C/2011 L4 (PANSTARRS)


Observers:      
Karaa = Johan Kärnfelt, Gothenburg, Sweden
KAR02 = Timo Karhula, Virsbo/Vasteras, Sweden
WAR01 = Johan Warell, Skurup, Sweden

The observations are presented in the ICQ visual or CCD report format.
				


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   2011L4  2013 05 10.91  S  8.6 TK  8.0B    11   4    6   0.4  300 ICQ XX WAR01
Comments: Round coma, straight diffuse tail. Coma well condensed, but less so than 
May 1. Comet and comparison stars (mag 8.4VT, 8.6VT, spectral type K5 and K0) at 
altitude 42 deg. Dark sky, nautical night, ZLM 6.6. Calm, +10 C, clear skies. Site: 
Lindby observatory, Skurup, Sweden.




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   2011L4  2013 05 01.88  S  8.0 TK  8.0B    11   5    6/  0.7  335 ICQ XX WAR01
Comments: Round coma, straight tail stretching between PA 330 and 25. Coma somewhat 
less condensed than previously. Comet and comparison stars (mag 7.6VT, 8.4VT, 
spectral type K0 and F0) at altitude 36 deg. Dark sky, ZLM ca 6.6. Calm, +3 C, 
clear skies. Site: Lindby observatory, Skurup, Sweden.




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   2011L4  2013 04 28.90  S  7.5 TK  8.0B    11   5    7   0.4  340 ICQ XX WAR01
Comments: Coma well condensed, round. Brightest and longest part of tail straight, 
in PA 340. Shorter part of tail in PA 320 deg, length 0.2 deg, which sharply marked 
the W edge of the tail. The E edge of the tail fuzzy. Comet and comparison stars 
(mag 7.4VT, 8.0VT, both of  spectral type A0) at altitude 31 deg. Dark sky, ZLM ca 
6.6. Slight breeze, +4 C, 2/8 Ci or As approaching from W. Site: Lindby observatory, 
Skurup, Sweden.




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   2011L4  2013 04 18.91  S  6.7 TK  8.0B    11   5    8   0.4  345 ICQ XX WAR01
Comments: Coma well condensed, round. Tail straight, diffusing faintly out to E 
and W from the main direction of the tail, in a 30 deg wide fan. Comet and 
comparison stars altitude 23 deg. Bright moon, ZLM ca 5. Clear sky, +8 C. Site: 
Lindby observatory, Skurup, Sweden.


				
				
Comet      Date (UT)     MM Mag Ref Aper Type x  dia  DC taildg tailpa  Observer
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   2011L4  2013 04 08.90 $S  5.5 TK  5.0B     7        8   0.8  355 ICQ XX WAR01
   2011L4  2013 04 08.90             8.0B    11        8   1.3  355 ICQ XX WAR01
Comments: Appearance of comet very similar to previously though it has decreased in
brightness. Tail straight, more sharply defined to W, diffuse and fan shaped toward
E ending in approx PA 050. Tail appears longer than previously. Very small, well
condensed coma. In 11x80B, tail length 1.3 deg and starlike CC approx mag 8. Comet
at alt 12.0 deg. Comp stars HD2421 (5.19VT, A2, alt 10.5), 22 And (5.07VT, F2, alt
11.8), HD 1279 (5.84VT, B7, alt 13.8). Comet slightly brighter than HD 2421, 
considerably fainter than 22 And, considerably brighter than HD 1279. Site: Lindby 
observatory, Skurup, Sweden.



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   2011L4  2013 04 06.08  B  5.0 TK  5.0B    18   3    7/  1.9  355 ICQ XX KAR02
Comment:  My first morning observation of comet PanSTARRS.  Comet and even its tail 
still visible naked eye which appeared about 1.0 deg long. In the same binocular 
field of view as M31 which appeared sligthly fainter than the comet. Altitude 22º, 
solar altitude -15º. Temperature -9º C. Observing site:  Vasteras, Sweden.



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   2011L4  2013 04 03.85 $S  4.6 TK  5.0B     7        8   1.0  355 ICQ XX WAR01
Comments: Nothing much has happended with the comets appearance. Well condensed 
coma, no hint of color. Straight tail. Slightly brigher W part of the tail in 
PA 355, the E edge of the tail in PA 040 with faint diffuse glow in between. 
Comet and its short tail seen with naked eye, easier than M31. In 7x50B and 
11x80B comet was somewhat brighter than M31 (central parts). Altitude of comet 
9.8 deg in NW over sodium light glow of Skurup town. Comparison star theta And 
(fainter, 4.62VT, A2, alt 7.7) and nu And (brighter, 4.52VT, B3, alt 12.0); 
comet approximately midway in brightness. Weather clear, dark sky, slight breeze, 
dry, -1 C. Lim mag ca 6.5. Site: Lindby observatory, Skurup, Sweden.

