| 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) |
| 2026-05-12 00:00 |
01:33:59.69 |
+24:07:58.0 |
HIP 7244 |
13.24 |
| 2026-05-12 12:00 |
01:34:02.48 |
+24:08:18.5 |
HIP 7244 |
13.93 |
| 2026-05-13 00:00 |
01:34:05.26 |
+24:08:39.0 |
HIP 7244 |
14.62 |
| 2026-05-13 12:00 |
01:34:08.03 |
+24:08:59.6 |
HIP 7244 |
15.32 |
| 2026-05-14 00:00 |
01:34:10.79 |
+24:09:20.1 |
HIP 7244 |
16.01 |
| 2026-05-14 12:00 |
01:34:13.54 |
+24:09:40.7 |
HIP 7244 |
16.71 |
| 2026-05-15 00:00 |
01:34:16.27 |
+24:10:01.3 |
HIP 7244 |
17.40 |
| 2026-05-15 12:00 |
01:34:19.00 |
+24:10:22.0 |
HIP 7244 |
18.10 |
| 2026-05-16 00:00 |
01:34:21.71 |
+24:10:42.6 |
HIP 7244 |
18.79 |
| 2026-05-16 12:00 |
01:34:24.41 |
+24:11:03.3 |
HIP 7244 |
19.48 |
| 2026-05-17 00:00 |
01:34:27.09 |
+24:11:23.9 |
HIP 7244 |
20.17 |
| 2026-05-17 12:00 |
01:34:29.77 |
+24:11:44.6 |
HIP 7244 |
20.86 |
| 2026-05-18 00:00 |
01:34:32.43 |
+24:12:05.3 |
HIP 7244 |
21.55 |
| 2026-05-18 12:00 |
01:34:35.08 |
+24:12:26.1 |
HIP 7244 |
22.24 |
| 2026-05-19 00:00 |
01:34:37.71 |
+24:12:46.8 |
HIP 7244 |
22.92 |
| 2026-05-19 12:00 |
01:34:40.33 |
+24:13:07.5 |
HIP 7244 |
23.61 |
| 2026-05-20 00:00 |
01:34:42.94 |
+24:13:28.3 |
HIP 7487 |
23.20 |
| 2026-05-20 12:00 |
01:34:45.53 |
+24:13:49.0 |
HIP 7487 |
22.61 |
| 2026-05-21 00:00 |
01:34:48.11 |
+24:14:09.8 |
HIP 7487 |
22.04 |
| 2026-05-21 12:00 |
01:34:50.68 |
+24:14:30.5 |
HIP 7487 |
21.48 |
| 2026-05-22 00:00 |
01:34:53.23 |
+24:14:51.3 |
HIP 7487 |
20.92 |
| 2026-05-22 12:00 |
01:34:55.76 |
+24:15:12.0 |
HIP 7487 |
20.38 |
| 2026-05-23 00:00 |
01:34:58.28 |
+24:15:32.8 |
HIP 7487 |
19.85 |
| 2026-05-23 12:00 |
01:35:00.79 |
+24:15:53.6 |
HIP 7487 |
19.33 |
| 2026-05-24 00:00 |
01:35:03.28 |
+24:16:14.3 |
HIP 7487 |
18.83 |
| 2026-05-24 12:00 |
01:35:05.76 |
+24:16:35.1 |
HIP 7487 |
18.34 |
| 2026-05-25 00:00 |
01:35:08.22 |
+24:16:55.8 |
HIP 7487 |
17.86 |
| 2026-05-25 12:00 |
01:35:10.67 |
+24:17:16.5 |
HIP 7487 |
17.40 |
| 2026-05-26 00:00 |
01:35:13.10 |
+24:17:37.3 |
HIP 7487 |
16.95 |
| 2026-05-26 12:00 |
01:35:15.51 |
+24:17:58.0 |
HIP 7487 |
16.52 |
| 2026-05-27 00:00 |
01:35:17.91 |
+24:18:18.7 |
HIP 7487 |
16.11 |
| 2026-05-27 12:00 |
01:35:20.29 |
+24:18:39.4 |
HIP 7487 |
15.72 |
| 2026-05-28 00:00 |
01:35:22.66 |
+24:19:00.1 |
HIP 7487 |
15.35 |
| 2026-05-28 12:00 |
01:35:25.01 |
+24:19:20.8 |
HIP 7487 |
15.00 |
| 2026-05-29 00:00 |
01:35:27.34 |
+24:19:41.4 |
HIP 7487 |
14.67 |
| 2026-05-29 12:00 |
01:35:29.65 |
+24:20:02.1 |
HIP 7487 |
14.37 |
| 2026-05-30 00:00 |
01:35:31.95 |
+24:20:22.7 |
HIP 7487 |
14.09 |
| 2026-05-30 12:00 |
01:35:34.24 |
+24:20:43.3 |
HIP 7487 |
13.84 |
| 2026-05-31 00:00 |
01:35:36.50 |
+24:21:03.9 |
HIP 7487 |
13.61 |
| 2026-05-31 12:00 |
01:35:38.75 |
+24:21:24.5 |
HIP 7487 |
13.41 |
| 2026-06-01 00:00 |
01:35:40.98 |
+24:21:45.0 |
HIP 7487 |
13.24 |
| 2026-06-01 12:00 |
01:35:43.19 |
+24:22:05.5 |
HIP 7487 |
13.10 |
| 2026-06-02 00:00 |
01:35:45.39 |
+24:22:26.0 |
HIP 7487 |
12.99 |