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Re: [comets-ml] Hello from new member

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  • Alan Hale
    Hi everyone, Many thanks for the warm welcome from the folks here, both to those who posted here publicly and those who wrote me privately. You ll be hearing
    Message 1 of 8 , Jan 4, 2007
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      Hi everyone,

      Many thanks for the warm welcome from the folks here, both to those who
      posted here publicly and those who wrote me privately. You'll be hearing
      more from me from time to time . . .


      C/2006 P1 is still being elusive from these parts. We had relatively clear
      skies here last night, and I made attempts both after sunset and before
      sunrise. I have an excellent near-horizon evening sky site that's not too
      far away, but unfortunately there was a band of very distant cirrus low in
      the west at the inopportune time -- although I'm not sure how much effect
      this actually had. The conditions were even better this morning, but I don't
      have an easily accessible site with as good a view to the eastern horizon.
      It looks like we're still a few days away before the comet becomes
      accessible from this latitude.


      Sincerely,

      Alan
    • Alan Hale
      Hi everyone, After several unsuccessful attempts over the past week, I finally succeeded in observing this object this evening. My observing site was slightly
      Message 2 of 8 , Jan 8, 2007
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        Hi everyone,

        After several unsuccessful attempts over the past week, I finally succeeded
        in observing this object this evening. My observing site was slightly south
        of Cloudcroft, New Mexico, along the highway that leads to the National
        Solar Observatory at Sacramento Peak (and also where the Sloan Digital Sky
        Survey is being conducted). Elevation is 2690 meters, and to the west the
        site overlooks the desert floor some 1370 meters lower. (This gives a
        depressed horizon about one degree or so below the horizontal.) The sky was
        clear, with a bit of haze over the desert close to the horizon. Latitude of
        the site is 32d 57' North.

        I saw the comet briefly for two or three minutes beginning around 0:37 UT (a
        little over 20 minutes after sunset, comet's elevation just over 3 degrees).
        I was using a 20 cm SCT at 78x. The comet appeared as a bright central
        condensation, with the beginnings of a tail towards the northeast.
        Unfortunately, I lost the comet after those two to three minutes and
        couldn't get it back.

        Hard to make a formal magnitude measurement; the only comparison object of
        any kind nearby was Venus, which was much brighter than the comet. In 1976 I
        first picked up Comet West in the evening sky about three days before
        perihelion when it was at a similar elongation (although more due east of
        the sun and thus a bit higher in the sky) -- the magnitude was perhaps -1,
        and it was easy in 10x50 B. Comet McNaught this evening did not appear to be
        that bright; based primarily upon that long-ago observation of West, I'd
        "guesstimate" McNaught's magnitude as around 0, perhaps in the range of 0 to
        1.

        Of course, my latitude here, and the comet's correspondingly low altitude in
        a bright sky, renders it quite a bit less spectacular than it might be for
        observers further north. (Some of the images I've seen from northern
        observers are absolutely spectacular!) If the comet keeps on behaving as it
        has been, you folks in the southern hemisphere should get quite a show later
        this month.

        The extended weather forecast here is predicting clear weather for pretty
        much the rest of this week, so I'm going to be attempting observations just
        about every evening that I can.


        Sincerely,

        Alan
      • Selina Phanara
        I live in Los Angeles and I work at Griffith Observatory, I am not an astronomer but am very interested in seeing C/2006-P1 so I took a knowledgable co
        Message 3 of 8 , Jan 8, 2007
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          I live in Los Angeles and I work at Griffith Observatory, I am not an astronomer but am very interested in seeing C/2006-P1 so I took a knowledgable co worker's advice and decided to go to the beach to see what I could see. LA is pretty smoggy with the high winds right now.
          After all I can read at the beach and wait for sunset just as well as on the couch.
          I took Malibu canyon instead of Topanga because it's swifter.
          I hung out at a little place on PCH called Malibu Seafood and got VERY annoyed because there was this big black smoke cloud creeping up on my horizon just before sunset.
          Just my luck.
          I thought the smog was going to be a problem.
          Malibu took this opportunity to catch on fire. BIG fire too.
          I didn't see the comet and am now just home after detouring up the 1 to the 101 in Oxnard to get back to Burbank.
          Ha!
          I did have time to read though. It was a good day despite the huge black clouds of smoke.
          Maybe tomorrow!



