GREAT COMETS IN HISTORY
 ---------------------
 John Pazmino
 NYSkiesAstronomy Inc
 nyskies.@nyskies.org
 www.nyskies.org
 1998 March 17 
[This article is reprinted from a webapge once maintained by Alan 
Chamberlin of JPL. He wrote it on 1996 October 2 after the flyover of 
comet Hyakutake in early 1996. This was so spectacular a comet that he 
compiled this table of 'great comets'. He revised it to include comet 
hale-Bopp. Since 1998, thru mid 2011, there were several bright 
comets, like Ikeya-Zhang, but none attained the rank of 'great comet'. 
The issue date is Chamberlin's latest revision. I made some trivial 
adjustments to the original layout.] 
 = = = = =  
  Written:  1996 October 2 
 Modified:  1998 March 17 17:19
       by:  Alan B. Chamberlin
      for:  Solar System Dynamics Group
            Jet Propulsion Laboratory
Great Comets in History
 ---------------------
 Donald K. Yeomans 
 Jet Propulsion Laboratory/California Institute of Technology 
    A relative few comets are so visually impressive as to be termed 
"great comets". Just the right set of circumstances must occur.  Far 
from the sun, the solid portions of comets, which consist mostly of 
water ice and embedded dust particles, are inactive. They are not 
large enough to be seen with the naked eye. However, when near the 
sun, the icy cometary surfaces vaporize and throw off large quantities 
of gas and dust thus forming the enormous atmosphere and tails that 
make comets so visually striking. It is the fluorescing of these 
gases, and particularly the reflection of sunlight from the minute 
dust particles in the comet's atmosphere and tail, that can make these 
objects so visually impressive. However, this activity by itself does 
not insure that a comet will become a great comet. An active comet can 
only become great by making a particularly close approach to the sun 
so that it produces enormous quantities of gas and dust or by making a 
close approach to the Earth so that it's tail can be easily viewed.  
In either case, great comets must be seen in a dark sky.  
    While applying the appellation "great comet" to a particular 
cometary return is a subjective process, the following Table is an 
attempt to list the great naked-eye comets that have been reported.  
With the single exception of periodic comet Halley, all the tabulated 
comets have passed through the inner solar system either for the first 
time or the intervals between their returns are measured in thousands 
or millions of years. 
    The first tabular entry gives the approximate date when the comet 
was first reported as a naked-eye object. The following column gives 
the approximate observational interval (in days) during which the 
comet remained a naked eye object. The next two columns give the date 
and distance in astronomical units when the comet reached its closest 
point to the sun (perihelion). One astronomical unit is the mean 
distance between the sun and Earth. The following columns give the 
date and distance when the comet reached its closest point to the 
Earth (perigee), and the date and apparent magnitude when the comet 
reached its brightest in a dark sky. A diffuse cometary image becomes 
noticeable to the naked eye when it reaches a magnitude of 
approximately 3.4 in a dark sky. Compared to a comet whose magnitude 
is 4, a 3rd magnitude comet would appear 2.5 times brighter and a 
magnitude 2 comet would appear 2.5 x 2.5 = 6.3 times brighter still, 
etc. The brightest star in the sky (Sirius) has an apparent magnitude 
of -1.5.  At its brightest, the planet Jupiter appears at magnitude -
2.7.  
 1st Date    Obs Perihelion        Perigee          Brightness Max. 
