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Re: [Comet-Images] Re: C/2010 X1

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  • Alan Watson
    Gidday all, This comet is still detectable in STEREO HI2A images up to 20111009. Small, more diffuse than an asteroid in this imager The lower limit for this
    Message 1 of 21 , Oct 11, 2011
      Gidday all,
      This comet is still detectable in STEREO HI2A images up to 20111009. Small, more diffuse than an asteroid in this imager
      The lower limit for this imager is about mag10-11 more in IR spectrum.There should be a delectable moving diffuse object.
      It was detected at lower mags on the way in?? May when its in a better position for visual detection.
       
      Kind regards, Alan Watson.


       
      On Tue, Oct 11, 2011 at 8:48 PM, gvnn64@... <gvnn64@...> wrote:
       

      We updated our blog with some news about our recovery attempts on C/2010 X1 (Elenin): http://bit.ly/o5OvFq
      Bye,
      Giovanni, Nick and Ernesto




      --
      Kind regards, Alan
    • gvnn64@libero.it
      Hello Alan. ... I have seen the object you are referring to in STEREO HI2A images. Can you determine how close it is to the MPC ephemerids? Thanks, Giovanni
      Message 2 of 21 , Oct 12, 2011
        Hello Alan.

        > This comet is still detectable in STEREO HI2A images up to 20111009. Small,
        > more diffuse than an asteroid in this imager

        I have seen the object you are referring to in STEREO HI2A images.
        Can you determine how close it is to the MPC ephemerids?

        Thanks,
        Giovanni Sostero
      • Juan José González Suárez
        Three days ago, I posted a visual observation made on the last available night without moonlight interference : C/2010 X1 (Elenin): 2011 Oct. 9.20 UT: m1=10.7,
        Message 3 of 21 , Oct 12, 2011
          Three days ago, I posted a visual observation made on the last available
          night without moonlight interference :

          C/2010 X1 (Elenin):
          2011 Oct. 9.20 UT: m1=10.7, Dia.=6', DC=1/,
          Tail: 0.2 deg. in PA 310 deg, 20 cm SCT (77x).
          [ The coma appears large and very diffuse,
          without central condensation. Observation made from
          mountain location under very good seeing conditions.
          Nearby field stars checked in DSS. Zodiacal light.
          Altitude: 23 deg.].

          At this point, it is useful to provide additional information.

          We are again speaking about one of these "problematic, extremely diluted
          and fuzzy comets" ...

          But for me this case wasn't problematic or near the threshold of
          visual detection. It was a clear observation ( the atmospheric
          conditions in the Cantabrian Mountains were near optimal down to the
          line of horizon ) made in the course of a short observing session ( 1
          hour approx. ) between moonset and the beginning of the morning
          astronomical twilight. Under such very good conditions, and besides
          C/2010 X1, my plan was to observe another four comets ( C/2010 G2,
          C/2011 S2, 49P, and 45P at low altitude ), so I only could dedicate
          approx. 10 min to the observation and magnitude estimate of C/2010 X1,
          at low magnification as necessary. I didn't check for the motion, given
          the short time-interval and the apparent lack of central condensation in
          such a large ( 6' ) coma. The geometric center of this coma was close to
          the MPC ephemeris position, with an error bar of +/- 4'.

          Best regards and clear skies,


          J. J. Gonzalez

          ( P.S.: as previously told, I don't like to discuss again on the
          diversity among CCD and visual observations ... ).


          ------------------------------------------------------------

          Alan Watson wrote:

          > Gidday all,
          > This comet is still detectable in STEREO HI2A images up to 20111009.
          > Small, more diffuse than an asteroid in this imager
          > The lower limit for this imager is about mag10-11 more in IR
          > spectrum.There should be a delectable moving diffuse object.
          > It was detected at lower mags on the way in?? May when its in a better
          > position for visual detection.
          >
          > Kind regards, Alan Watson.
        • Alan Watson
          ... Gidday Giovanni, Sorry I can t do all the maths necessary to determine this. This is how I work, I have STarry night pro-plus and use the comet data it
          Message 4 of 21 , Oct 12, 2011
            On Wed, Oct 12, 2011 at 7:19 PM, gvnn64@... <gvnn64@...> wrote:
             
            I have seen the object you are referring to in STEREO HI2A images.
            Can you determine how close it is to the MPC ephemerids?
             
             Gidday Giovanni, Sorry I can't do all the maths necessary to determine this.
            This is how I work, I have STarry night pro-plus and use the comet data it downloads from the MPEC guys.
            The STEREO satellites behave like asteroids with circular orbits, so this allows me to have them included into the asteroid data.
            I can position the point of view in starry night to sit very close to each STEREO satellite and look sun wards.
            I make minor adjustments using the star fields in starry night. It is generally very close to the STEREO FOV.
            Here is a starry night movie of the current STEREOA HI2 FOV , zoomed in a little. Elenin and 45P can be seen, they are in good position compared with the actual FOV.
             
