Comet C/2009 P1 (Garradd) in 2011

C/2009 P1 (Garradd)

Comet Garradd is expected to brighten to magnitude 10 at the beginning of July. For southern hemisphere viewers it will then rise in the late evening and be best observed in the morning sky before sunrise. As it brightens further during the following weeks it will also rise earlier to become an evening object by August.

Garrard will be north of the celestial equator and so have only a moderate altitude from New Zealand, getting lower during the following months. By the end of October it will be setting at about 9.30 pm and be very low by the time the sky darken following sunset. It will be lost to view a few days later.

The comet will continue to brighten during the rest of 2011 and into 2012, when it should reach magnitude 7.1 by February. It will also continue to move north, so that by 2012 it will rise only in the extreme north of New Zealand.

The comet was discovered by Gordon Garradd at Siding Spring, Australia in August 2009.

Chart showing the path of Garradd during July and early August 2011.

The chart is a southern hemisphere view with north at the bottom and east to the right.
Stars to magnitude 7.50 are shown, with magnitudes labelled for sars brighter than magnitude 5.0.
The circle on the chart represents a field of view 5° in diameter, a fairly typical field of view for binoculars.

Path Garradd.

Chart showing the path of Garradd from mid August to November 2011.

Path Garradd.

Chart prepared using GUIDE 8.0. Program produced by Project Pluto.

Positional data for C/2009 P1 (Garradd) from July to November 2011.

The table shows the position of the comet , its distance in AU from the Sun and Earth, its magnitude, elongation from the Sun, the constellation it is in and the approximate rise time at Wellington. Times will differ by a few minutes at other places in NZ.

      Date         RA      Dec    Sun    Earth   Mag   Elong   Con    Rise
                hr min    deg  '   AU     AU            deg            pm
    1 Jul 2011  22 42.7   +02 29  2.759  2.163  10.1    115.8  Aqr   10.33 pm
    8 Jul 2011  22 32.9   +04 24  2.693  1.996   9.8    123.5  Peg   10.03 pm
   15 Jul 2011  22 20.6   +06 25  2.625  1.843   9.5    131.1  Peg    9.30 pm
   22 Jul 2011  22 04.9   +08 37  2.558  1.705   9.2    138.7  Peg    8.54 pm
   29 Jul 2011  21 44.8   +10 54  2.492  1.588   9.0    145.4  Peg    8.15 pm
    5 Aug 2011  21 21.3   +13 09  2.426  1.498   8.7    149.3  Peg    7.33 pm
   12 Aug 2011  20 54.7   +15 14  2.361  1.435   8.5    148.7  Del    6.47 pm
   19 Aug 2011  20 26.1   +16 58  2.297  1.404   8.3    143.3  Del    5.57 pm
                                                                      Set    
   26 Aug 2011  19 57.1   +18 13  2.233  1.403   8.2    134.8  Sge    2.56 am
    2 Sep 2011  19 29.6   +18 59  2.171  1.429   8.1    125.0  Sge    1.58 am
    9 Sep 2011  19 04.8   +19 19  2.110  1.477   8.1    115.0  Sge    1.04 am
   16 Sep 2011  18 43.6   +19 20  2.051  1.542   8.1    105.3  Her   12.16 am 
   23 Sep 2011  18 26.1   +19 10  1.993  1.617   8.0     96.2  Her   11.31 pm
   30 Sep 2011  18 11.9   +18 55  1.938  1.697   8.0     87.8  Her   11.51 pm NZDT
    7 Oct 2011  18 00.8   +18 39  1.885  1.778   8.0     80.1  Her   11.13 pm
   14 Oct 2011  17 52.3   +18 27  1.834  1.857   8.0     73.1  Her   10.38 pm
   21 Oct 2011  17 45.8   +18 20  1.787  1.929   7.9     66.7  Her   10.05 pm
   28 Oct 2011  17 41.1   +18 19  1.743  1.992   7.9     61.0  Her    9.32 pm
    4 Nov 2011  17 37.7   +18 26  1.702  2.045   7.9     56.0  Her    9.01 pm
   11 Nov 2011  17 35.4   +18 42  1.666  2.086   7.8     51.8  Her    8.30 pm
    Garradd will be lost in the evening twilight by mid November

Royal Astronomical Society of New Zealand

The Brighter Comets in 2011: C/2009 P1 (Garradd)

C/2009 P1 (Garradd)

Chart showing the path of Garradd during July and early August 2011.

Chart showing the path of Garradd from mid August to November 2011.

Positional data for C/2009 P1 (Garradd) from July to November 2011.