APOD: Geminid Meteor Shower over Dashanbao... (2013 Dec 13)

[Anthony Barreiro]

The apod image of Jupiter in Taurus is almost certainly from 2011.
2012 was my 35th year of following Jupiter; going though nearly exactly 3 orbits back in the feet of Gemini.

My planetarium software, sky safari, agrees with the apod caption. On December 14, 2012, Jupiter was 2 degrees north of Epsilon Tauri, the bull's dimmer eye, as seen in the picture. On December 14, 2011, Jupiter was 7 degrees northeast of Alpha Piscium, the knot tying the two fish together. I think you might have gotten off by a year here or there. 36 years is a long time!

This has been stuck in my mind since yesterday. Planetarium software is very helpful, but what did people do before we had electronic digital computers? Well, we know that Jupiter takes about 12 years to transit through the zodiac, traveling an average of about 30 degrees of ecliptic longitude (or one tropical zodiac sign) per year. By looking up at the sky we see that Jupiter is currently conjunct Wasat, Delta Geminorum, which a star atlas shows is about ecliptic longitude 110 degrees. Therefore one year ago Jupiter would have been about ecliptic longitude 80 degrees, between the horns of Taurus, Beta and Zeta Tauri. This is further east than the location the software shows for Jupiter on December 14, 2012, but much closer than 50 degrees ecliptic longitude, east of the eastern head of Pisces and the stars of Aries, where it would have been two years ago, on December 14, 2011. The planetarium software shows that on December 14, 2011 Jupiter was actually closer to Alresha, Alpha Piscium, about 30 degrees ecliptic longitude.

Now I need to figure out why Jupiter has been traveling about 40 degrees of ecliptic longitude per year for the past two years, rather than 30 degrees per year. Hmm, Kepler's laws of planetary motion? Perhaps Jupiter is close to perihelion and therefore traveling faster than average? Okay, I cheated here and did a quick web search which showed that Jupiter was in fact at perihelion on March 18, 2011.

But the general point is that a naked-eye observation, one basic piece of memorized information, and a simple star atlas gives a good enough double check of Jupiter's location during the past couple of years. This could be useful if all our electronics are fried by an electromagnetic pulse from a nearby supernova.

[Chris Peterson]

Not many 'ordinary' meteors, probably due to the thin haze, but lots of very bright ones (fireballs?), is this pattern usual for the Geminids or was there an outburst ? Anyone have links to analysis of the activity ?

This is the activity I've seen over the last four nights. This is from video observations, so only meteors brighter than mag 2 are recorded (probably mag 1 given the bright moon). So figure visual rates were 3-5 times higher.

The Geminids do tend to produce quite a few fireballs.

[Chris Peterson]

Click to view full size image 1 or image 2

Here's my updated video composite, showing the last four nights. 327 Geminids in all; hover over the image to see just the 171 Geminids recorded last night.

More information and some fireball videos are on my report page.

Here's the complete breakdown of meteors recorded over the last four nights. Again, only the Geminids are shown in the composite images. The Moon and non-Geminid meteors have been removed.

• Andromedid 10
  Puppid-Velid 18
  Monocerotid 31
  chi Orionid 5
  sigma Hydrid 24
  Geminid 327
  46P 16
  Sporadic 45
  Unknown 22
  
  Total meteors: 498

The count of sporadics and unknowns is different from that given in my earlier post because there was a bug that was mixing some Geminids into those categories, giving overly large values. These new numbers should be correct.

[owlice]

I have not been so entertained by a meteor shower since the Leonid outburst of 200? Gosh that seems so long ago now!

And no wonder it does! I'm quite surprised to learn that you were entertained by that Leonid burst at all!

[Beyond]

I have not been so entertained by a meteor shower since the Leonid outburst of 200? Gosh that seems so long ago now!

200 Gee, That was long ago I wasn't around here then. Perhaps you could check with neufer. He once mentioned that he was as old as dirt, so he might remember the outburst of 200.