 Reported    Int Date     Dist     Date     Dist    Date      Mag  
 YYYY/mmm/DD (d) YYYY/mmm/DD (AU)  YYYY/mmm/DD (AU) YYYY/mmm/DD 
 ----------- --- ----------------- ---------------- ----------- -
 Name, Notes 
 -----------------------------------
 Julian Calendar 
 ---------------
 B.C. dates 
 ----------
  373-372 Winter                                                       
< 1> 
   87/Jul     35   87/Aug/06 0.59    87/Jul/27 0.44   87/Jul/27  2    
1P/Halley 
   12/Aug/25  57   12/Oct/10 0.59    12/Sep/10 0.16   12/Sep/10   1 
1P/Halley 
 A.D. Dates 
 ----------
   66/Jan/30  71   66/Jan/26 0.59    66/Mar/20 0.25   66/Mar/20  1    
1P/Halley 
  141/Mar/26  41  141/Mar/22 0.58   141/Apr/22 0.17   141/Apr/22 -1    
1P/Halley 
  178/Sep     80                                                       
< 2> 
  191/Oct                                                              
< 2> 
  218/May     40  218/May/17 0.58   218/May/30 0.42   218/May/30  0    
1P/Halley 
  240/Nov/10  39  240/Nov/10 0.37   240/Nov/30 1.00   240/Nov/20  1-2  
(240 V1) 
  295/May     30  295/Apr/20 0.58   295/May/12 0.32   295/May/12  0    
1P/Halley 
  374/Mar/03  32  374/Feb/16 0.58   374/Apr/02 0.09   374/Apr/02 -1    
1P/Halley 
  390/Aug/21  26  390/Sep/05 0.92   390/Aug/18 0.10   390/Aug/18 -1    
(390 Q1) < 2> 
  400/Mar/18  30  400/Feb/25 0.21   400/Mar/31 0.08   400/Mar/19  0    
(400 F1) 
  442/Nov/09 100  442/Dec/15 1.53   442/Dec/07 0.58   442/Dec/07  1-2  
(442 V1) 
  451/Jun/09  68  451/Jun/28 0.58   451/Jun/30 0.49   451/Jun/30  0    
1P/Halley 
  565/Jul/22 100  565/Jul/15 0.82   565/Sep/13 0.54   565/Sep/13  0-1  
(565 O1) 
  568/Jul/28 106  568/Aug/27 0.87   568/Sep/25 0.09   568/Sep/25  0    
(568 O1) 
  607/Mar-Apr 30  607/Mar/15 0.58   607/Apr/19 0.09   607/Apr/19 -2    
1P/Halley 
  684/Sep/06  33  684/Oct/02 0.58   684/Sep/07 0.26   684/Sep/07  1-2  
1P/Halley 
  760/May/16  50  760/May/20 0.58   760/Jun/03 0.41   760/Jun/03  0    
1P/Halley 
  770/May/25  62  770/Jun/05 0.58   770/Jul/10 0.30   770/Jul/10  1-2  
(770 K1) 
  837/Mar/21  39  837/Feb/28 0.58   837/Apr/11 0.03   837/Apr/11 -3    
1P/Halley < 3> 
  838/Nov/09  49 
  891/May/12  62                                                  2 
  905/May/18  26  905/Apr/26 0.20   905/May/25 0.21   905/May/23  0-2 
  989/Aug/10  32  989/Sep/05 0.58   989/Aug/20 0.39   989/Aug/20  1-2  
1P/Halley     
 1066/Apr/02  66 1066/Mar/20 0.58  1066/Apr/24 0.10  1066/Apr/24 -1    
1P/Halley 
 1106/Feb/02  40                                                  4            
 1132/Oct/03  24 1132/Aug/30 0.74  1132/Oct/07 0.04  1132/Oct/07 -1    
(1132 T1) 
 1145/Apr/15  65 1145/Apr/18 0.58  1145/May/12 0.27  1145/May/12  0    
1P/Halley 
 1222/Sep/02  36 1222/Sep/28 0.58  1222/Sep/06 0.31  1222/Sep/24  1-2  
1P/Halley < 5> 
 1240/Jan/27  64 1240/Jan/21 0.67  1240/Feb/02 0.36  1240/Feb/02  0    
(1240 B1) 
 1264/Jul/17  85 1264/Jul/20 0.82  1264/Jul/29 0.18  1264/Jul/29  0    
(1264 N1) < 6> 
