids (NTA)

The Northern Taurids (NTA) are active from a large radiant centered at 04:29 (067) +24, which lies in northern Taurus, eight degrees north of the orange first magnitude star Aldebaran (Alpha Tauri). The radiant is best placed near 0100 LST, when it lies highest above the horizon, but activity may be seen all night long. Meteors from the Northern Taurids strike the atmosphere at 29km/sec., which would produce meteors of slow velocity. Expected rates would be ~3 per hour as seen from the northern hemisphere and ~2 per hour as seen south of the equator.

November Orionids (NOO)

The November Orionids (NOO) were recently discovered by analyzing video data. This shower is active from November 18 through December 9. Maximum activity occurs on November 30. The radiant is currently (11/18) located at 05:44 (086) +15. This position lies on the Orion/Taurus border, six degrees north of the third magnitude star Lambda Orionis. These meteors are also best seen near 0300 LST when the radiant lies on the meridian and highest above the horizon. At 44 km/sec. the November Orionids produce mostly medium velocity meteors.

Alpha Monocerotids (AMO)

The Alpha Monocerotids (AMO) are active from November 15-25, with maximum occurring on the 21st. This shower has produced outbursts in the past but none are expected for many years to come. Rates are expected to be < 1 shower member per hour, even on the night of maximum activity. The radiant is currently located at 07:52 (118) +01. This position lies in southeastern Canis Minor, five degrees southeast of the zero magnitude star Procyon (Alpha Canis Minoris). These meteors are also best seen near 0500 LST when the radiant lies highest above the horizon in a dark sky. At 65 km/sec. the Alpha Monocerotids produce mostly swift meteors.

Leonids (LEO)

The Leonids (LEO) reached maximum activity on the morning of November 17th with ZHR’s exceeding 100 as seen over Asia. Current rates would be near one per hour no matter your location. The radiant is currently located at 10:27 (157) +20. This position lies in western Leo, just one degree northeast of the famous second magnitude double star Algeiba (Gamma Leonis). At 70km/sec., the average Leonid is swift with a high percentage of trains. The radiant does not rise until the late evening hours so it is advised to wait until after midnight before beginning serious observations. The radiant is most favorably located during the last dark hour before the onset of morning twilight when it lies highest in a dark sky.

As seen from the mid-northern hemisphere (45N) one would expect to see ~16 Sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be ~3 per hour. As seen from the mid-southern hemisphere (45S), morning rates would be ~6 per hour as seen from rural observing sites and ~2 per hour during the evening hours. Locations between these two extremes would see activity between the listed figures.

The table below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning but may be used all week long.

Shower Name                RA     DEC   Vel     Rates
                                        km/s   NH    SH
AND Andromedids          01h 38m  +39    19    <1    <1
NTA Northern Taurids     04h 29m  +24    29     3     2
AMO Alpha Monocerotids   07h 52m  +01    65    <1    <1
LEO Leonids              10h 27m  +20    70     1     1

RA - Right Ascension
DEC - Declination
Vel - Velocity relative to Earth (in km per sec)
Rates - Rate of visible meteors per hour from a
        dark site
NH - Northern Hemisphere
SH - Southern Hemisphere

Nov 18/19 Meteors

Leonid activity is rapidly decreasing in intensity with rates less than half of what they were just a night ago. Still the nights are producing lots of meteors. Last night saw a large number of “long” meteors that traveled over 20 degrees of sky. The best example can be seen in the video below. This sporadic meteor was seen at 9:22 pm MST (4:22 UT). It actually starts in the FOV of my zenith camera before moving far enough north to enter the FOV of my northern camera (the video below is from the north camera). If you look closely at the beginning of the video you will notice material falling off the meteor. Unfortunately my system dropped a few frames which is why the meteor appears to jump ahead a few times.

Bob’ notes for the night of Nov 18/19 : “Clouds plagued observations most of the night so meteor numbers are far below what they should be.”

Obs  Date(UT)  Time    TOT SPO NTA STA LEO AMO NOO AND OER
TUS  Nov-19   11h51m    69  35  4   4   17  2   5   1   1
SDG  Nov-19   07h42m    37  25  2   2   8   0   2   0   0

TUS – Camera in Tucson operated by Carl Hergenrother
SDG – Camera in San Diego operated by Bob Lunsford
TotTime – Total amount of time each camera looked for meteors
TOT – Total number of meteors detected
SPO – Sporadics (meteors not affiliated with any particular meteor shower)
NTA/STA – Northern and Southern Taurids (includes Antihelions)
LEO – Leonids
AMO – Alpha Monocerotids
NOO – November Orionids
AND – Andromedids
OER – Omicron Eridanids

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