Comet C/2019 L3 (ATLAS)

6月10日UT、Haleakalaにある小惑星地球衝突最終警報システム Asteroid Terrestrial-impact Last
Alert System (ATLAS)調査プログラムのコースに0.5-m 反射望遠鏡で得たCCD画像から小惑星状天体
が発見された。
小惑星センターのPCCP webpageに公表後、佐藤英貴氏(東京都文京区, iTelescope 天文台, 0.43-m 
f/6.8 アストログラフ, Mayhill近郊, ニューメキシコ州, 遠隔操作; 6月12.4日UT、60秒露出10枚の
スタックで、強く集光した8"のコマがある)らCCD位置観測者によって彗星状と観測された。

発見位置は次のとおり、

     2019 UT             R.A. (2000) Decl.       Mag.
     June 10.56200   22 50 05.84   +41 52 31.3   18.1
          10.56474   22 50 05.84   +41 52 31.1   18.9
          10.57071   22 50 05.86   +41 52 33.7   18.8
          10.58242   22 50 05.87   +41 52 38.4   18.4
          10.61426   22 50 06.13   +41 52 50.8   18.9

暫定双曲線軌道要素と位置推算表は次のとおり、

Orbital elements:
    C/2019 L3 (ATLAS)
Epoch 2022 Jan. 21.0 TT = JDT 2459600.5
T 2022 Jan. 10.29172 TT                                 MPCLINUX
q   3.5686856            (2000.0)            P               Q
z  -0.0007383      Peri.  171.35819     -0.25920549     -0.66705075
 +/-0.000955       Node   290.88489     +0.83542876     +0.20803031
e   1.0026346      Incl.   48.38154     +0.48463523     -0.71537870
From 161 observations 2019 June 10-30, mean residual 0".5.

    C/2019 L3 (ATLAS)
Epoch 2019 Apr. 27.0 TT = JDT 2458600.5
T 2022 Jan. 10.86903 TT                                 MPCLINUX
q   3.5650311            (2000.0)            P               Q
z  -0.0002190      Peri.  171.46079     -0.26047710     -0.66649536
 +/-0.0009559      Node   290.88877     +0.83577465     +0.20655343
e   1.0007808      Incl.   48.38848     +0.48335537     -0.71632368
From 161 observations 2019 June 10-30, mean residual 0".5.

Ephemeris:
Date    TT    R. A. (2000) Decl.     Delta      r    Elong.  Phase   m1
2019 06 01    22 48 52.0 +40 50 03   8.7652  8.5247    73.0     6.5  18.5
...
2019 06 16    22 50 26.6 +42 27 28   8.5064  8.4292    82.2     6.9  18.4
...
2019 06 24    22 50 27.8 +43 17 42   8.3667  8.3782    87.2     7.0  18.3
...
2019 06 30    22 50 04.7 +43 54 03   8.2621  8.3400    90.9     7.0  18.3
2019 07 01    22 49 58.8 +43 59 58   8.2447  8.3336    91.5     7.0  18.3
2019 07 02    22 49 52.3 +44 05 50   8.2274  8.3272    92.1     7.0  18.3
...
2019 07 08    22 49 00.8 +44 40 05   8.1242  8.2889    95.8     7.0  18.2
...
2019 07 16    22 47 18.9 +45 22 34   7.9894  8.2378   100.6     7.0  18.2
...
2019 07 31    22 42 29.1 +46 29 51   7.7499  8.1419   109.3     6.8  18.1

     This object was reported as asteroidal by the ATLAS team.
Subsequent reports by other observers have shown this to be a comet as 
shown below:

OC   Date     Reporter           Coma    Tail
H06  June 12  H. Sato              8"                         (10 x 60s)
K38  June 14  G. Baj              13"                          
G40  June 16  A. J. Evans         17"
204  June 16  L. Buzzi             9"
B96  June 22  E. Bryssinck        13"                         (11 x 120s)
N55  June 26  D. W. E. Green       6"                         (28 x 40s)
B96  June 26  E. Bryssinck        15"    
850  June 29  D. T. Durig         12"
K88  June 30  K. Sarneczky         6"    25" in P.A. 240

(CBET 4644、MPEC 2019-N11)