(meteorobs) Hunter's Moon Orionids

[Bruce McCurdy]

    For the fourth time this week my alarm woke me in the middle of the night, and for the fourth time I looked out my window to heavy clouds. But this time I was determined to make my move regardless:  I had a reliable forecast from both Alister Ling and Mike Noble that clearing was coming from the west before dawn; the Orionid window was slamming shut and with it my project of observing every major meteor shower in the same calendar year; and there was the attraction of the remarkable new Comet Holmes that compelled me to leave my warm bed on a cold Thursday morning. A day before 17P/Holmes was completely unknown to me ... but in that day, it brightened by a factor of ~one million to suddenly achieve naked-eye prominence. More surprising still -- if that's even possible -- the "nova comet" is actually a _recurrent_ nova, having done something similar in 1892, back around the time its namesake (Sherlock) was taking the plunge at Reichenbach Falls, a seemingly catastrophic event from which he too, survived to shine another day.  

    To say the sky looked unpromising for meteor observing is an understatement. The only thing shining through the low cloud was the towering Hunter's Moon, which hours later would be the biggest, baddest Full Moon of 2007. But as I headed for a secondary observing site to the southwest of the city, the back edge of the cloud arched above the western horizon, and by the time I was comfortably ensconced in my sleeping bag and observing chair the skies were opening up as promised. I had positioned myself on the lee side of the car which also shielded me from direct moonlight, and surveyed a most remarkable sky. 

    The Winter Hexagon encircled the ruddy pair of Betelegeuse and Mars, a beacon currently passing through the heart of Gemini.  Leo was rising in the east with two bright visitors, Saturn and Venus, the latter very near its greatest elongation. Yet a third bright constellation renowned for its meteors, Perseus, had just crested through the zenith, and was hosting the most unexpected guest of all, the nearly stellar Comet Holmes. 

    Orion, host of the present meteor shower, was standing straight up in the south. And wouldn't you know it but within a minute the Hunter also had a bright, very brief, visitor, as a first-magnitude meteor flashed near Betelgeuse and dropped right by Mintaka. A true Orionid, my very first of the year, short but very sweet. I feel a special affinity for this of all showers, as the sight of these remnants of Halley's Comet always brings me full circle to my earliest nights as a serious astronomer in the fall of 1985.   

    The goose egg broken, I decided to spend the next hour or so surveying the comet in 10x50 and 15x70 binoculars, describing it on my audiotape as a bright, distinctly yellow doppelganger of the Eskimo Nebula, close to magnitude 2.5, as bright as Mira at its finest. It's tiny circular shell clearly expanded over the course of the 2.5 hours I was out. Before night's end I was already describing it as the Second Great Comet of 2007. Has a nice ring to it, eh?

    By 06:15 MDT the heavy clouds had disappeared entirely, the Moon was sinking in the west, and I decided to do an hour of meteor counting. There was still some cirrusy haze that reduced the limiting magnitude to just a shade better than 5.0, which deteriorated in the last minutes as the eastern horizon brightened. Of course I gazed in the direction of Perseus Plus One, which also enabled me to keep the radiant within my field of view. I was pleasantly surprised to get no fewer than five Orionids within 20 minutes, indicating the radiant still had some life in it well over 3 days past the peak. After that things slowed down with a few sporadics but just one more Orionid and nothing from the other minor radiants. Nonetheless a surprisingly good hour under the moonlit conditions. 

    The standout meteor was the first. I had just turned on my microcassette to give a naked eye description of the comet, so caught my entire reaction on tape: "To the naked ... ohhhh! SWEET!!! Oh, I even had the tape recorder going .... wow. That is unbelievable. Orionid ... it just came, it was like it was right out of the comet!! That's where it started in the sky ... I was just beginning to describe how the comet looks to the naked eye, when a meteor came out of it! and it was an Orionid, it was really faint but it doesn't matter -- I was looking _right_ at it! -- it was maybe fourth magnitude, it was swift and lining up with the radiant, it went up above Mirfak in the general direction of the Double Cluster ... oh my. I was just about to describe how the comet was just a little hint of non-stellar and it suddenly became linear! Wow. ... It was a miraculous meteor, I can't believe it, I was thinking all along if I keep looking at this field I might get a meteor somewhere around the comet, but it was like it came right out of that _point_ on the sky!" 

    A few minutes later (after I thought I had calmed down) I replayed my description and found myself tearing up at what had been a truly remarkable sight, the fiery demise of a particle from that most famous of comets which by chance line of sight had appeared to spark right out of the amazing newcomer. The realization that my cheeks were wet merely served to open the floodgates, and for a minute or two I was overcome with the beauty and wonder of it all.

    Bruce
    *****

Observer: Bruce McCurdy,  MCCBR
Location: Range Rd 264/Sanctuary Rd near Devon, AB @53.371110, -113.787530
Time: 2007 Oct 25, 12:15 - 13:15 UT ; Teff = 1.0 hour
Method: visual, microcassette recorder and talking watch
Limiting magnitude = ~5.1 (SQM = 18.7)

Active radiants:
Northern Taurid (NTA) 02:36 (039) +18
Southern Taurid (STA) 02:40 (040) +12
Orionids (ORI) 06:20 (095) +16
Xi Geminids (XGE) 6:56 (104) +11
Epsilon Geminids (EGE) 07:00 (105) +27


12:15                          start
12:20  ORI    +4       "miraculous" meteor! right out of Comet Holmes!
12:25  ORI    +3       straight up into Auriga, brief wake
12:28  ORI    +3       above Auriga, brief wake
12:32  ORI    +1       passed right thru the Pleiades! long train, persisted ~0.5 s
12:35  ORI    -2        "white fringing to yellow" near Sirius, but brighter; brief wake        
12:44  SPO    +4       dropping between the legs of Perseus, as if radiating _from_ the comet 
12:47  SPO    -1        a "fireworks fizzler" but white; faded and came back; brief train                 
12:59  SPO    +1       peripheral vision
13:00  ORI    +4       white, no train
13:14  SPO    +4       barely visible, fairly near the comet                       
13:15                          end

6 ORI: -2, +1, +3(2), +4(2)
4 SPO: -1, +1, +4 (2)
Total meteors: ten 
***