| Parameter |
Value |
| Designation |
C/1976 D1 (Bradfield) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1976-02-24T15:11:04.778880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:24Z |
| Obs used |
29 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1976-03-08.0000000 |
| e |
0.99342533 |
| q (au) |
0.847793 |
| a (au) |
128.948233 |
| i (deg) |
46.830935 |
| Ω (om, deg) |
160.792814 |
| ω (w, deg) |
313.000258 |
| M (ma, deg) |
0.008324 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.846 + 2.217\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.846 |
| n |
2.217 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
1.000 |
| 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) |
| 2026-06-01 00:00 |
19:18:47.15 |
+16:36:06.1 |
HIP 94905 |
6.81 |
| 2026-06-01 12:00 |
19:18:45.83 |
+16:36:13.5 |
HIP 94884 |
6.62 |
| 2026-06-02 00:00 |
19:18:44.51 |
+16:36:20.8 |
HIP 94884 |
6.35 |
| 2026-06-02 12:00 |
19:18:43.18 |
+16:36:28.0 |
HIP 94884 |
6.09 |
| 2026-06-03 00:00 |
19:18:41.84 |
+16:36:35.0 |
HIP 94884 |
5.85 |
| 2026-06-03 12:00 |
19:18:40.49 |
+16:36:42.0 |
HIP 94884 |
5.61 |
| 2026-06-04 00:00 |
19:18:39.13 |
+16:36:48.8 |
HIP 94884 |
5.38 |
| 2026-06-04 12:00 |
19:18:37.76 |
+16:36:55.5 |
HIP 94884 |
5.17 |
| 2026-06-05 00:00 |
19:18:36.39 |
+16:37:02.1 |
HIP 94884 |
4.98 |
| 2026-06-05 12:00 |
19:18:35.00 |
+16:37:08.5 |
HIP 94884 |
4.80 |
| 2026-06-06 00:00 |
19:18:33.61 |
+16:37:14.8 |
HIP 94884 |
4.65 |
| 2026-06-06 12:00 |
19:18:32.21 |
+16:37:21.1 |
HIP 94884 |
4.52 |
| 2026-06-07 00:00 |
19:18:30.80 |
+16:37:27.1 |
HIP 94884 |
4.42 |
| 2026-06-07 12:00 |
19:18:29.39 |
+16:37:33.1 |
HIP 94884 |
4.34 |
| 2026-06-08 00:00 |
19:18:27.96 |
+16:37:39.0 |
HIP 94884 |
4.29 |
| 2026-06-08 12:00 |
19:18:26.53 |
+16:37:44.7 |
HIP 94884 |
4.28 |
| 2026-06-09 00:00 |
19:18:25.09 |
+16:37:50.3 |
HIP 94884 |
4.30 |
| 2026-06-09 12:00 |
19:18:23.65 |
+16:37:55.7 |
HIP 94884 |
4.35 |
| 2026-06-10 00:00 |
19:18:22.19 |
+16:38:01.1 |
HIP 94884 |
4.43 |
| 2026-06-10 12:00 |
19:18:20.73 |
+16:38:06.3 |
HIP 94884 |
4.54 |
| 2026-06-11 00:00 |
19:18:19.27 |
+16:38:11.4 |
HIP 94884 |
4.68 |
| 2026-06-11 12:00 |
19:18:17.79 |
+16:38:16.4 |
HIP 94884 |
4.85 |
| 2026-06-12 00:00 |
19:18:16.31 |
+16:38:21.2 |
HIP 94884 |
5.04 |
| 2026-06-12 12:00 |
19:18:14.82 |
+16:38:25.9 |
HIP 94884 |
5.24 |
| 2026-06-13 00:00 |
19:18:13.32 |
+16:38:30.5 |
HIP 94884 |
5.47 |
| 2026-06-13 12:00 |
19:18:11.82 |
+16:38:35.0 |
HIP 94884 |
5.72 |
| 2026-06-14 00:00 |
19:18:10.31 |
+16:38:39.3 |
HIP 94884 |
5.98 |
| 2026-06-14 12:00 |
19:18:08.80 |
+16:38:43.5 |
HIP 94884 |
6.25 |
| 2026-06-15 00:00 |
19:18:07.27 |
+16:38:47.5 |
HIP 94884 |
6.54 |
| 2026-06-15 12:00 |
19:18:05.75 |
+16:38:51.5 |
HIP 94884 |
6.83 |
| 2026-06-16 00:00 |
19:18:04.21 |
+16:38:55.3 |
HIP 94884 |
7.14 |
| 2026-06-16 12:00 |
19:18:02.67 |
+16:38:59.0 |
HIP 94884 |
7.45 |
| 2026-06-17 00:00 |
19:18:01.13 |
+16:39:02.5 |
HIP 94884 |
7.77 |
| 2026-06-17 12:00 |
19:17:59.58 |
+16:39:05.9 |
HIP 94884 |
8.10 |
| 2026-06-18 00:00 |
19:17:58.02 |
+16:39:09.2 |
HIP 94884 |
8.44 |
| 2026-06-18 12:00 |
19:17:56.46 |
+16:39:12.3 |
HIP 94884 |
8.77 |
| 2026-06-19 00:00 |
19:17:54.89 |
+16:39:15.4 |
HIP 94884 |
9.12 |
| 2026-06-19 12:00 |
19:17:53.32 |
+16:39:18.2 |
HIP 94884 |
9.47 |
| 2026-06-20 00:00 |
19:17:51.74 |
+16:39:21.0 |
HIP 94884 |
9.82 |
| 2026-06-20 12:00 |
19:17:50.16 |
+16:39:23.6 |
HIP 94884 |
10.18 |
| 2026-06-21 00:00 |
19:17:48.57 |
+16:39:26.1 |
HIP 94884 |
10.53 |
| 2026-06-21 12:00 |
19:17:46.98 |
+16:39:28.5 |
HIP 94884 |
10.90 |
| 2026-06-22 00:00 |
19:17:45.38 |
+16:39:30.7 |
HIP 94884 |
11.26 |