[Nitpicker]

The apod image of Jupiter in Taurus is almost certainly from 2011.
2012 was my 35th year of following Jupiter; going though nearly exactly 3 orbits back in the feet of Gemini.

My planetarium software, sky safari, agrees with the apod caption. On December 14, 2012, Jupiter was 2 degrees north of Epsilon Tauri, the bull's dimmer eye, as seen in the picture. On December 14, 2011, Jupiter was 7 degrees northeast of Alpha Piscium, the knot tying the two fish together. I think you might have gotten off by a year here or there. 36 years is a long time!

This has been stuck in my mind since yesterday. Planetarium software is very helpful, but what did people do before we had electronic digital computers? Well, we know that Jupiter takes about 12 years to transit through the zodiac, traveling an average of about 30 degrees of ecliptic longitude (or one tropical zodiac sign) per year. By looking up at the sky we see that Jupiter is currently conjunct Wasat, Delta Geminorum, which a star atlas shows is about ecliptic longitude 110 degrees. Therefore one year ago Jupiter would have been about ecliptic longitude 80 degrees, between the horns of Taurus, Beta and Zeta Tauri. This is further east than the location the software shows for Jupiter on December 14, 2012, but much closer than 50 degrees ecliptic longitude, east of the eastern head of Pisces and the stars of Aries, where it would have been two years ago, on December 14, 2011. The planetarium software shows that on December 14, 2011 Jupiter was actually closer to Alresha, Alpha Piscium, about 30 degrees ecliptic longitude.

Now I need to figure out why Jupiter has been traveling about 40 degrees of ecliptic longitude per year for the past two years, rather than 30 degrees per year. Hmm, Kepler's laws of planetary motion? Perhaps Jupiter is close to perihelion and therefore traveling faster than average? Okay, I cheated here and did a quick web search which showed that Jupiter was in fact at perihelion on March 18, 2011.

But the general point is that a naked-eye observation, one basic piece of memorized information, and a simple star atlas gives a good enough double check of Jupiter's location during the past couple of years. This could be useful if all our electronics are fried by an electromagnetic pulse from a nearby supernova.

It is difficult to make conclusions based on observations of Jupiter made every Earth year. The average synodic period of Jupiter (i.e. time between oppositions) is ~399 days. The last two oppositions of Jupiter (late 2011 & 2012) were separated by ~35° in ecliptic longitude. On average, there are 10.86 synodic periods within one Jovian orbital period, meaning that the average movement of Jupiter between oppositions would be more like 33° in ecliptic longitude. So, I'd say that the Earth's own orbit has as much of an effect on the apparent position of Jupiter, as does the eccentricity of Jupiter's orbit.

[Prospero]

200 Gee, outburst of 200.

Ummm, hehee, are you and owlice being deliberatly obtuce, or for comic effect, or ,,, ?
I said 200? as in a wild card, perhaps I shudav typed 200*, it may have been 2000, 2001, 2002 etc&etc, I had a hope that someone would assist my enfeebled brain and say "Oh yes! I remember that, it was , , , " !
Ah well , ,
Anyhow,

Thank you Chris Peterson, (we need a 'like button' !) very interesting graph, looks like there was a bit of a peak in activity +/-4utc when I was casually observing.
Even more so at 10utc, who was in darkness then ?australasia, china, ? any visual reports from there I wonder ?

[geckzilla]

We can't read your mind, Prospero. If you leave things up for grab like that, prepare to become comic relief.

[Beyond]

ha-ha, one more zero would have done it for me. If you had said 2000? I would have taken it as you meant, what year in the first decade of this century.
Oh well, a little fun is good also.

Geckzilla beat me. Yeah, what she said

[Chris Peterson]

Thank you Chris Peterson, (we need a 'like button' !) very interesting graph, looks like there was a bit of a peak in activity +/-4utc when I was casually observing.