 1301/Sep/01  61 1301/Oct/25 0.58  1301/Sep/23 0.18  1301/Sep/23  1-2  
1P/Halley 
 1378/Sep/26  15 1378/Nov/10 0.58  1378/Oct/03 0.12  1378/Oct/03  1    
1P/Halley < 7> 
 1402/Feb/08  70 1402/Mar/21 0.38  1402/Feb/19 0.71  1402/Mar/12 -3    
(1402 D1) < 8> 
 1456/May/26  44 1456/Jun/09 0.58  1456/Jun/19 0.45  1456/Jun/19  0    
1P/Halley 
 1468/Sep/18  56 1468/Oct/07 0.85  1468/Oct/02 0.67  1468/Oct/02  1-2  
(1468 S1) 
 1471/Dec/25  59 1472/Mar/01 0.49  1472/Jan/23 0.07  1472/Jan/23 -3    
(1471 Y1) 
 1531/Aug/05  34 1531/Aug/26 0.58  1531/Aug/14 0.44  1531/Aug/27  1    
1P/Halley 
 1532/Sep/02 120 1532/Oct/18 0.52  1532/Sep/21 0.67  1532/Oct/13 -1    
(1532 R1) 
 1533/Jun/27  83 1533/Jun/15 0.25  1533/Aug/02 0.42  1533/Jun/27  0    
(1533 M1) < 9> 
 1556/Feb/27  72 1556/Apr/22 0.49  1556/Mar/13 0.08  1556/Mar/14 -2    
(1556 D1) 
 1577/Nov/01  87 1577/Oct/27 0.18  1577/Nov/10 0.63  1577/Nov/08 -3    
(1577 V1)  
 Gregorian Calendar 
 ------------------
 1618/Nov/16  67 1618/Nov/08 0.40  1618/Dec/06 0.36  1618/Nov/29  0-1  
(1618 W1) 
 1664/Nov/17  75 1664/Dec/04 1.03  1664/Dec/29 0.17  1664/Dec/29 -1    
(1664 W1) 
 1665/Mar/27  24 1665/Apr/24 0.11  1665/Apr/04 0.57  1665/Apr/20 -1    
(1665 F1) <10> 
 1668/Mar/03  27 1668/Feb/28 0.07  1668/Mar/05 0.80  1668/Mar/08  1-2  
(1668 E1) 
 1680/Nov/23  88 1680/Dec/18 0.01  1680/Nov/30 0.42  1680/Dec/29  1-2  
(1680 V1) <11> 
 1682/Aug/15  41 1682/Sep/15 0.58  1682/Aug/31 0.42  1682/Aug/31  0-1  
1P/Halley 
 1686/Aug/12  34 1686/Sep/16 0.34  1686/Aug/16 0.32  1686/Aug/27  1-2  
(1686 R1) 
 1743/Nov/29 110 1744/Mar/01 0.22  1744/Feb/27 0.83  1744/Feb/20 -3    
(1743 X1) <12> 
 1769/Aug/24  94 1769/Oct/08 0.12  1769/Sep/10 0.32  1769/Sep/22  0    
Messier (1769 P1) <13> 
 1807/Sep/09  90 1807/Sep/19 0.65  1807/Sep/27 1.15  1807/Sep/20  1-2  
Great Comet (1807 R1) 
 1811/Apr/11 260 1811/Sep/12 1.04  1811/Oct/16 1.22  1811/Oct/20  0    
Great Comet (1811 F1) 
 1843/Feb/05  48 1843/Feb/27 0.006 1843/Mar/06 0.84  1843/Mar/07 <-3   
Great March Comet (1843 D1) <14> 
 1858/Aug/20  80 1858/Sep/30 0.58  1858/Oct/11 0.54  1858/Oct/07  0-1  
Donati (1858 L1) 
 1861/May/13  90 1861/Jun/12 0.82  1861/Jun/30 0.13  1861/Jun/27  0    
Great Comet (1861 J1) <13> 
 1865/Jan/17  36 1865/Jan/14 0.03  1865/Jan/16 0.94  1865/Jan/24  1    
Great Southern Comet (1865 B1) <15> 
 1874/Jun/10  50 1874/Jul/09 0.68  1874/Jul/23 0.29  1874/Jul/13  0-1  
Coggia (1874 H1) 
 1882/Sep/01 135 1882/Sep/17 0.008 1882/Sep/16 0.99  1882/Sep/08 <-3   
Great September Comet (1882 R1) <16> 
 1901/Apr/12  38 1901/Apr/24 0.24  1901/Apr/30 0.83  1901/May/05  1    
Great Comet (1901 G1)              
 1910/Jan/13  20 1910/Jan/17 0.13  1910/Jan/18 0.86  1910/Jan/30  1-2  
Great January Comet (1910 A1) <17> 
 1910/Apr/10  80 1910/Apr/20 0.59  1910/May/20 0.15  1910/May/20  0-1  
1P/Halley 
 1927/Nov/27  32 1927/Dec/18 0.18  1927/Dec/12 0.75  1927/Dec/08  1    
Skjellerup-Maristany (1927 X1) <18> 
 1965/Oct/03  30 1965/Oct/21 0.008 1965/Oct/17 0.91  1965/Oct/14  2    