          *¨) ¤
          .•´ .•*¨) .•*•. *
          (¸.•Selina•*¸ ¤
          .•´ .•´¤ ¸•*
          (¸.•* (¸.•








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        • Maciej Reszelski
          ... Congratulations Alan! You are on lucky place. My forecast shows rainshowers every day with maybe lucky clear moments.... Best regards, Maciej
          Message 4 of 8 , Jan 9, 2007
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            >The extended weather forecast here is predicting clear weather for pretty
            >much the rest of this week, so I'm going to be attempting observations just
            >about every evening that I can.

            Congratulations Alan!

            You are on lucky place. My forecast shows rainshowers every day with
            'maybe' lucky clear moments....


            Best regards,
            Maciej
          • gmike@cstone.net
            Congratulations to all who are making the effort to observe this fabulous sight. Many thanks to Rob & Siding Spring for being there to find this comet. I had
            Message 5 of 8 , Jan 9, 2007
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              Congratulations to all who are making the effort to observe this fabulous
              sight. Many thanks to Rob & Siding Spring for being there to find this
              comet.

              I had to work too many hours last week to be able to get out and observe,
              but that changed this week, along with a change in weather yesterday for
              the better.

              I observe from the northern end of the Blue Ridge Parkway/southern end of
              Shenandoah Natl. Park in Virginia, USA, latitude 38.1N at an altitude of
              ~650m. I observed C/2006 P1 from 2245-2305 Jan. 8 (evening) and 1155-1205
              Jan. 9 (morning). The evening observing conditions are far better, with
              the comet several degrees higher in the sky. Murk near the horizon has
              prevented me from seeing the comet with my naked eye, but it is quite
              beautiful in 10x20 binoculars, showing 1+ degree-long tail.

              Good luck to everyone in the Northern Hemisphere in their observing
              attempts over the next few days, and I'm looking forward to reports from
              the other half of the world the rest of the month...

              Michael Doyle
              Charlottesville, Virginia, USA
            • Alan Hale
              Hi everyone, ... Well, so much for weather forecasts you hear on the radio :( Tuesday: clear (except clear to the lay person doesn t necessarily mean the
              Message 6 of 8 , Jan 11, 2007
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                Hi everyone,

                >
                > The extended weather forecast here is predicting clear weather for pretty
                > much the rest of this week, so I'm going to be attempting observations just
                > about every evening that I can.
                >

                Well, so much for weather forecasts you hear on the radio :(

                Tuesday: "clear" (except "clear" to the lay person doesn't necessarily mean
                the same thing as "clear" to us astronomy types). Thick band of cirrus in
                the west after sunset, right in the comet's location. I still tried, but no
                success.

                Wednesday: cirrus during the day, then storm moved in beginning around
                sunset. (It rained here last night -- unusual for the mountains in January)

                Thursday (tonight): The storm has moved east, but residual moisture in the
                atmosphere kept the sky overcast over the mountains and the desert.

                Yet another storm is supposed to move in tomorrow, and be with us for at
                least two days.


                You win some, you lose some . . .

                It appears my two-minute observation on Monday night will probably do it for
                this comet for me. (I did follow it in the evening sky from mid-September
                through mid-November, when it was much fainter.) Thanks to all those who
                took such splendid images, and let's hope those of you in the southern
                hemisphere have more cooperative weather than I had.


