| 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) |
| 2026-03-26 00:00 |
01:29:16.71 |
+23:40:41.6 |
HIP 6975 |
7.36 |
| 2026-03-26 12:00 |
01:29:19.64 |
+23:40:54.3 |
HIP 6975 |
6.67 |
| 2026-03-27 00:00 |
01:29:22.57 |
+23:41:07.2 |
HIP 6975 |
5.99 |
| 2026-03-27 12:00 |
01:29:25.52 |
+23:41:20.2 |
HIP 6975 |
5.31 |
| 2026-03-28 00:00 |
01:29:28.47 |
+23:41:33.3 |
HIP 6975 |
4.63 |
| 2026-03-28 12:00 |
01:29:31.42 |
+23:41:46.6 |
HIP 6975 |
3.97 |
| 2026-03-29 00:00 |
01:29:34.39 |
+23:42:00.0 |
HIP 6975 |
3.32 |
| 2026-03-29 12:00 |
01:29:37.36 |
+23:42:13.5 |
HIP 6975 |
2.71 |
| 2026-03-30 00:00 |
01:29:40.34 |
+23:42:27.1 |
HIP 6975 |
2.17 |
| 2026-03-30 12:00 |
01:29:43.32 |
+23:42:40.9 |
HIP 6975 |
1.75 |
| 2026-03-31 00:00 |
01:29:46.31 |
+23:42:54.8 |
HIP 6975 |
1.58 |
| 2026-03-31 12:00 |
01:29:49.31 |
+23:43:08.8 |
HIP 6975 |
1.72 |
| 2026-04-01 00:00 |
01:29:52.32 |
+23:43:22.9 |
HIP 6975 |
2.12 |
| 2026-04-01 12:00 |
01:29:55.33 |
+23:43:37.2 |
HIP 6975 |
2.66 |
| 2026-04-02 00:00 |
01:29:58.34 |
+23:43:51.6 |
HIP 6975 |
3.28 |
| 2026-04-02 12:00 |
01:30:01.36 |
+23:44:06.1 |
HIP 6975 |
3.94 |
| 2026-04-03 00:00 |
01:30:04.39 |
+23:44:20.7 |
HIP 6975 |
4.63 |
| 2026-04-03 12:00 |
01:30:07.42 |
+23:44:35.4 |
HIP 6975 |
5.32 |
| 2026-04-04 00:00 |
01:30:10.46 |
+23:44:50.3 |
HIP 6975 |
6.04 |
| 2026-04-04 12:00 |
01:30:13.50 |
+23:45:05.2 |
HIP 6975 |
6.75 |
| 2026-04-05 00:00 |
01:30:16.54 |
+23:45:20.3 |
HIP 6975 |
7.48 |
| 2026-04-05 12:00 |
01:30:19.59 |
+23:45:35.5 |
HIP 6975 |
8.21 |
| 2026-04-06 00:00 |
01:30:22.65 |
+23:45:50.8 |
HIP 6975 |
8.94 |
| 2026-04-06 12:00 |
01:30:25.71 |
+23:46:06.3 |
HIP 6975 |
9.67 |
| 2026-04-07 00:00 |
01:30:28.77 |
+23:46:21.8 |
HIP 6975 |
10.41 |
| 2026-04-07 12:00 |
01:30:31.83 |
+23:46:37.4 |
HIP 6975 |
11.16 |
| 2026-04-08 00:00 |
01:30:34.90 |
+23:46:53.2 |
HIP 6975 |
11.90 |
| 2026-04-08 12:00 |
01:30:37.97 |
+23:47:09.0 |
HIP 6975 |
12.65 |
| 2026-04-09 00:00 |
01:30:41.05 |
+23:47:25.0 |
HIP 6975 |
13.39 |
| 2026-04-09 12:00 |
01:30:44.12 |
+23:47:41.1 |
HIP 6975 |
14.14 |
| 2026-04-10 00:00 |
01:30:47.20 |
+23:47:57.3 |
HIP 6975 |
14.89 |
| 2026-04-10 12:00 |
01:30:50.28 |
+23:48:13.6 |
HIP 6975 |
15.65 |
| 2026-04-11 00:00 |
01:30:53.37 |
+23:48:30.0 |
HIP 6975 |
16.40 |
| 2026-04-11 12:00 |
01:30:56.45 |
+23:48:46.4 |
HIP 6975 |
17.16 |
| 2026-04-12 00:00 |
01:30:59.54 |
+23:49:03.0 |
HIP 6975 |
17.91 |
| 2026-04-12 12:00 |
01:31:02.63 |
+23:49:19.7 |
HIP 6975 |
18.67 |
| 2026-04-13 00:00 |
01:31:05.72 |
+23:49:36.5 |
HIP 6975 |
19.43 |
| 2026-04-13 12:00 |
01:31:08.81 |
+23:49:53.4 |
HIP 6975 |
20.19 |
| 2026-04-14 00:00 |
01:31:11.90 |
+23:50:10.4 |
HIP 6975 |
20.95 |
| 2026-04-14 12:00 |
01:31:14.99 |
+23:50:27.5 |
HIP 6975 |
21.71 |
| 2026-04-15 00:00 |
01:31:18.09 |
+23:50:44.6 |
HIP 6975 |
22.47 |
| 2026-04-15 12:00 |
01:31:21.18 |
+23:51:01.9 |
HIP 6975 |
23.24 |
| 2026-04-16 00:00 |
01:31:24.27 |
+23:51:19.3 |
HIP 7217 |
23.42 |