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Hallo Leute.
Der "alte Hühne" Bill Bradfield hat mal wieder zugeschlagen und einen neuen Kometen entdeckt. Hier die Entdeckungsmeldung und die Ephemeride aus IAUC 8319 & 8320 (CBAT, D. W. Green, 2004). Nur um nix durcheinander zu bringen: mit dieser Bahn ist es *kein* Kreutz-Komet, ist aber trotzdem zwischen 16 und 21. April in SOHO LASCO C3-Bildern zu sehen.
Grüße,
Sebastian
COMET C/2004 F4 (BRADFIELD)
On Mar. 28, A. C. Beresford, Myrtle Bank, South Australia,
reported the visual discovery of a possible new comet close to the
horizon in twilight by William A. Bradfield, during his search for
sungrazing comets, from observations made with a 0.25-m reflector
on Mar. 23.43 and 24.42 UT; further attempts to observe it had
failed until the last few days. The delay in reporting was due to
difficulties in matching the sketch of observations with star
charts. Below are additional observations that have been reported
following requests to several observers.
2004 UT R.A. (2000) Decl. Mag. Observer
Mar. 23.43 1 50.0 - 1 26 8 Bradfield
24.42 1 51.0 - 1 25 "
Apr. 8.4 2 08.5 - 1 36 "
9.368 2 09.1 - 1 24 5 McNaught
11.3461 2 08 32.74 - 0 56 37.8 4 Lovejoy
12.3427 2 07 39.50 - 0 30 59.2 3.3 "
W. A. Bradfield (Yankalilla, S.A.). Original positions given for
equinox 1950.0. Magnitude guessed.
R. H. McNaught and T. M. Smith (Siding Spring Observatory).
Strongly condensed blue coma with diameter about 0'.5; hint of a
tail pointing up from the horizon. Comet low in evening
twilight; 20x120 binoculars. Positional uncertainty stated as
+/- 5'. In-focus magnitude comparable to two nearby stars of mag
5.6. Also observed visually on Apr. 12.358, again almost stellar,
blue, and with a short (perhaps 2'-long?) tail pointing up to the
left at 10 degrees from vertical.
T. Lovejoy (Thornlands, Qld., Australia). Long. = 153.267 deg, Lat.
= -27.55 deg, h = 30 m. On Apr. 11, nineteen co-added CCD images
with Canon 300D camera + 100-mm f/4 camera lens; fairly obvious
tail 0.5 deg long.
The following very preliminary parabolic orbital elements are
from the above observations.
T = 2004 Apr. 17.12 TT Peri. = 332.49
Node = 222.66 2000.0
q = 0.1690 AU Incl. = 63.21
2004 April 12 (8319) Daniel W. E. Green
Ephemeris from orbital elements on IAUC 8319 (H = 8.0, n = 3):
2004 TT R. A. (2000) Decl. Delta r Elong. Phase Mag.
Apr. 5 2 05.53 - 1 44.5 1.288 0.469 18.8 43.4 6.1
7 2 07.42 - 1 40.8 1.227 0.412 17.9 48.3 5.6
9 2 08.68 - 1 29.6 1.159 0.353 16.9 55.4 4.9
11 2 08.75 - 1 03.7 1.085 0.294 15.5 66.0 4.2
13 2 06.59 - 0 07.6 1.005 0.238 13.6 82.6 3.3
15 2 00.31 + 1 51.7 0.923 0.191 10.3 109.6 2.4
17 1 48.03 + 5 43.1 0.856 0.169 5.1 148.4 1.9
19 1 32.28 +11 17.5 0.830 0.186 4.0 157.8 2.1
21 1 18.89 +16 57.2 0.845 0.231 10.3 128.6 2.9
23 1 09.74 +21 44.3 0.882 0.287 15.8 107.3 3.7
25 1 04.02 +25 36.7 0.929 0.346 20.1 92.6 4.4
27 1 00.66 +28 46.2 0.980 0.404 23.4 82.0 5.0
29 0 58.90 +31 23.7 1.031 0.462 26.2 74.1 5.6
May 1 0 58.23 +33 37.4 1.081 0.518 28.5 67.9 6.0
3 0 58.32 +35 33.3 1.130 0.573 30.4 63.0 6.5
5 0 58.93 +37 15.3 1.177 0.626 32.1 58.9 6.8
Der "alte Hühne" Bill Bradfield hat mal wieder zugeschlagen und einen neuen Kometen entdeckt. Hier die Entdeckungsmeldung und die Ephemeride aus IAUC 8319 & 8320 (CBAT, D. W. Green, 2004). Nur um nix durcheinander zu bringen: mit dieser Bahn ist es *kein* Kreutz-Komet, ist aber trotzdem zwischen 16 und 21. April in SOHO LASCO C3-Bildern zu sehen.
