| 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) |
| 2026-09-20 00:00 |
19:13:41.61 |
+16:14:13.5 |
HIP 94381 |
16.23 |
| 2026-09-20 12:00 |
19:13:41.09 |
+16:13:57.9 |
HIP 94381 |
16.17 |
| 2026-09-21 00:00 |
19:13:40.57 |
+16:13:42.2 |
HIP 94381 |
16.12 |
| 2026-09-21 12:00 |
19:13:40.07 |
+16:13:26.6 |
HIP 94381 |
16.09 |
| 2026-09-22 00:00 |
19:13:39.58 |
+16:13:10.9 |
HIP 94381 |
16.06 |
| 2026-09-22 12:00 |
19:13:39.11 |
+16:12:55.2 |
HIP 94381 |
16.04 |
| 2026-09-23 00:00 |
19:13:38.65 |
+16:12:39.5 |
HIP 94381 |
16.02 |
| 2026-09-23 12:00 |
19:13:38.21 |
+16:12:23.7 |
HIP 94381 |
16.02 |
| 2026-09-24 00:00 |
19:13:37.78 |
+16:12:08.0 |
HIP 94381 |
16.02 |
| 2026-09-24 12:00 |
19:13:37.36 |
+16:11:52.3 |
HIP 94381 |
16.03 |
| 2026-09-25 00:00 |
19:13:36.96 |
+16:11:36.5 |
HIP 94381 |
16.05 |
| 2026-09-25 12:00 |
19:13:36.57 |
+16:11:20.7 |
HIP 94381 |
16.08 |
| 2026-09-26 00:00 |
19:13:36.20 |
+16:11:04.9 |
HIP 94381 |
16.12 |
| 2026-09-26 12:00 |
19:13:35.84 |
+16:10:49.1 |
HIP 94381 |
16.16 |
| 2026-09-27 00:00 |
19:13:35.49 |
+16:10:33.3 |
HIP 94381 |
16.21 |
| 2026-09-27 12:00 |
19:13:35.16 |
+16:10:17.5 |
HIP 94381 |
16.27 |
| 2026-09-28 00:00 |
19:13:34.85 |
+16:10:01.7 |
HIP 94381 |
16.34 |
| 2026-09-28 12:00 |
19:13:34.54 |
+16:09:45.8 |
HIP 94381 |
16.41 |
| 2026-09-29 00:00 |
19:13:34.26 |
+16:09:30.0 |
HIP 94381 |
16.49 |
| 2026-09-29 12:00 |
19:13:33.98 |
+16:09:14.2 |
HIP 94381 |
16.58 |
| 2026-09-30 00:00 |
19:13:33.72 |
+16:08:58.3 |
HIP 94381 |
16.67 |
| 2026-09-30 12:00 |
19:13:33.48 |
+16:08:42.5 |
HIP 94381 |
16.77 |
| 2026-10-01 00:00 |
19:13:33.25 |
+16:08:26.7 |
HIP 94381 |
16.88 |
| 2026-10-01 12:00 |
19:13:33.03 |
+16:08:10.8 |
HIP 94381 |
16.99 |
| 2026-10-02 00:00 |
19:13:32.83 |
+16:07:55.0 |
HIP 94381 |
17.12 |
| 2026-10-02 12:00 |
19:13:32.65 |
+16:07:39.2 |
HIP 94381 |
17.24 |
| 2026-10-03 00:00 |
19:13:32.48 |
+16:07:23.4 |
HIP 94381 |
17.37 |
| 2026-10-03 12:00 |
19:13:32.32 |
+16:07:07.5 |
HIP 94381 |
17.51 |
| 2026-10-04 00:00 |
19:13:32.18 |
+16:06:51.7 |
HIP 94381 |
17.66 |
| 2026-10-04 12:00 |
19:13:32.05 |
+16:06:35.9 |
HIP 94381 |
17.80 |
| 2026-10-05 00:00 |
19:13:31.93 |
+16:06:20.1 |
HIP 94381 |
17.96 |
| 2026-10-05 12:00 |
19:13:31.84 |
+16:06:04.4 |
HIP 94381 |
18.12 |
| 2026-10-06 00:00 |
19:13:31.75 |
+16:05:48.6 |
HIP 94381 |
18.28 |
| 2026-10-06 12:00 |
19:13:31.68 |
+16:05:32.8 |
HIP 94381 |
18.45 |
| 2026-10-07 00:00 |
19:13:31.63 |
+16:05:17.1 |
HIP 94381 |
18.62 |
| 2026-10-07 12:00 |
19:13:31.59 |
+16:05:01.4 |
HIP 94381 |
18.80 |
| 2026-10-08 00:00 |
19:13:31.57 |
+16:04:45.7 |
HIP 94381 |
18.98 |
| 2026-10-08 12:00 |
19:13:31.56 |
+16:04:30.0 |
HIP 94381 |
19.17 |
| 2026-10-09 00:00 |
19:13:31.56 |
+16:04:14.3 |
HIP 94381 |
19.36 |
| 2026-10-09 12:00 |
19:13:31.58 |
+16:03:58.6 |
HIP 94381 |
19.55 |
| 2026-10-10 00:00 |
19:13:31.62 |
+16:03:43.0 |
HIP 94381 |
19.75 |
| 2026-10-10 12:00 |
19:13:31.67 |
+16:03:27.4 |
HIP 94381 |
19.95 |
| 2026-10-11 00:00 |
19:13:31.73 |
+16:03:11.8 |
HIP 94381 |
20.16 |