   
   
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   2011L4  2013 04 01.83  B  4.5 TK  5.0B    18   2    8   1.3    5 ICQ XX KAR02 
Comment:  Comet visible naked eye.  In the same binocular field of view as M31.  
Tail width spanned from PA 5 to at least 40. Altitude 14º. Observing site:  
Vasteras, Sweden.

 
 
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   2011L4  2013 04 01.82 !S  4.3 TK  5.0B     7        8   1.1  005 ICQ XX WAR01
Comments: Very well condensed coma. Fan shaped tail between PA 005 (main dust tail) 
and 040, diffusing gradually into the background to the E. Comet seen with naked 
eye. Comet altitude 12.1 deg. Comparison star theta And (slightly fainter, 4.62VT, 
A2, alt 11.9) and sigma And (clearly fainter than comet, 4.52VT, A2, alt 10.3). 
Clear, dark, transparent sky, slight breeze, dry, -1c. Lim mag ca 6.5. Site: 
Lindby observatory, Skurup, Sweden.



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   2011L4  2013 03 31.83 !S  4.4 TK  5.0B     7        8   1.2  005 ICQ XX WAR01
   2011L4  2013 03 31.83 !S  4.3 TK     E     1                     ICQ XX WAR01
Comments: Color of comet white, no hint of yellow as seen on and before last 
observation March 26. Coma small and very well condensed. Tail straight and 
slightly longer than seen previously, its W edge sharper than the E. Tail 
formed a faint fan shaped wedge to the E, with the E edge pointing towards 
PA 35. Comet at altitude 10.4 above moderate sodium glow of Skurup town. Comp 
stars sigma And (slightly fainter than comet, 4.52VT, A2, alt 9.8), theta And 
(marginally fainter, 4.62VT, A2, alt 11.4), nu And (brighter, 4.52VT, B3, alt 
16.3). Comet slightly brighter than M31. Comet seen with naked eye, diffuse with 
very faint tail, estimated as slightly brighter than sigma and theta And. Clear, 
dark, transparent sky, calm wind, dry, -2c. Lim mag ca 6.5. Site: Lindby observatory, 
Skurup, Sweden.




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   2011L4  2013 03 28.82  B  3.8 TK  5.0B    18   2    8   1.5   10 ICQ XX KAR02 
Comment:  Visible with naked eye.  Tail gently curving towards left towards PA 50.  
Altitude 11º. Observing site:  Vasteras, Sweden.



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   2011L4  2013 03 26.82 $S  3.9 TK  5.0B     7        8   0.6  018 ICQ XX WAR01
   2011L4  2013 03 26.83 $S  3.9 TK  8.0B    11        8   0.8  018 ICQ XX WAR01
Comments: Comet brightness midway between eps and del And. Very condensed coma 
with bright starlike central core of mag ca 4.8 (its brightness midway between 
eps And 4.45VT and GN And 5.42VT at nearly same altitude) and constituting a large 
part of the comets brightness. Comet slightly yellow, color more intense in central 
core. Coma small but diameter not possible to judge in binoculars. Tail straight, 
somewhat sharper defined on W side, more diffuse on E side. Comet not seen with 
naked eye. Bright sky from nearly full moon in SE, ZLM ca 4.5. Comet alt 8.1 deg 
in NW. Comp stars eps And 4.45VT alt 7.7, del And 3.42VT alt 9.1. Weather clear, 
-1C, transparent sky. Site: Lindby observatory, Skurup, Sweden.




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   2011L4  2013 03 24.81  B  2.8 TK  5.0B    18   1    8   1.1   20 ICQ XX KAR02                                                  
Comment:  Comet easily visible with naked eye.  Differential extinction corrected 
using ICQ winter table.  The width of the tail spanned between about PA 20 - 80.  
92% illuminated gibbous moon disturbed.  Altitude 9º. Observing site:  Vasteras, 
Sweden.

 
 

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    2011L4  2013 03 24.81 $S  3.3 TK  5.0B     7        7   1.0  025 ICQ XX WAR01
  Comments: Magnitude midway between eps (4.45 VT, 10.2 deg) and del (3.42 VT, 
  11.6 deg) And, Comet alt 7.1 deg. 1925 UT. Clear skies, -3C, light wind. Color 
  of comet off-white, slightly yellow. Straight tail more diffuse and spreading 
  out faintly on the E side. Bright sky from gibbous moon in S.  Comet was clearly 
  seen with naked eye. Site: Lindby observatory, Skurup, Sweden.

  
  
 
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   2011L4  2013 03 23.81  B  2.7 TK  5.0B    18   1    8   1.0   25 ICQ XX KAR02
Comment:  Easily visible to naked eye.  The right (N) part of the tail was longer 
and had a sharper border than the opposite side of the tail.  The typical yellow 
color of the comet from last week had disappeared totally and turned into grey-white.  
The central-condensation was very small but not completely stellar.  Thin clouds 
had appeared from NE and covered all the sky except the W horizon up to 15º altitude.  
86% illuminated gibbous moon in the sky.  Altitude 8º. Observing site:  Vasteras, 
Sweden.




