Comet P/2021 A5 (PANSTARRS) 

R. WerykとR. Wainscoat (ハワイ大学天文学研究所)の通報によると、1月6日UT、Haleakalaに
あるPan-STARRS1 1.8-m Ritchey-Chretien反射望遠鏡で得た45秒3枚のw-バンドCCD画像から
彗星を発見した。この彗星は1".2のシーイングで約2".0 (半値全幅:FWHM)の集光したコマと
p.a. 80°に約4"の尾が見える。

彗星機能の報告は次の通り：

OC   Date        Reporter           Coma    Tail    PA          Exposures
568  2021-01-11  R. Wainscoat       1"       4"     70           
568  2021-01-15  R. Wainscoat       0".35    6"     70           3x60s

発見位置は次のとおり、

     2021 UT             R.A. (2000) Decl.       Mag.
     Jan.  6.29804    0 41 18.22   +25 42 09.1   21.2
           6.30840    0 41 18.85   +25 42 09.4   21.4
           6.31874    0 41 19.48   +25 42 10.1   21.3

MPCの楕円軌道要素、位置推算表は次のとおり、

Orbital elements:
    P/2021 A5 (PANSTARRS)                                                       
Epoch 2020 Nov. 7.0 TT = JDT 2459160.5                                          
T 2020 Nov. 11.25451 TT                                 Rudenko                 
q   2.6205942            (2000.0)            P               Q                  
n   0.18545643     Peri.   61.03946     +0.84502558     -0.50964635             
a   3.0453797      Node   328.76904     +0.31315112     +0.71699188             
e   0.1394852      Incl.   18.18817     +0.43343759     +0.47558726             
P   5.31                                                                        
>From 43 observations 2020 Dec. 16-2021 Jan. 15, mean residual 0".5.             
                                                                                
    P/2021 A5 (PANSTARRS)                                                       
Epoch 2026 Mar. 21.0 TT = JDT 2461120.5                                         
T 2026 Mar. 11.50920 TT                                 Rudenko                 
q   2.6202900            (2000.0)            P               Q                  
n   0.18544600     Peri.   61.67833     +0.83961166     -0.51846348             
a   3.0454939      Node   328.73013     +0.32061405     +0.71378469             
e   0.1396174      Incl.   18.18703     +0.43847336     +0.47085776             
P   5.31                                                                        
>From 43 observations 2020 Dec. 16-2021 Jan. 15, mean residual 0".5.             
                                                                                
    P/2021 A5 (PANSTARRS)                                                       
Epoch 2020 Dec. 17.0 TT = JDT 2459200.5                                         
T 2020 Nov. 11.28412 TT                                 Rudenko                 
q   2.6205967            (2000.0)            P               Q                  
n   0.18545196     Peri.   61.04704     +0.84496047     -0.50975400             
a   3.0454286      Node   328.76876     +0.31324260     +0.71695291             
e   0.1394982      Incl.   18.18813     +0.43349843     +0.47553064             
P   5.31                                                                        
>From 43 observations 2020 Dec. 16-2021 Jan. 15, mean residual 0".5.             
                                                                                
Ephemeris:
Date    TT    R. A. (2000) Decl.     Delta      r    Elong.  Phase   m1
2020 12 16    00 23 36.7 +25 50 53   2.1146  2.6242   110.3    20.6  20.8
...
2020 12 31    00 35 06.7 +25 38 19   2.2963  2.6280    98.5    21.7  21.0
...
2021 01 08    00 43 06.2 +25 44 03   2.3971  2.6305    92.5    21.9  21.1
...
2021 01 14    00 49 49.8 +25 53 34   2.4735  2.6327    88.2    21.9  21.2
2021 01 15    00 51 00.5 +25 55 34   2.4863  2.6331    87.5    21.9  21.2
2021 01 16    00 52 12.1 +25 57 41   2.4990  2.6335    86.8    21.9  21.2
...
2021 01 22    00 59 40.4 +26 12 38   2.5755  2.6359    82.6    21.7  21.3
...
2021 01 30    01 10 24.1 +26 38 03   2.6766  2.6395    77.2    21.3  21.4
...
2021 02 14    01 32 34.2 +27 39 17   2.8615  2.6471    67.6    20.2  21.5

(CBET 4915)、CBET 4915)