Sunday, March 16, 2014

Sunday March 16, 2014 - March Meteors Observed in 2007

  After plotting the meteor seen after midnight today, I realized that I'd made an entry in the past about meteors that seemed to radiate from this area of the sky in early March. This morning I started going through old logs and found the record . The observations had been on two consecutive nights; the mornings of March 11 and March 12, 2007. I'd seen a total of three meteors, and when I plotted them on a chart printed off the Heavens-Above website, then extended their paths in the sky backward, all three meteors seemed to converge at a point close to the bright star Arcturus in Bootes. I thought that maybe I was seeing a Minor Meteor Shower at the time. Here's the plot that I made seven years ago ... though after studying materials about visual meteor observing, I realize now that this plot has some issues! I'll describe these also.



  Meteor #1 was seen at 1:35 AM (6:35 UT) on Sunday, March 11, 2007. It was about 1.0 magnitude and fast with no train, and seemed to cross right through Bootes.
  Meteor #2 was seen just one minute after the first one, at 1:36 AM (6:36 UT) Sunday, March 11, 2007. This one was fainter at 3.0 magnitude, fast, and also had no train. It zipped from near the star Arcturus to south of Corona Borealis.
  Meteor #3 was seen the following night at 1:15 AM (5:15 UT) on Monday, March 12, 2007. (Daylight Saving Time had occurred after the first two meteors were observed, hence the difference in UT conversion from one night to the next!) This was a bright meteor of about 1.0 magnitude that was fast with no train, and it zipped from the southern part of Ursa Major all the way to the constellation Gemini.

  Here are the problems with this plot that I made back then. First of all, I realize now that to be really accurate, one has to plot meteor paths on a chart that uses gnomonic projection, like the BRNO Atlas that I've downloaded from the IMO website this year. Secondly, I didn't realize until reading through IMO materials that there's a relationship between the apparent meteor path length and the radiant. From what I understand now, at least for meteors higher than 30 degrees, the distance between the radiant and the start point of a plotted meteor has to be at least twice as long as the meteor path itself. Using this general rule, the first meteor I saw probably originated from a radiant between and south of Virgo and Libra, while the second one probably had a radiant southwest of the brighter stars of Virgo. The third one may have had a radiant as far away as Serpens. Of course I'm still making these estimates using the wrong kind of chart and I'm also assuming that the path lengths of the three that I drew seven years ago are accurate.

  I think now that the first two meteors could have been from the almost-year-long Anthelion source, like last night's meteor may have been. The only problem with this is that I described the speed of all three meteors then as "fast" and Anthelion Meteors are lower in velocity than most other types. It's possible that all three of them were just random Sporadics also.

  If nothing else, going back to this entry from 2007 shows me that my own observing methods for meteors are evolving over time! As the year goes on I hope to get out to do more plotting and counting during the major and minor showers so I can contribute some good data to the IMO. There's still a lot about meteor showers that remains to be discovered. It's a wide-open area of amateur astronomy!

AM Sunday March 16, 2014 - PostScript

  Seeing the meteor tonight in this chilly predawn mid-March sky has prompted my memory a bit ... I know that several years ago I documented a couple of meteors in early or mid March that were also in this part of the sky near the constellations Bootes and Corona Borealis. I'll try to find the notes I made then and publish them here soon. In hindsight these may also have been Anthelion Meteors. It's also possible (but not probable?) that there's a minor meteor shower that's active this time of year. I'll do some note searching and research to see if I can find anything!

AM Sunday March 16, 2014 - Observing Notes - First Meteor of 2014

  Although skies were clear at sunset, afterward for most of the night we had on-and-off scattered high clouds in the area, There were long periods of clear sky and then long periods of scattered high clouds. The Moon was just hours from Full in southern Leo, so it was a bright night. Winds picked up and became gusty after dark and the temperature dropped rapidly. On Saturday we'd been in the mid-50's F but by 1:00 AM we were down to 35 F with a wind chill of 26 F.

  Though I played around a lot with the idea of getting out in the lawn chair to do my first "professional" meteor watch of 2014 to report to the IMO, the scattered high clouds and moonlight discouraged this. I walked out into the back yard several times from evening through after midnight to assess the sky conditions, but whenever I thought the sky was clear and I got motivated to do the meteor watch, I'd go outside fifteen minutes later to find out that more cirrus clouds had drifted in!

  However, the night wasn't a total loss. At 1:09 AM (5:09 UT March 16) I spotted what turned out to be the first meteor I've seen and documented in 2014! It was 2nd magnitude and fairly slow-moving. I spotted it over the roof of our house as it passed from Corona Borealis to Hercules, where it flared out. It left a very brief train in its wake that lasted probably a second or less. I took the time to really note the position in the sky where I saw it begin and end, and the time that I saw it. Then I made careful notes when I was back inside the house.

  The plot below was made from memory using the BRNO Atlas sheet #5. The meteor itself is in the upper left corner with the arrow showing the direction of movement. I also plotted the rough position of the Anthelion Radiant in the far lower right corner, because I'm fairly sure from its slow speed, path length, and direction that this was an Anthelion Meteor that I spotted this morning.


    The sky was so clear after 1:00 AM that I thought about getting out for about an hour again to do the meteor session, but when I went outside just before 2:00 AM high clouds had started to drift in all over the sky again. There was a very impressive bright ring around the Moon that extended through the Sickle of Leo to the eastern edge of Leo and Virgo, and faded away to my south where the tree branches obstructed some of the view.


Saturday, March 15, 2014

PM Saturday March 15, 2014 - Notes

  Full Moon will occur at 17:08 UT March 16, or 1:08 PM EDT tomorrow. The sky has been mostly clear today with scattered high clouds. The ground is totally free of snow cover, and this is the first day since New Years Day that I can't find even a trace of snow in my front or back yard. After a very cold middle of the week it's been mild yesterday and today. Another wave of cold air is forecast for Sunday and Monday. I may get out to do some observing after sunset if conditions are decent in spite of the moonlight.

Thursday, March 6, 2014

Thursday, March 6, 2014 - Brief Notes

  When one observes outside with a telescope that runs off AC power from an outlet on the side of the house, and the patio has been covered with piles of snow for most of the last three months, one ends up doing very little observing! If you measure the winter season as December 1 - February 28, Indianapolis just ended its record snowiest winter in history. It's been more than 30 years since a season this bad; not just with the snowfall, but also the number of nights with below zero (°F) temperatures.

  The good news is that March is here. It started off with a snow and ice event on Sunday the 2nd and a couple of much colder than normal days following it. But as we reach the end of this first full week of March, temperatures are starting to moderate, a lot of the snow is gone, and the urge to get out and do some meaningful amateur astronomy is growing!

  I'm currently researching neglected Eclipsing Binary stars and good spring and summer YSO targets to start regularly observing. I'm also planning to do more meteor shower work and hopefully lunar observing. After a long dormant period, I hope to start getting out under the night sky soon and posting my observations here again.