[Iaude] CBET 4663: COMET P/2008 Y1

quai at eps.harvard.edu quai at eps.harvard.edu
Mon Sep 9 16:24:46 EDT 2019


                                                  Electronic Telegram No. 4663
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau at eps.harvard.edu (alternate cbat at iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET P/2019 R1 = P/2008 Y1 (BOATTINI)
     G. Borisov reported his apparent independent discovery of another comet
on images taken on Sept. 2.0 UT with a 0.65-m f/1.5 astrograph at the MARGO
observatory near Nauchnij, Crimea (discovery observations tabulated below);
the object shows a diffuse, moderately diffuse coma of diameter about 15"
with a tail 30" long in p.a. 280 deg; the total red magnitude of the comet
was 16.0 as measured in a circular aperture of size 0'.5.

     2019 UT             R.A. (2000) Decl.       Mag.   Observer
     Sept. 2.00918    6 49 02.98   +25 42 48.1   15.8   Borisov
           2.01863    6 49 05.36   +25 42 41.3   15.8     "
           2.02941    6 49 07.95   +25 42 34.0   15.7     "

After the object was posted on the Minor Planet Center's PCCP webpage, other
CCD astrometrists have also commented on the cometary appearance.  H. Sato,
Tokyo, Japan, writes that stacked 60-s exposures taken on Sept. 3.4-3.5 UT
with a 0.43-m f/6.8 astrograph near Mayhill, NM, USA, show a strongly
condensed coma 18"-20" in diameter and a 30" tail toward p.a. 280 degrees;
the magnitude was 16.7 as measured within a circular aperture of radius 10".
Sixteen stacked 40-s unfiltered exposures taken by T. Chen with a 0.3-m f/7.2
reflector at Ngari, Tibet, China, in the course of the BIST survey (cf. CBET
4629) around Sept. 4.91 (and measured by D. W. E. Green) show a poorly
condensed, very faint coma of size perhaps 6" with a possible very faint
extension toward p.a. about 267 degrees.  Thirteen stacked BIST exposures
taken on Sept. 5.9 show a moderately condensed coma of size about 8" (and
total magnitude 17.6 in a 12" circular aperture) slightly elongated along
p.a. 306/113 degrees, with a possible very faint, diffuse tail toward p.a.
about 278 degrees.  Fifteen stacked BIST exposures taken on Sept. 6.9 show
a moderately condensed coma of size about 8" with a faint, diffuse tail
toward p.a. about 272 degrees; the total unfiltered magnitude was 17.3-17.4
in a 14"-diameter circular aperture.  Twenty-nine stacked BIST exposures
taken on Sept. 7.9 show an oddly-structured coma of size about 12" (in
seeing about 2".8) with a faint, broad, diffuse tail toward p.a. about
275-285 degrees; the total magnitude was 16.6-16.9 in a 14"-diameter
circular aperture.
     G. V. Williams, Minor Planet Center, has identified this comet as a
recovery of comet P/2008 Y1 (cf. IAUCs 9007, 9016); Williams notes that the
indicated correction to the prediction by B. G. Marsden on MPC 102107 is
Delta(T) = -4.38 days.  The indicated correction to the prediction by S.
Nakano in the ICQ's 2019 Comet Handbook (and NK 3205) is Delta(T) = -4.47
days, adding that the residuals for the recovery observations were +2.59
degrees in R.A. and -0.85 degree in Decl. from his prediction..  Nakano
provides the following linked orbital elements from 244 observations
spanning 2008-2019 (mean residual 0".63), adding that he has been unable to
find additional archival observations of this object in the past.

                    Epoch = 2009 Feb. 18.0 TT
     T = 2009 Feb. 25.10199 TT        Peri. = 162.37013
     e = 0.7346886                    Node  = 259.71082 2000.0
     q = 1.2719224 AU                 Incl. =   8.80518
       a =  4.7940727 AU   n = 0.09389601   P =  10.50 years

                    Epoch = 2019 Aug. 25.0 TT
     T = 2019 Sept. 6.18206 TT        Peri. = 162.80770
     e = 0.7360016                    Node  = 259.34027 2000.0
     q = 1.2678393 AU                 Incl. =   8.91710
       a =  4.8024514 AU   n = 0.09365039   P =  10.52 years

                    Epoch = 2030 Feb. 28.0 TT
     T = 2030 Mar. 14.74655 TT        Peri. = 162.82440
     e = 0.7360060                    Node  = 259.19132 2000.0
     q = 1.2683954 AU                 Incl. =   8.92416
       a =  4.8046382 AU   n = 0.09358646   P =  10.53 years

The following ephemeris by the undersigned from the above orbital elements
uses power-law photometric parameters H = 15.0 and 2.5n = 10.0.

Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase  Mag.
2019 08 25    06 15.83   +27 00.0    1.488    1.278    57.8    42.0  16.9
2019 08 30    06 36.73   +26 15.2    1.477    1.271    57.9    42.3  16.9
2019 09 04    06 57.06   +25 19.4    1.469    1.268    58.1    42.5  16.9
2019 09 09    07 16.72   +24 13.8    1.463    1.268    58.4    42.5  16.9
2019 09 14    07 35.63   +22 59.8    1.459    1.272    58.7    42.5  16.9
2019 09 19    07 53.73   +21 38.7    1.457    1.279    59.2    42.5  16.9
2019 09 24    08 10.99   +20 11.9    1.457    1.289    59.9    42.3  16.9
2019 09 29    08 27.39   +18 40.8    1.457    1.302    60.7    42.1  17.0
2019 10 04    08 42.91   +17 06.6    1.457    1.319    61.6    41.9  17.0
2019 10 09    08 57.58   +15 30.5    1.458    1.338    62.7    41.6  17.1
2019 10 14    09 11.40   +13 53.5    1.459    1.360    64.0    41.3  17.2
2019 10 19    09 24.39   +12 16.4    1.459    1.384    65.5    40.9  17.2
2019 10 24    09 36.58   +10 40.1    1.459    1.411    67.1    40.5  17.3
2019 10 29    09 47.98   +09 05.1    1.458    1.439    68.9    40.1  17.4
2019 11 03    09 58.58   +07 32.2    1.456    1.470    71.0    39.6  17.5
2019 11 08    10 08.41   +06 01.7    1.452    1.502    73.1    39.1  17.6
2019 11 13    10 17.47   +04 34.1    1.448    1.536    75.5    38.6  17.7
2019 11 18    10 25.77   +03 09.7    1.442    1.571    78.1    38.0  17.8
2019 11 23    10 33.28   +01 48.9    1.434    1.608    80.9    37.3  17.8
2019 11 28    10 40.01   +00 32.0    1.425    1.645    83.9    36.6  17.9
2019 12 03    10 45.92   -00 40.7    1.415    1.683    87.1    35.8  18.0
2019 12 08    10 51.00   -01 48.9    1.404    1.722    90.5    34.9  18.1
2019 12 13    10 55.24   -02 52.3    1.392    1.762    94.1    33.9  18.2
2019 12 18    10 58.60   -03 50.6    1.380    1.803    98.0    32.7  18.3
2019 12 23    11 01.07   -04 43.4    1.367    1.844   102.1    31.4  18.3


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2019 CBAT
2019 September 9                 (CBET 4663)              Daniel W. E. Green



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