That peak is probably an illusion. We had some thin overcast between about 5 and 7, and around 8. Otherwise, the activity probably rose steadily with the rise of the radiant at my location. The apparent structure isn't likely to be real- the Geminid debris stream is fairly broad and uniform.

Even more so at 10utc, who was in darkness then ?australasia, china, ? any visual reports from there I wonder ?

Well, it was dark here! The peak is at 3am local, and coincides with the radiant being nearly at my zenith. I watched the sky a few times during the night from bed, and saw quite a few nice meteors.

[Prospero]

We can't read your mind, Prospero. If you leave things up for grab like that, prepare to become comic relief.

no obs tonight, total cloud and persisting down !

Beyond> "ha-ha, one more zero would have done it for me. If you had said 2000?"
Yep, I see what you mean,
"a little fun"
quite so, couldnt agree more ! this text stuff is a poor medium

[Chris Peterson]

We can't read your mind, Prospero. If you leave things up for grab like that, prepare to become comic relief.

FYI, intense Leonid activity occurred in 1998-2002. 2001 and 2002 were the best years for U.S. observers.

[Prospero]

FYI, intense Leonid activity occurred in 1998-2002. 2001 and 2002 were the best years for U.S. observers.

2001 and 2002 are good candidates for my poor memory if there were no later outbursts.
For me, in europe, the intense activity that I saw, (still lives with me !) was in the early hours (2-4 utc/local ), there were often several bright meteors 'in flight' at the same time and there were several fireballs out of direct vision that illuminated the surrounding hills. I say 'out of direct vision' to liken to fireworks or, (god forbid,,) explosions when one expects to hear a follow-up 'bang' ! (none did but the visuals were spectacular!)

[Anthony Barreiro]

It is difficult to make conclusions based on observations of Jupiter made every Earth year. The average synodic period of Jupiter (i.e. time between oppositions) is ~399 days. The last two oppositions of Jupiter (late 2011 & 2012) were separated by ~35° in ecliptic longitude. On average, there are 10.86 synodic periods within one Jovian orbital period, meaning that the average movement of Jupiter between oppositions would be more like 33° in ecliptic longitude. So, I'd say that the Earth's own orbit has as much of an effect on the apparent position of Jupiter, as does the eccentricity of Jupiter's orbit.

Thanks, I knew I could count on somebody here to understand the additional complexity of Earth's orbit in this system. 30 degrees is pretty close to 33 degrees for a casual observer, and certainly close enough to check whether Jupiter was in Pisces or Taurus last year. I enjoy rules of thumb, but I honestly don't know the angular dimension of my own thumb as well as some people do.

[Anthony Barreiro]

FYI, intense Leonid activity occurred in 1998-2002. 2001 and 2002 were the best years for U.S. observers.

2001 and 2002 are good candidates for my poor memory if there were no later outbursts.
For me, in europe, the intense activity that I saw, (still lives with me !) was in the early hours (2-4 utc/local ), there were often several bright meteors 'in flight' at the same time and there were several fireballs out of direct vision that illuminated the surrounding hills. I say 'out of direct vision' to liken to fireworks ( or, god forbid,,) explosions when one expects to hear a follow-up 'bang' ! (none did but the visuals were spectacular!)

During the Leonids in 2001 I came home from a late night of carousing and was overwhelmed by the most intense meteor storm I've ever seen. At the time I was living on a hill on the edge of the city, above the streetlights, and across the street from a park with little lighting. The whole sky was full of meteors.

[Nitpicker]

2013gemfreq.gif

This is the activity I've seen over the last four nights. This is from video observations, so only meteors brighter than mag 2 are recorded (probably mag 1 given the bright moon). So figure visual rates were 3-5 times higher.

The Geminids do tend to produce quite a few fireballs.

