Post-Perihelion Observations of Comet Hyakutake with ROSAT
Comet Hyakutake was observed with ROSAT around the
following dates:
1996-Jun-22
1996-Jul-15
1996-Aug-12
1996-Sep-02
ROSAT observations of comet Hyakutake in June 1996:
================================================
ROR date start dur R.A. Dec.
yymmdd sec sec deg deg
------------------------------------------------
180102 960622 8974 966 67.447 -48.919
180103 960622 37282 1308 67.897 -49.287
180104 960622 66227 1028 68.341 -49.651
180105 960622 77678 1867 68.524 -49.801
180106 960623 36856 1329 69.235 -50.384
180107 960623 42646 1269 69.324 -50.457
180108 960623 65746 1089 69.685 -50.752
================================================
Result (cf. IAUC 6433):
"... The (X-ray) image, corrected for the proper motion of the comet,
shows an extended source with a radial extent of at least 8' (400 000 km).
The peak surface brightness was at 0.002 count sE-1 arcminE-2,
approximately a factor of 5 lower than during the previous ROSAT
observations in March (IAUC 6373). The reacquisition of C/1996 B2
after perihelion confirms the continuous behavior of x-ray emission
in the comet. ..."
ROSAT observations of comet Hyakutake in July 1996:
================================================
ROR date start dur R.A. Dec.
yymmdd sec sec deg deg
------------------------------------------------
180110 960715 23820 1084 109.691 -67.274
180111 960715 29505 1130 109.842 -67.300
180112 960715 35205 1189 109.994 -67.327
180113 960715 40980 1114 110.145 -67.354
180114 960715 80820 1405 111.210 -67.541
180115 960716 240 1282 111.363 -67.568
180116 960716 6045 1251 111.515 -67.592
180117 960716 11850 1146 111.668 -67.617
180118 960716 17625 1101 111.820 -67.641
180119 960716 23355 1101 111.980 -67.667
180120 960716 29040 1147 112.124 -67.690
180121 960716 34755 1132 112.285 -67.716
================================================
ROSAT observations of comet Hyakutake in August 1996:
In order to investigate the extent of the X-ray emission region
of comet Hyakutake, ROSAT for the first time has performed a raster
observation of a moving target.
In the table below, the coordinates of the comet's nucleus during an
individual observation are specified by R.A. and Dec., and the offset
of the center of the HRI FOV is specified by XBOR and YBOR.
========================================================================
ROR date start dur R.A. Dec. XBOR YBOR
yymmdd sec sec deg deg deg deg
------------------------------------------------------------------------
180126 960812 13868 1417 166.938 -69.500 0.100 0.100
180129 960813 24625 1445 168.628 -69.381 -0.100 -0.100
180130 960813 30415 1250 168.717 -69.374 0.100 0.100
180131 960814 7015 1595 169.774 -69.295 -0.100 0.100
180132 960814 24145 1430 170.071 -69.272 0.100 -0.100
180133 960814 29845 1325 170.157 -69.265 -0.100 -0.100
180133 960814 32085 630 170.157 -69.265 -0.100 -0.100
180134 960814 36086 769 170.265 -69.257 0.100 0.100
180134 960814 37890 956 170.265 -69.257 0.100 0.100
180135 960815 6460 1685 171.196 -69.183 -0.100 0.100
180136 960815 23672 1393 171.465 -69.161 0.100 -0.100
180137 960816 5950 1715 172.579 -69.069 -0.100 -0.100
180138 960817 5500 1685 173.921 -68.954 0.100 0.100
180139 960817 16931 1609 174.094 -68.938 -0.100 0.100
180140 960817 74275 650 175.000 -68.858 0.100 -0.100
180141 960817 85695 1605 175.143 -68.844 -0.100 -0.100
180142 960818 85214 1651 176.414 -68.727 0.100 0.100
========================================================================
ROSAT observations of comet Hyakutake in September 1996:
========================================================================
ROR date start dur R.A. Dec. XBOR YBOR
yymmdd sec sec deg deg deg deg
------------------------------------------------------------------------
180146 960902 40695 758 192.143 -67.034
180146 960902 63675 698 192.143 -67.034
180146 960902 72703 1152 192.143 -67.034
180146 960902 78373 1212 192.143 -67.034
180147 960903 51600 818 193.100 -66.923
180147 960903 66507 1213 193.100 -66.923
180147 960903 72237 1243 193.100 -66.923
180147 960903 77967 1243 193.100 -66.923
180148 960904 45480 827 193.947 -66.825
180148 960904 51135 825 193.947 -66.825
180148 960904 71766 1324 193.947 -66.825
180148 960904 77496 1314 193.947 -66.825
180149 960905 33525 806 194.753 -66.732
180149 960905 39270 810 194.753 -66.732
180149 960905 45000 810 194.753 -66.732
180149 960905 56415 849 194.753 -66.732
180149 960905 65620 1295 194.753 -66.732
180149 960905 71281 1349 194.753 -66.732
180149 960905 77086 1214 194.753 -66.732
========================================================================
jer
/ 1996-Sep-02