            I have used GRAS , but have a problem with PAYPAL, so not signed up at this time. Not really wanting to tell you guys how to operate. I used the MPC ephemerids generator at 15min steps, this usually let me get a comet in a GRAS FOV. So perhaps a stepped set of images moving forward in the orbit may detect it. It seems to be moving quite fast.
             
            Kind regards, Alan Watson.
          • Ian Musgrave & Peta O'Donohue
            G Day All You can use the Horizons email server to get the position of X1 as seen from STEREO A, then compare the STEREO A images with the Horizons ephemeris;
            Message 5 of 21 , Oct 12, 2011
              G'Day All

              You can use the Horizons email server to get the position of X1 as
              seen from STEREO A, then compare the STEREO A images with the
              Horizons ephemeris; Here's a example I used a while back for Encke,
              make sure that the body of the email has no extraneous material (no
              sigs etc.) Comet Elenin is just above the lower travel limit of the
              GRAS scopes at astronomical twilight, so a systematic search with
              narrow field instruments is going to be hard. I might try a long
              exposure with the widefield instrument tonight. If the universe lets me.

              send to : horizons@...
              Subject: JOB C/2009 02 Stereo A

              !$$SOF
              EMAIL_ADDR = ' '
              COMMAND= 'C/2009 O2'
              OBJ_DATA = 'YES'
              MAKE_EPHEM = 'YES'
              TABLE_TYPE = 'OBS'
              CENTER = '500@stereo-a'
              START_TIME = '2010-MARCH-27 8:09'
              STOP_TIME = '2010-APRIL-25 8:09'
              STEP_SIZE = '12 hours'
              QUANTITIES = '1,2,9'
              REF_SYSTEM = 'J2000'
              CAL_FORMAT = 'CAL'
              APPARENT = 'AIRLESS'
              TIME_ZONE = '+09:30'
              RANGE_UNITS = 'AU'
              CSV_FORMAT = 'YES'
              !$$EOF

              Eh, I just did it, here's the STEREO A centric ephemeris for Elenin
              for Oct 9, in the time steps of the STEREO imager.

              *********************************************************************************************************
              Date_(ZONE)_HR:MN, , ,R.A._(ICRF/J2000.0), DEC_(ICRF/J2000.0),
              R.A._(a-app), DEC_(a-app), T-mag, N-mag,
              *********************************************************************************************************
              $$SOE
              2011-Oct-09 00:09, , ,22 36 57.07,-07 32 09.8, 22 36 56.05,-07 32
              15.6, 9.96, 15.25,
              2011-Oct-09 02:09, , ,22 37 30.16,-07 28 43.0, 22 37 29.14,-07 28
              48.8, 9.97, 15.26,
              2011-Oct-09 04:09, , ,22 38 03.20,-07 25 16.3, 22 38 02.18,-07 25
              22.1, 9.98, 15.26,
              2011-Oct-09 06:09, , ,22 38 36.19,-07 21 49.7, 22 38 35.17,-07 21
              55.5, 9.99, 15.26,
              2011-Oct-09 08:09, , ,22 39 09.14,-07 18 23.2, 22 39 08.12,-07 18
              29.0, 10.00, 15.27,
              2011-Oct-09 10:09, , ,22 39 42.04,-07 14 56.8, 22 39 41.02,-07 15
              02.6, 10.01, 15.27,
              2011-Oct-09 12:09, , ,22 40 14.89,-07 11 30.4, 22 40 13.88,-07 11
              36.2, 10.02, 15.28,
              2011-Oct-09 14:09, , ,22 40 47.69,-07 08 04.2, 22 40 46.68,-07 08
              10.0, 10.03, 15.28,
              2011-Oct-09 16:09, , ,22 41 20.45,-07 04 38.1, 22 41 19.44,-07 04
              43.9, 10.04, 15.28,
              2011-Oct-09 18:09, , ,22 41 53.16,-07 01 12.1, 22 41 52.15,-07 01
              17.9, 10.05, 15.29,
              2011-Oct-09 20:09, , ,22 42 25.82,-06 57 46.1, 22 42 24.82,-06 57
              52.0, 10.06, 15.29,
              2011-Oct-09 22:09, , ,22 42 58.44,-06 54 20.3, 22 42 57.43,-06 54
              26.1, 10.07, 15.30,
              $$EOE
              *********************************************************************************************************



              Cheers! Ian
              At 09:50 AM 13/10/2011, you wrote:


