| Parameter |
Value |
| Designation |
C/1989 A3 (Bradfield) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1988-12-05T05:51:56.764800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:36Z |
| Obs used |
23 |
| NEO |
Yes |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1989-01-25.0000000 |
| e |
0.97809250 |
| q (au) |
0.420517 |
| a (au) |
19.195134 |
| i (deg) |
83.059274 |
| Ω (om, deg) |
28.437814 |
| ω (w, deg) |
194.769984 |
| M (ma, deg) |
0.594842 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.535 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.535 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-1.000 |
| k |
0.987 |
| δ90 |
10.000 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
01:34:11.33 |
+24:55:53.5 |
HIP 7371 |
11.14 |
| 2026-09-20 12:00 |
01:34:08.40 |
+24:55:45.5 |
HIP 7371 |
11.76 |
| 2026-09-21 00:00 |
01:34:05.45 |
+24:55:37.2 |
HIP 7371 |
12.39 |
| 2026-09-21 12:00 |
01:34:02.48 |
+24:55:28.8 |
HIP 7371 |
13.03 |
| 2026-09-22 00:00 |
01:33:59.50 |
+24:55:20.2 |
HIP 7371 |
13.67 |
| 2026-09-22 12:00 |
01:33:56.51 |
+24:55:11.5 |
HIP 7371 |
14.33 |
| 2026-09-23 00:00 |
01:33:53.51 |
+24:55:02.6 |
HIP 7371 |
14.98 |
| 2026-09-23 12:00 |
01:33:50.49 |
+24:54:53.5 |
HIP 7371 |
15.65 |
| 2026-09-24 00:00 |
01:33:47.47 |
+24:54:44.3 |
HIP 7371 |
16.32 |
| 2026-09-24 12:00 |
01:33:44.43 |
+24:54:34.9 |
HIP 7371 |
16.99 |
| 2026-09-25 00:00 |
01:33:41.37 |
+24:54:25.3 |
HIP 7371 |
17.67 |
| 2026-09-25 12:00 |
01:33:38.31 |
+24:54:15.6 |
HIP 7371 |
18.36 |
| 2026-09-26 00:00 |
01:33:35.23 |
+24:54:05.7 |
HIP 7371 |
19.05 |
| 2026-09-26 12:00 |
01:33:32.15 |
+24:53:55.7 |
HIP 7371 |
19.74 |
| 2026-09-27 00:00 |
01:33:29.05 |
+24:53:45.5 |
HIP 7292 |
20.27 |
| 2026-09-27 12:00 |
01:33:25.94 |
+24:53:35.1 |
HIP 7292 |
20.65 |
| 2026-09-28 00:00 |
01:33:22.82 |
+24:53:24.6 |
HIP 7292 |
21.06 |
| 2026-09-28 12:00 |
01:33:19.69 |
+24:53:13.9 |
HIP 7292 |
21.48 |
| 2026-09-29 00:00 |
01:33:16.55 |
+24:53:03.0 |
HIP 7292 |
21.93 |
| 2026-09-29 12:00 |
01:33:13.40 |
+24:52:52.0 |
HIP 7292 |
22.39 |
| 2026-09-30 00:00 |
01:33:10.24 |
+24:52:40.9 |
HIP 7292 |
22.87 |
| 2026-09-30 12:00 |
01:33:07.07 |
+24:52:29.6 |
HIP 7292 |
23.37 |
| 2026-10-01 00:00 |
01:33:03.89 |
+24:52:18.1 |
HIP 7292 |
23.89 |
| 2026-10-01 12:00 |
01:33:00.70 |
+24:52:06.5 |
HIP 7292 |
24.42 |
| 2026-10-02 00:00 |
01:32:57.51 |
+24:51:54.7 |
HIP 7292 |
24.96 |
| 2026-10-02 12:00 |
01:32:54.30 |
+24:51:42.8 |
HIP 7292 |
25.52 |
| 2026-10-03 00:00 |
01:32:51.09 |
+24:51:30.7 |
HIP 7292 |
26.09 |
| 2026-10-03 12:00 |
01:32:47.87 |
+24:51:18.5 |
HIP 7292 |
26.67 |
| 2026-10-04 00:00 |
01:32:44.64 |
+24:51:06.1 |
HIP 7292 |
27.27 |
| 2026-10-04 12:00 |
01:32:41.40 |
+24:50:53.6 |
HIP 7292 |
27.87 |
| 2026-10-05 00:00 |
01:32:38.16 |
+24:50:40.9 |
HIP 7292 |
28.49 |
| 2026-10-05 12:00 |
01:32:34.91 |
+24:50:28.1 |
HIP 7292 |
29.11 |
| 2026-10-06 00:00 |
01:32:31.65 |
+24:50:15.2 |
HIP 7052 |
28.75 |
| 2026-10-06 12:00 |
01:32:28.38 |
+24:50:02.1 |
HIP 7052 |
28.03 |
| 2026-10-07 00:00 |
01:32:25.11 |
+24:49:48.8 |
HIP 7052 |
27.32 |
| 2026-10-07 12:00 |
01:32:21.83 |
+24:49:35.4 |
HIP 7052 |
26.61 |
| 2026-10-08 00:00 |
01:32:18.55 |
+24:49:21.9 |
HIP 7052 |
25.90 |
| 2026-10-08 12:00 |
01:32:15.26 |
+24:49:08.2 |
HIP 7052 |
25.20 |
| 2026-10-09 00:00 |
01:32:11.97 |
+24:48:54.4 |
HIP 7052 |
24.49 |
| 2026-10-09 12:00 |
01:32:08.67 |
+24:48:40.4 |
HIP 7052 |
23.79 |
| 2026-10-10 00:00 |
01:32:05.37 |
+24:48:26.3 |
HIP 7052 |
23.09 |
| 2026-10-10 12:00 |
01:32:02.06 |
+24:48:12.1 |
HIP 7052 |
22.39 |
| 2026-10-11 00:00 |
01:31:58.75 |
+24:47:57.7 |
HIP 7052 |
21.70 |