                Sincerely,

                Alan
              • Alan Hale
                Hi everyone, It looks like I was a little too pessimistic in my post last night. While we continue to have moisture streaming in from the southwest, the
                Message 7 of 8 , Jan 12, 2007
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                  Hi everyone,

                  It looks like I was a little too pessimistic in my post last night. While we
                  continue to have moisture streaming in from the southwest, the western ridge
                  of the Sacramento Mountains has been acting like a cloud-break, and has been
                  creating a hole in the cloud cover over the eastern slope where I'm located.
                  We had beautiful blue sky for a good part of the day today.

                  I was easily able to locate the comet in broad daylight with a 20 cm SCT,
                  and followed it off and on for almost three hours around local noon. Very
                  bright central condensation, with a wisp of tail.

                  This is my second daylight comet, and my first for the middle of the day. On
                  one morning in March 1997 I was able to follow Hale-Bopp telescopically just
                  past sunrise. I probably would also have picked up West in daylight on the
                  day of its perihelion passage, but I was on the high-school track team and
                  had after-school practice; I arrived at my observing site just after sunset
                  and picked up the comet almost right away in binoculars, and could also see
                  it with the naked eye without much difficulty.

                  This evening, I drove about an hour's drive east, trying to put as much
                  distance as I could between the clouds along the western ridge and me. I
                  succeeded; while I did have a band of clouds almost five degrees high along
                  the western horizon, I was able to pick up the comet in 12x50 binoculars
                  (and also with the 20 cm scope) about five minutes before it got swallowed
                  up in the clouds. Impressive sight in the binoculars, with about one degree
                  of tail to the northeast. I couldn't convince myself I could see the comet
                  with the naked eye, but I'd like to think I would've done so if I could have
                  had an extra five minutes for the sky to get a bit darker.

                  Brightness measurement: I've been following the discussions here, and I
                  think we all have to admit that measuring comets' brightnesses in these
                  kinds of conditions is a bit problematical, especially considering the lack
                  of suitable comparison objects, the varying sky brightness, and so on. Here
                  is my stab at it:

                  During my daytime observation today I tried, without success, to find the
                  comet with the 12x50 binoculars, even though I pretty much knew where to
                  look. I can almost always find Venus with binoculars in the daytime if I
                  sweep the general area -- thus, (to me, anyway) the comet is clearly fainter
                  than Venus. On the other hand, based upon other objects I've telescopically
                  viewed during the daytime, the comet can be no fainter than magnitude -2.
                  (For what it's worth, before dawn on the morning I followed Hale-Bopp past
                  sunrise I had measured its brightness as 0.2; that of course, refers to the
                  entire coma, not just the central regions as is the case with McNaught
                  today, so this is a bit of an apples-vs.-oranges comparison. Nevertheless,
                  McNaught was clearly brighter than Hale-Bopp was then.)

                  My perihelion day observation of West in 1976 was under similar geometry and
                  conditions (although better weather conditions) as this evening's McNaught
                  observation. To me, McNaught was clearly *not* as bright as West was on that
                  occasion. My original estimate for West that evening was -1.5, but I was
                  quite new to the comet magnitude game at that time, and that was almost
                  certainly an underestimate; if I remember correctly, John Bortle viewed it
                  that same evening and called it magnitude -3, and that strikes me as being
                  more accurate. McNaught would thus be somewhat fainter than -3, by this
                  approach.

                  The upshot, with the understanding that there's a lot of hand-waving
                  involved: my brightness measurement for today is -2.5 +/- 0.5. The daytime
                  observation was at January 12.80 UT (20 cm SCT); my measurement this
                  evening, based upon even more hand-waving, would be -2: with 12x50 B at
                  January 13.02 UT.

                  FWIW, I tried the sunglasses bit during the daytime observation today. My
                  impression was that there wasn't much difference one way or the other.


                  I hope to try again tomorrow, especially with the predicted forward
                  scattering maximum. The forecast is calling for more rain, but we'll see . .
                  .


                  Sincerely,

                  Alan
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