Ikeya-Seki (1965 S1) <19> 
 1970/Feb/10  80 1970/Mar/20 0.54  1970/Mar/26 0.69  1970/Mar/20  0-1  
Bennett (1969 Y1) <20> 
 1976/Feb/05  55 1976/Feb/25 0.20  1976/Feb/29 0.79  1976/Mar/01 -1    
West (1975 V1) <21> 
 1996/Mar/15  30 1996/May/01 0.23  1996/Mar/25 0.10  1996/Apr/20  1-2  
Hyakutake (1996 B2) 
 1996/Sep/09 215 1997/Apr/01 0.91  1997/Mar/22 1.32  1997/Mar/26 -0.7  
Hale-Bopp (1995 O1) <22> 
 ---------------------------------------------------------------------
 Notes 
 -----
< I>Reported by the Greek historian Ephorus to have split into two     
pieces. 
< 2>The Chinese reported that the tail spanned more than 70 degrees.
< 3>The closest approach to the Earth that comet Halley has ever made.    
On Apr. 13, the comet's tail was more than 90 degrees in length. 
< 4>This comet passed very close to the sun and is perhaps the    
progenitor of the sungrazing comets of 1882 and 1965 or that of 
    1843.
< 5>Korean observers reported the comet was visible during the 
daylight hours on September 9th (probably during twilight only). 
< 6>On July 26, Chinese observers reported the tail spanning 100     
degrees. 
< 7>Chinese observers reported cloudy weather from October 11 until     
Nov. 9, at which time the comet had passed behind the sun. 
< 8>In mid-March, the comet entered solar conjunction and there were     
reports that it was a daylight object for 8 days. 
< 9>The comet was discovered emerging from solar conjunction.
<10>Last observed on April 20 as it approached solar conjunction.
<11>This was the first comet discovered with the aid of a telescope    
(on Nov. 14). 
<12>Visible in daylight only 12 degrees from the Sun on February 27.
<13>Tail reported as longer than 90 degrees near Earth close approach.
<14>On the date of perihelion, this sungrazing comet was observed in    
daylight nearly one degree from the sun. 
<15>Comet observed in southern hemisphere.
<16>The Great September comet was a brilliant object that was observed    
very close to the sun, and split into at least four separate pieces     
near perihelion. This comet and comet Ikeya-Seki in 1965 are     
believed to be members of the same family of sungrazing comets. 
<17>This comet was easily observed on January 17 only 4.5 degrees from 
the sun. It is often confused with the later apparition of comet    
Halley in mid-1910. 
<18>On December 18, this comet was seen in daylight only 5 degrees 
from the sun. At the end of December, the tail was reported to be     
nearly 40 degrees in length. 
<19>Sungrazing comet Ikeya-Seki split into two or possibly three 
pieces near perihelion. Toward the end of October, the impressive tail 
reached lengths in excess of 45 degrees. 
<20>The tail of comet Bennett reached 10 degrees in mid-March.
<21>Comet West's impressive broad tail reached a length of 30 degrees 
on March 8.  Near perihelion, the comet split into four pieces. 
<22>The observational interval is based on the time during which the 
comet had a total magnitude of 3.4 or brighter.