| 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) |
| 2026-03-26 00:00 |
19:19:52.61 |
+16:07:11.8 |
HIP 94991 |
22.76 |
| 2026-03-26 12:00 |
19:19:53.05 |
+16:07:27.3 |
HIP 94991 |
22.51 |
| 2026-03-27 00:00 |
19:19:53.48 |
+16:07:42.9 |
HIP 94991 |
22.26 |
| 2026-03-27 12:00 |
19:19:53.90 |
+16:07:58.4 |
HIP 94991 |
22.01 |
| 2026-03-28 00:00 |
19:19:54.30 |
+16:08:13.9 |
HIP 94991 |
21.76 |
| 2026-03-28 12:00 |
19:19:54.69 |
+16:08:29.4 |
HIP 94991 |
21.52 |
| 2026-03-29 00:00 |
19:19:55.06 |
+16:08:45.0 |
HIP 94991 |
21.27 |
| 2026-03-29 12:00 |
19:19:55.42 |
+16:09:00.5 |
HIP 94991 |
21.02 |
| 2026-03-30 00:00 |
19:19:55.77 |
+16:09:16.0 |
HIP 94991 |
20.77 |
| 2026-03-30 12:00 |
19:19:56.10 |
+16:09:31.6 |
HIP 94991 |
20.52 |
| 2026-03-31 00:00 |
19:19:56.41 |
+16:09:47.1 |
HIP 94991 |
20.28 |
| 2026-03-31 12:00 |
19:19:56.71 |
+16:10:02.7 |
HIP 94991 |
20.03 |
| 2026-04-01 00:00 |
19:19:57.00 |
+16:10:18.2 |
HIP 94991 |
19.78 |
| 2026-04-01 12:00 |
19:19:57.27 |
+16:10:33.7 |
HIP 94991 |
19.53 |
| 2026-04-02 00:00 |
19:19:57.53 |
+16:10:49.3 |
HIP 94991 |
19.28 |
| 2026-04-02 12:00 |
19:19:57.77 |
+16:11:04.8 |
HIP 94991 |
19.04 |
| 2026-04-03 00:00 |
19:19:58.00 |
+16:11:20.3 |
HIP 94991 |
18.79 |
| 2026-04-03 12:00 |
19:19:58.21 |
+16:11:35.8 |
HIP 94991 |
18.54 |
| 2026-04-04 00:00 |
19:19:58.41 |
+16:11:51.3 |
HIP 94991 |
18.30 |
| 2026-04-04 12:00 |
19:19:58.59 |
+16:12:06.8 |
HIP 94991 |
18.05 |
| 2026-04-05 00:00 |
19:19:58.76 |
+16:12:22.3 |
HIP 94991 |
17.80 |
| 2026-04-05 12:00 |
19:19:58.92 |
+16:12:37.8 |
HIP 94991 |
17.55 |
| 2026-04-06 00:00 |
19:19:59.06 |
+16:12:53.2 |
HIP 94991 |
17.31 |
| 2026-04-06 12:00 |
19:19:59.19 |
+16:13:08.7 |
HIP 94991 |
17.06 |
| 2026-04-07 00:00 |
19:19:59.30 |
+16:13:24.1 |
HIP 94991 |
16.81 |
| 2026-04-07 12:00 |
19:19:59.39 |
+16:13:39.5 |
HIP 94991 |
16.56 |
| 2026-04-08 00:00 |
19:19:59.47 |
+16:13:54.9 |
HIP 94991 |
16.32 |
| 2026-04-08 12:00 |
19:19:59.54 |
+16:14:10.3 |
HIP 94991 |
16.07 |
| 2026-04-09 00:00 |
19:19:59.59 |
+16:14:25.7 |
HIP 94991 |
15.82 |
| 2026-04-09 12:00 |
19:19:59.63 |
+16:14:41.0 |
HIP 94991 |
15.57 |
| 2026-04-10 00:00 |
19:19:59.65 |
+16:14:56.3 |
HIP 94991 |
15.32 |
| 2026-04-10 12:00 |
19:19:59.66 |
+16:15:11.6 |
HIP 94991 |
15.08 |
| 2026-04-11 00:00 |
19:19:59.66 |
+16:15:26.9 |
HIP 94991 |
14.83 |
| 2026-04-11 12:00 |
19:19:59.63 |
+16:15:42.1 |
HIP 94991 |
14.58 |
| 2026-04-12 00:00 |
19:19:59.60 |
+16:15:57.4 |
HIP 94991 |
14.33 |
| 2026-04-12 12:00 |
19:19:59.55 |
+16:16:12.6 |
HIP 94991 |
14.08 |
| 2026-04-13 00:00 |
19:19:59.48 |
+16:16:27.7 |
HIP 94991 |
13.83 |
| 2026-04-13 12:00 |
19:19:59.40 |
+16:16:42.9 |
HIP 94991 |
13.58 |
| 2026-04-14 00:00 |
19:19:59.31 |
+16:16:58.0 |
HIP 94991 |
13.33 |
| 2026-04-14 12:00 |
19:19:59.20 |
+16:17:13.0 |
HIP 94991 |
13.08 |
| 2026-04-15 00:00 |
19:19:59.07 |
+16:17:28.1 |
HIP 94991 |
12.83 |
| 2026-04-15 12:00 |
19:19:58.93 |
+16:17:43.1 |
HIP 94991 |
12.58 |
| 2026-04-16 00:00 |
19:19:58.78 |
+16:17:58.0 |
HIP 94991 |
12.33 |