              >On Wed, Oct 12, 2011 at 7:19 PM,
              ><mailto:gvnn64@...>gvnn64@...
              ><<mailto:gvnn64@...>gvnn64@...> wrote:
              >
              >I have seen the object you are referring to in STEREO HI2A images.
              >Can you determine how close it is to the MPC ephemerids?
              >
              >
              > Gidday Giovanni, Sorry I can't do all the maths necessary to determine this.
              >This is how I work, I have STarry night pro-plus and use the comet
              >data it downloads from the MPEC guys.
              >The STEREO satellites behave like asteroids with circular orbits, so
              >this allows me to have them included into the asteroid data.
              >I can position the point of view in starry night to sit very close
              >to each STEREO satellite and look sun wards.
              >I make minor adjustments using the star fields in starry night. It
              >is generally very close to the STEREO FOV.
              >Here is a starry night movie of the current STEREOA HI2 FOV , zoomed
              >in a little. Elenin and 45P can be seen, they are in good position
              >compared with the actual FOV.
              > <http://flic.kr/p/avknw1>http://flic.kr/p/avknw1
              >
              >I have used GRAS , but have a problem with PAYPAL, so not signed up
              >at this time. Not really wanting to tell you guys how to operate. I
              >used the MPC ephemerids generator at 15min steps, this usually let
              >me get a comet in a GRAS FOV. So perhaps a stepped set of images
              >moving forward in the orbit may detect it. It seems to be moving quite fast.
              >
              >Kind regards, Alan Watson.
              >
              >
              >

              ======================================================
              Ian Musgrave Peta O'Donohue, Jack Francis, Michael James and Andrew
              Thomas Musgrave
              reynella@... http://home.mira.net/~reynella/
              Southern Sky Watch http://www.abc.net.au/science/space/default.htm
              (scroll down right hand menu)
              AstroBlogg http://astroblogger.blogspot.com/
              Contributing Editor, Sky & Space
              http://www.skyandspace.com.au/public/home.ehtml
            • gvnn64
              Hi Alan, thanks for yours explanation and movie link. Now I realized that what I have seen in the STEREO animatiom was actually comet 45P, and not C/2010 X1
              Message 6 of 21 , Oct 13, 2011
                Hi Alan,
                thanks for yours explanation and movie link. Now I realized that what I have seen in the STEREO animatiom was actually comet 45P, and not C/2010 X1 (Elenin)!
                Bye,
                Giovanni

                --- In Comet-Images@yahoogroups.com, Alan Watson <c2009a1@...> wrote:
                >
                > On Wed, Oct 12, 2011 at 7:19 PM, gvnn64@... <gvnn64@...> wrote:
                >
                > >
                > > I have seen the object you are referring to in STEREO HI2A images.
                > > Can you determine how close it is to the MPC ephemerids?
                > >
                >
                > Gidday Giovanni, Sorry I can't do all the maths necessary to determine
                > this.
                > This is how I work, I have STarry night pro-plus and use the comet data it
                > downloads from the MPEC guys.
                > The STEREO satellites behave like asteroids with circular orbits, so this
                > allows me to have them included into the asteroid data.
                > I can position the point of view in starry night to sit very close to each
                > STEREO satellite and look sun wards.
                > I make minor adjustments using the star fields in starry night. It is
                > generally very close to the STEREO FOV.
                > Here is a starry night movie of the current STEREOA HI2 FOV , zoomed in a
                > little. Elenin and 45P can be seen, they are in good position compared with
                > the actual FOV.
                > http://flic.kr/p/avknw1
                >
                > I have used GRAS , but have a problem with PAYPAL, so not signed up at this
                > time. Not really wanting to tell you guys how to operate. I used the MPC
                > ephemerids generator at 15min steps, this usually let me get a comet in a
                > GRAS FOV. So perhaps a stepped set of images moving forward in the orbit may
                > detect it. It seems to be moving quite fast.
                >
                > Kind regards, Alan Watson.
                >
              • Ian Musgrave & Peta O'Donohue
                G Day All ... 4 x 120 second exposures with the wide field GRAS 14 instrument showed nothing when stacked, neither did 5x120 sec exposures on the narrow field
                Message 7 of 21 , Oct 13, 2011
                  G'Day All

                  At 10:51 AM 13/10/2011, I wrote:
                  >I might try a long exposure with the widefield instrument tonight.
                  >If the universe lets me.

                  4 x 120 second exposures with the wide field GRAS 14 instrument
                  showed nothing when stacked, neither did 5x120 sec exposures on the
                  narrow field GRAS 05 when stacked. Still a lot of Moonlight interference.

                  Cheers! Ian

                  ======================================================
                  Ian Musgrave Peta O'Donohue, Jack Francis, Michael James and Andrew
                  Thomas Musgrave
                  reynella@... http://home.mira.net/~reynella/
                  Southern Sky Watch http://www.abc.net.au/science/space/default.htm
                  (scroll down right hand menu)
                  AstroBlogg http://astroblogger.blogspot.com/
                  Contributing Editor, Sky & Space
                  http://www.skyandspace.com.au/public/home.ehtml
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