| 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) |
| 2026-07-29 00:00 |
19:15:43.17 |
+16:36:07.7 |
HIP 94607 |
23.45 |
| 2026-07-29 12:00 |
19:15:41.58 |
+16:36:00.1 |
HIP 94607 |
23.44 |
| 2026-07-30 00:00 |
19:15:40.00 |
+16:35:52.5 |
HIP 94607 |
23.44 |
| 2026-07-30 12:00 |
19:15:38.42 |
+16:35:44.7 |
HIP 94607 |
23.45 |
| 2026-07-31 00:00 |
19:15:36.84 |
+16:35:36.8 |
HIP 94607 |
23.47 |
| 2026-07-31 12:00 |
19:15:35.27 |
+16:35:28.8 |
HIP 94607 |
23.50 |
| 2026-08-01 00:00 |
19:15:33.71 |
+16:35:20.7 |
HIP 94607 |
23.54 |
| 2026-08-01 12:00 |
19:15:32.15 |
+16:35:12.5 |
HIP 94607 |
23.58 |
| 2026-08-02 00:00 |
19:15:30.60 |
+16:35:04.1 |
HIP 94607 |
23.64 |
| 2026-08-02 12:00 |
19:15:29.05 |
+16:34:55.7 |
HIP 94606 |
23.60 |
| 2026-08-03 00:00 |
19:15:27.51 |
+16:34:47.1 |
HIP 94606 |
23.39 |
| 2026-08-03 12:00 |
19:15:25.97 |
+16:34:38.4 |
HIP 94606 |
23.18 |
| 2026-08-04 00:00 |
19:15:24.44 |
+16:34:29.6 |
HIP 94606 |
22.97 |
| 2026-08-04 12:00 |
19:15:22.92 |
+16:34:20.7 |
HIP 94606 |
22.77 |
| 2026-08-05 00:00 |
19:15:21.40 |
+16:34:11.7 |
HIP 94606 |
22.57 |
| 2026-08-05 12:00 |
19:15:19.89 |
+16:34:02.5 |
HIP 94606 |
22.37 |
| 2026-08-06 00:00 |
19:15:18.38 |
+16:33:53.3 |
HIP 94606 |
22.18 |
| 2026-08-06 12:00 |
19:15:16.88 |
+16:33:43.9 |
HIP 94606 |
21.99 |
| 2026-08-07 00:00 |
19:15:15.39 |
+16:33:34.5 |
HIP 94606 |
21.80 |
| 2026-08-07 12:00 |
19:15:13.90 |
+16:33:24.9 |
HIP 94606 |
21.62 |
| 2026-08-08 00:00 |
19:15:12.42 |
+16:33:15.2 |
HIP 94606 |
21.44 |
| 2026-08-08 12:00 |
19:15:10.95 |
+16:33:05.4 |
HIP 94606 |
21.26 |
| 2026-08-09 00:00 |
19:15:09.49 |
+16:32:55.5 |
HIP 94606 |
21.09 |
| 2026-08-09 12:00 |
19:15:08.03 |
+16:32:45.5 |
HIP 94606 |
20.93 |
| 2026-08-10 00:00 |
19:15:06.58 |
+16:32:35.4 |
HIP 94606 |
20.77 |
| 2026-08-10 12:00 |
19:15:05.13 |
+16:32:25.2 |
HIP 94606 |
20.61 |
| 2026-08-11 00:00 |
19:15:03.70 |
+16:32:14.9 |
HIP 94606 |
20.45 |
| 2026-08-11 12:00 |
19:15:02.27 |
+16:32:04.4 |
HIP 94606 |
20.30 |
| 2026-08-12 00:00 |
19:15:00.85 |
+16:31:53.9 |
HIP 94606 |
20.16 |
| 2026-08-12 12:00 |
19:14:59.44 |
+16:31:43.3 |
HIP 94606 |
20.02 |
| 2026-08-13 00:00 |
19:14:58.03 |
+16:31:32.6 |
HIP 94606 |
19.88 |
| 2026-08-13 12:00 |
19:14:56.63 |
+16:31:21.8 |
HIP 94606 |
19.75 |
| 2026-08-14 00:00 |
19:14:55.24 |
+16:31:10.8 |
HIP 94606 |
19.62 |
| 2026-08-14 12:00 |
19:14:53.86 |
+16:30:59.8 |
HIP 94606 |
19.50 |
| 2026-08-15 00:00 |
19:14:52.49 |
+16:30:48.7 |
HIP 94606 |
19.38 |
| 2026-08-15 12:00 |
19:14:51.13 |
+16:30:37.5 |
HIP 94606 |
19.27 |
| 2026-08-16 00:00 |
19:14:49.77 |
+16:30:26.2 |
HIP 94606 |
19.16 |
| 2026-08-16 12:00 |
19:14:48.43 |
+16:30:14.8 |
HIP 94606 |
19.05 |
| 2026-08-17 00:00 |
19:14:47.09 |
+16:30:03.3 |
HIP 94606 |
18.95 |
| 2026-08-17 12:00 |
19:14:45.76 |
+16:29:51.7 |
HIP 94606 |
18.86 |
| 2026-08-18 00:00 |
19:14:44.44 |
+16:29:40.0 |
HIP 94606 |
18.77 |
| 2026-08-18 12:00 |
19:14:43.13 |
+16:29:28.2 |
HIP 94606 |
18.68 |
| 2026-08-19 00:00 |
19:14:41.83 |
+16:29:16.4 |
HIP 94606 |
18.60 |