Grüße,
Sebastian
COMET C/2004 F4 (BRADFIELD)
On Mar. 28, A. C. Beresford, Myrtle Bank, South Australia,
reported the visual discovery of a possible new comet close to the
horizon in twilight by William A. Bradfield, during his search for
sungrazing comets, from observations made with a 0.25-m reflector
on Mar. 23.43 and 24.42 UT; further attempts to observe it had
failed until the last few days. The delay in reporting was due to
difficulties in matching the sketch of observations with star
charts. Below are additional observations that have been reported
following requests to several observers.
2004 UT R.A. (2000) Decl. Mag. Observer
Mar. 23.43 1 50.0 - 1 26 8 Bradfield
24.42 1 51.0 - 1 25 "
Apr. 8.4 2 08.5 - 1 36 "
9.368 2 09.1 - 1 24 5 McNaught
11.3461 2 08 32.74 - 0 56 37.8 4 Lovejoy
12.3427 2 07 39.50 - 0 30 59.2 3.3 "
W. A. Bradfield (Yankalilla, S.A.). Original positions given for
equinox 1950.0. Magnitude guessed.
R. H. McNaught and T. M. Smith (Siding Spring Observatory).
Strongly condensed blue coma with diameter about 0'.5; hint of a
tail pointing up from the horizon. Comet low in evening
twilight; 20x120 binoculars. Positional uncertainty stated as
+/- 5'. In-focus magnitude comparable to two nearby stars of mag
5.6. Also observed visually on Apr. 12.358, again almost stellar,
blue, and with a short (perhaps 2'-long?) tail pointing up to the
left at 10 degrees from vertical.
T. Lovejoy (Thornlands, Qld., Australia). Long. = 153.267 deg, Lat.
= -27.55 deg, h = 30 m. On Apr. 11, nineteen co-added CCD images
with Canon 300D camera + 100-mm f/4 camera lens; fairly obvious
tail 0.5 deg long.
The following very preliminary parabolic orbital elements are
from the above observations.
T = 2004 Apr. 17.12 TT Peri. = 332.49
Node = 222.66 2000.0
q = 0.1690 AU Incl. = 63.21
2004 April 12 (8319) Daniel W. E. Green
Ephemeris from orbital elements on IAUC 8319 (H = 8.0, n = 3):
2004 TT R. A. (2000) Decl. Delta r Elong. Phase Mag.
Apr. 5 2 05.53 - 1 44.5 1.288 0.469 18.8 43.4 6.1
7 2 07.42 - 1 40.8 1.227 0.412 17.9 48.3 5.6
9 2 08.68 - 1 29.6 1.159 0.353 16.9 55.4 4.9
11 2 08.75 - 1 03.7 1.085 0.294 15.5 66.0 4.2
13 2 06.59 - 0 07.6 1.005 0.238 13.6 82.6 3.3
15 2 00.31 + 1 51.7 0.923 0.191 10.3 109.6 2.4
17 1 48.03 + 5 43.1 0.856 0.169 5.1 148.4 1.9
19 1 32.28 +11 17.5 0.830 0.186 4.0 157.8 2.1
21 1 18.89 +16 57.2 0.845 0.231 10.3 128.6 2.9
23 1 09.74 +21 44.3 0.882 0.287 15.8 107.3 3.7
25 1 04.02 +25 36.7 0.929 0.346 20.1 92.6 4.4
27 1 00.66 +28 46.2 0.980 0.404 23.4 82.0 5.0
29 0 58.90 +31 23.7 1.031 0.462 26.2 74.1 5.6
May 1 0 58.23 +33 37.4 1.081 0.518 28.5 67.9 6.0
3 0 58.32 +35 33.3 1.130 0.573 30.4 63.0 6.5
5 0 58.93 +37 15.3 1.177 0.626 32.1 58.9 6.8