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   2011L4  2013 03 23.80 $S  2.8 TK  8.0B    11        7   0.9  025 ICQ XX WAR01
Comments: Magnitude approx midway between eps (4.45 VT, 11.2 deg) and del (3.42 VT, 
12.6 deg) And, slightly closer to del. Comet alt 6.7 deg. 1920 UT. Color of comet 
off-white, slightly yellow. Straight tail more diffuse and spreading out faintly 
on the E side.Clear skies, -3C, light wind. Bright sky from gibbous moon in S. 
Comet seen with naked eye. Site: Lindby observatory, Skurup, Sweden.




2013 Mar. 22.80 KAR02
Comment:  Comet visible with 10x50 binoculars just above some trees.  Tail pointing 
straight up or even weekly towards right (PA 25). Disturbing street-lights.  
Altitude 8º. Observing site:  Vasteras, Sweden.  



2013 Mar. 18.74, 2.2:, -- (T. Karhula, Vasteras, Sweden, naked eye)
Comment:  Found comet Pan-STARRS without optical aid.  Beginning of tail seen stretching 
upwards.  Disturbed by street-lights.



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   2011L4  2013 03 17.80  S  2.0:TK 25.0L 5  50 < 0.5  8   40.0m 28 ICQ XX KARaa
Comment:  Perfect conditions with clear and quite steady air towards the western 
horizon. Fragmentation suspected at 150x with a small dot visible for a couple of 
minutes just off the nucleus PA 50. Observing site: Goteborg, Sweden.



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   2011L4  2013 03 17.77 $C  2.1 TK  6.6R6 a 90   1.5      1.1  054 ICQ XX WAR01I     C  3.0mCKD CAC MIm 0  9*0.3   6.4  3.0s 3.0 
Comments: Sharp W delimitation of tail PA 40. Fainter, fan shaped and diffuse part of tail stretching to E, delimited at PA 135. 
Thus tail opening angle 95 deg. Altitude of comet and comparison star 6.3 deg. Photographic observation i G channel with Eos 400D. 
Site: Lindby observatory, Skurup, Sweden.




2013 Mar. 17.76, 2.1:, -- (T. Karhula, Vasteras, Sweden, naked eye);
Comment:  Found first with 10x50 binoculars and it showed the tail towards PA 35.  
The beginning of the tail could be glimpsed naked eye. Disturbed by street-lights.



2013 Mar. 16.75, 1.5:, -- (T. Karhula, Akesta, Vasteras, Sweden, naked eye);
Comment:   The tail appeared against the bright sky when the solar altitude was -6º.  
Comet visible naked eye at solar altitude -8º before it disappeared behind a distant 
cloud.  No formal magnitude estimate was done but it was to me about of magnitude 
+1.5 or fainter.  Instrument Celestron C-9.25.  Magnifications between 62x - 185x.

 

 2013 Mar. 15.76 KAR02
Comment:  Found comet PanSTARRS first without optical aid then had my first look 
at it with a telescope.  With my 25cm GSO Dobson telescope the comet was very 
pretty, like a great comet but in miniature size!  I was using magnification 
between 52x and 156x. The yellow central condensation (cc) was really tiny, 
almost stellar, 10"-15" in diameter.  Its border was not absolutely sharp but 
possessed a very high surface brightness, almost like Mercury's disc.  The 
entire yellowish tail got room in the field of view with lowest magnification 
and the northern part of the curved tail was clearly longer than the southern 
part.  I only got to see PanSTARRS a short time before it sank behind some 
birches a couple of hundred meters away. 


 
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   2011L4  2013 03 14.78  S  1.0:TK 25.0L 5  92 < 0.5  8   10.0m 45 ICQ XX KARaa 
Comment:  My first view of PanSTARRS. Excellent conditions with clear skies towards 
the western horizon. The nucleus was very tight, with a yellow tint and almost 
planetlike in appearance. Observing site: Goteborg, Sweden.

 

2013 Mar. 14.74, 1.0:, -- (T. Karhula, Vasteras, Sweden, naked eye);
Comment:  Found comet Pan-STARRS without optical aid.  Disturbed by street-lights.

 
 
 
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   2011L4  2013 03 13.73  B  1.0:TK  5.0B     7 < 1    9   15.0m 65 ICQ XX KAR02
Comment:  Found comet Pan-STARRS first with hand-held 20x80 binoculars.  Central 
condensation similar to a fuzzy, yellowish Mercury with a high surface brightness.  
A slightly curved (anti-clockwise), yellow tail visible for about 0º.25 where the 
northern part was longer.  Altitude 14º, solar altitude -6º. Observing site: 
Virsbo, Sweden.
 
 
 
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   2011L4  2013 02 12.68  I  1.5:TK 25.0L    39   0.3   8           ICQ XX WAR01
Comment: Coma round, diffuse, very well condensed, very small, white. Diameter 
compared to Jupiter with a reticle eyepiece. Comet found using GoTo. Bright 
twilight sky. No good magnitude reference star available. Clear weather. Site: 
Lindby observatory, Skurup, Sweden.