| Parameter |
Value |
| Designation |
C/1984 A1 (Bradfield 1) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1983-12-27T19:07:03.864000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:31Z |
| Obs used |
33 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1984-02-25.0000000 |
| e |
0.95231517 |
| q (au) |
1.357490 |
| a (au) |
28.467973 |
| i (deg) |
51.800566 |
| Ω (om, deg) |
356.858343 |
| ω (w, deg) |
219.164863 |
| M (ma, deg) |
0.384163 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.897 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.897 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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) |
| 2026-07-29 00:00 |
00:29:11.03 |
+30:46:49.6 |
HIP 2170 |
24.07 |
| 2026-07-29 12:00 |
00:29:09.81 |
+30:46:59.8 |
HIP 2170 |
23.77 |
| 2026-07-30 00:00 |
00:29:08.58 |
+30:47:09.8 |
HIP 2170 |
23.47 |
| 2026-07-30 12:00 |
00:29:07.32 |
+30:47:19.7 |
HIP 2170 |
23.17 |
| 2026-07-31 00:00 |
00:29:06.04 |
+30:47:29.3 |
HIP 2170 |
22.86 |
| 2026-07-31 12:00 |
00:29:04.74 |
+30:47:38.9 |
HIP 2170 |
22.55 |
| 2026-08-01 00:00 |
00:29:03.43 |
+30:47:48.2 |
HIP 2170 |
22.23 |
| 2026-08-01 12:00 |
00:29:02.09 |
+30:47:57.4 |
HIP 2170 |
21.92 |
| 2026-08-02 00:00 |
00:29:00.73 |
+30:48:06.4 |
HIP 2170 |
21.60 |
| 2026-08-02 12:00 |
00:28:59.36 |
+30:48:15.3 |
HIP 2170 |
21.27 |
| 2026-08-03 00:00 |
00:28:57.96 |
+30:48:24.0 |
HIP 2170 |
20.95 |
| 2026-08-03 12:00 |
00:28:56.55 |
+30:48:32.5 |
HIP 2170 |
20.62 |
| 2026-08-04 00:00 |
00:28:55.12 |
+30:48:40.9 |
HIP 2170 |
20.29 |
| 2026-08-04 12:00 |
00:28:53.66 |
+30:48:49.0 |
HIP 2170 |
19.95 |
| 2026-08-05 00:00 |
00:28:52.19 |
+30:48:57.1 |
HIP 2170 |
19.61 |
| 2026-08-05 12:00 |
00:28:50.70 |
+30:49:04.9 |
HIP 2170 |
19.27 |
| 2026-08-06 00:00 |
00:28:49.19 |
+30:49:12.6 |
HIP 2170 |
18.92 |
| 2026-08-06 12:00 |
00:28:47.66 |
+30:49:20.1 |
HIP 2170 |
18.58 |
| 2026-08-07 00:00 |
00:28:46.12 |
+30:49:27.4 |
HIP 2170 |
18.22 |
| 2026-08-07 12:00 |
00:28:44.55 |
+30:49:34.5 |
HIP 2170 |
17.87 |
| 2026-08-08 00:00 |
00:28:42.97 |
+30:49:41.5 |
HIP 2170 |
17.51 |
| 2026-08-08 12:00 |
00:28:41.37 |
+30:49:48.3 |
HIP 2170 |
17.15 |
| 2026-08-09 00:00 |
00:28:39.74 |
+30:49:54.9 |
HIP 2170 |
16.79 |
| 2026-08-09 12:00 |
00:28:38.11 |
+30:50:01.4 |
HIP 2170 |
16.42 |
| 2026-08-10 00:00 |
00:28:36.45 |
+30:50:07.7 |
HIP 2170 |
16.05 |
| 2026-08-10 12:00 |
00:28:34.77 |
+30:50:13.8 |
HIP 2170 |
15.68 |
| 2026-08-11 00:00 |
00:28:33.08 |
+30:50:19.7 |
HIP 2170 |
15.30 |
| 2026-08-11 12:00 |
00:28:31.37 |
+30:50:25.4 |
HIP 2170 |
14.92 |
| 2026-08-12 00:00 |
00:28:29.64 |
+30:50:30.9 |
HIP 2170 |
14.54 |
| 2026-08-12 12:00 |
00:28:27.89 |
+30:50:36.3 |
HIP 2170 |
14.16 |
| 2026-08-13 00:00 |
00:28:26.13 |
+30:50:41.5 |
HIP 2170 |
13.77 |
| 2026-08-13 12:00 |
00:28:24.35 |
+30:50:46.5 |
HIP 2170 |
13.38 |
| 2026-08-14 00:00 |
00:28:22.55 |
+30:50:51.3 |
HIP 2170 |
12.98 |
| 2026-08-14 12:00 |
00:28:20.74 |
+30:50:56.0 |
HIP 2170 |
12.58 |
| 2026-08-15 00:00 |
00:28:18.91 |
+30:51:00.5 |
HIP 2170 |
12.18 |
| 2026-08-15 12:00 |
00:28:17.06 |
+30:51:04.7 |
HIP 2170 |
11.78 |
| 2026-08-16 00:00 |
00:28:15.19 |
+30:51:08.8 |
HIP 2170 |
11.38 |
| 2026-08-16 12:00 |
00:28:13.31 |
+30:51:12.7 |
HIP 2170 |
10.97 |
| 2026-08-17 00:00 |
00:28:11.41 |
+30:51:16.5 |
HIP 2170 |
10.56 |
| 2026-08-17 12:00 |
00:28:09.50 |
+30:51:20.0 |
HIP 2170 |
10.14 |
| 2026-08-18 00:00 |
00:28:07.57 |
+30:51:23.4 |
HIP 2170 |
9.73 |
| 2026-08-18 12:00 |
00:28:05.62 |
+30:51:26.5 |
HIP 2170 |
9.31 |
| 2026-08-19 00:00 |
00:28:03.66 |
+30:51:29.5 |
HIP 2170 |
8.89 |