That is quite amazing and very impressive data gathering, Chris. I was busy observing the Moon from 12:30 to 13:30 UT (22:30 to 23:30 my time) on Dec 14, during the landing of Chang'e 3. (Not that I was expecting to see the landing, I just thought it might be moving to ponder the whole event while observing the Bay of Rainbows live.) But I was also trying to keep one eye open for meteors. I know your graph shows a big drop off at that time, but I'm imagining that might have something to do with your morning twilight. Maybe my eyes were too dazzled by the bright Moon, or maybe the clouds had bad timing in my area, or maybe I'm just not very observant, but I'm sorry to say I didn't see a single meteor over the last three nights. I will keep trying.

[Anthony Barreiro]

2013gemfreq.gif

This is the activity I've seen over the last four nights. This is from video observations, so only meteors brighter than mag 2 are recorded (probably mag 1 given the bright moon). So figure visual rates were 3-5 times higher.

The Geminids do tend to produce quite a few fireballs.

That is quite amazing and very impressive data gathering, Chris. I was busy observing the Moon from 12:30 to 13:30 UT (22:30 to 23:30 my time) on Dec 14, during the landing of Chang'e 3. (Not that I was expecting to see the landing, I just thought it might be moving to ponder the whole event while observing the Bay of Rainbows live.) But I was also trying to keep one eye open for meteors. I know your graph shows a big drop off at that time, but I'm imagining that might have something to do with your morning twilight. Maybe my eyes were too dazzled by the bright Moon, or maybe the clouds had bad timing in my area, or maybe I'm just not very observant, but I'm sorry to say I didn't see a single meteor over the last three nights. I will keep trying.

I was looking at Jupiter last night. I didn't see a single meteor naked eye, but while I was using Procyon to collimate my telescope about 2300 local time several faint meteors were flying through the eyepiece every minute!

[Nitpicker]

I was looking at Jupiter last night. I didn't see a single meteor naked eye, but while I was using Procyon to collimate my telescope about 2300 local time several faint meteors were flying through the eyepiece every minute!

Not sure if you are joking or not Anthony. Sounds like a tall story on first reading. Could it have been stray starlight from Procyon whilst collimating?

[Anthony Barreiro]

I was looking at Jupiter last night. I didn't see a single meteor naked eye, but while I was using Procyon to collimate my telescope about 2300 local time several faint meteors were flying through the eyepiece every minute!

Not sure if you are joking or not Anthony. Sounds like a tall story on first reading. Could it have been stray starlight from Procyon whilst collimating?

No, they were distinct meteors, all traveling from the Geminid radiant. It only took a few minutes to fine tune my collimation, and during this time there were about ten or twelve meteors, I would guess about seventh or eighth magnitude. I just got lucky and pointed my telescope at the right place during the right time.

[Nitpicker]

No, they were distinct meteors, all traveling from the Geminid radiant. It only took a few minutes to fine tune my collimation, and during this time there were about ten or twelve meteors, I would guess about seventh or eighth magnitude. I just got lucky and pointed my telescope at the right place during the right time.

Wow! Lucky you.

[Chris Peterson]

No, they were distinct meteors, all traveling from the Geminid radiant. It only took a few minutes to fine tune my collimation, and during this time there were about ten or twelve meteors, I would guess about seventh or eighth magnitude. I just got lucky and pointed my telescope at the right place during the right time.

Telescopic meteors aren't all that uncommon, but seeing so many is extremely uncommon - unprecedented, even. Most curious. Since you were collimating, I assume you were at a high magnification?

[Anthony Barreiro]

No, they were distinct meteors, all traveling from the Geminid radiant. It only took a few minutes to fine tune my collimation, and during this time there were about ten or twelve meteors, I would guess about seventh or eighth magnitude. I just got lucky and pointed my telescope at the right place during the right time.

Telescopic meteors aren't all that uncommon, but seeing so many is extremely uncommon - unprecedented, even. Most curious. Since you were collimating, I assume you were at a high magnification?

113x with a 0.725 degree field of view.