| Parameter |
Value |
| Designation |
C/1978 C1 (Bradfield) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1978-03-17T16:34:51.617280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:27Z |
| Obs used |
73 |
| NEO |
- |
| M1 |
6.800 |
| K1 |
9.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1978-02-23.0000000 |
| e |
1.00000000 |
| q (au) |
0.436574 |
| a (au) |
- |
| i (deg) |
51.086724 |
| Ω (om, deg) |
260.497948 |
| ω (w, deg) |
48.706509 |
| M (ma, deg) |
- |
Magnitude
Scatter + Global Linear
$$
M_a = (7.306 + 3.467\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.306 |
| n |
3.467 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.971 |
| 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) |
| 2026-09-20 00:00 |
07:06:27.45 |
-07:25:39.7 |
HIP 34279 |
7.09 |
| 2026-09-20 12:00 |
07:06:27.93 |
-07:25:51.9 |
HIP 34279 |
7.31 |
| 2026-09-21 00:00 |
07:06:28.40 |
-07:26:04.1 |
HIP 34279 |
7.54 |
| 2026-09-21 12:00 |
07:06:28.86 |
-07:26:16.4 |
HIP 34279 |
7.76 |
| 2026-09-22 00:00 |
07:06:29.30 |
-07:26:28.6 |
HIP 34279 |
7.98 |
| 2026-09-22 12:00 |
07:06:29.74 |
-07:26:40.9 |
HIP 34279 |
8.21 |
| 2026-09-23 00:00 |
07:06:30.16 |
-07:26:53.2 |
HIP 34279 |
8.43 |
| 2026-09-23 12:00 |
07:06:30.56 |
-07:27:05.5 |
HIP 34279 |
8.65 |
| 2026-09-24 00:00 |
07:06:30.96 |
-07:27:17.8 |
HIP 34326 |
8.82 |
| 2026-09-24 12:00 |
07:06:31.34 |
-07:27:30.1 |
HIP 34326 |
8.61 |
| 2026-09-25 00:00 |
07:06:31.71 |
-07:27:42.4 |
HIP 34326 |
8.40 |
| 2026-09-25 12:00 |
07:06:32.06 |
-07:27:54.7 |
HIP 34326 |
8.20 |
| 2026-09-26 00:00 |
07:06:32.40 |
-07:28:07.1 |
HIP 34326 |
8.00 |
| 2026-09-26 12:00 |
07:06:32.73 |
-07:28:19.4 |
HIP 34326 |
7.80 |
| 2026-09-27 00:00 |
07:06:33.04 |
-07:28:31.7 |
HIP 34326 |
7.61 |
| 2026-09-27 12:00 |
07:06:33.35 |
-07:28:44.1 |
HIP 34326 |
7.42 |
| 2026-09-28 00:00 |
07:06:33.63 |
-07:28:56.4 |
HIP 34326 |
7.23 |
| 2026-09-28 12:00 |
07:06:33.91 |
-07:29:08.8 |
HIP 34326 |
7.05 |
| 2026-09-29 00:00 |
07:06:34.17 |
-07:29:21.1 |
HIP 34326 |
6.88 |
| 2026-09-29 12:00 |
07:06:34.42 |
-07:29:33.5 |
HIP 34326 |
6.71 |
| 2026-09-30 00:00 |
07:06:34.66 |
-07:29:45.8 |
HIP 34326 |
6.54 |
| 2026-09-30 12:00 |
07:06:34.88 |
-07:29:58.1 |
HIP 34326 |
6.38 |
| 2026-10-01 00:00 |
07:06:35.09 |
-07:30:10.5 |
HIP 34326 |
6.23 |
| 2026-10-01 12:00 |
07:06:35.28 |
-07:30:22.8 |
HIP 34326 |
6.08 |
| 2026-10-02 00:00 |
07:06:35.46 |
-07:30:35.2 |
HIP 34326 |
5.94 |
| 2026-10-02 12:00 |
07:06:35.63 |
-07:30:47.5 |
HIP 34326 |
5.81 |
| 2026-10-03 00:00 |
07:06:35.79 |
-07:30:59.8 |
HIP 34326 |
5.68 |
| 2026-10-03 12:00 |
07:06:35.93 |
-07:31:12.1 |
HIP 34326 |
5.56 |
| 2026-10-04 00:00 |
07:06:36.06 |
-07:31:24.4 |
HIP 34326 |
5.45 |
| 2026-10-04 12:00 |
07:06:36.17 |
-07:31:36.7 |
HIP 34326 |
5.35 |
| 2026-10-05 00:00 |
07:06:36.27 |
-07:31:49.0 |
HIP 34326 |
5.26 |
| 2026-10-05 12:00 |
07:06:36.36 |
-07:32:01.3 |
HIP 34326 |
5.18 |
| 2026-10-06 00:00 |
07:06:36.43 |
-07:32:13.6 |
HIP 34326 |
5.11 |
| 2026-10-06 12:00 |
07:06:36.49 |
-07:32:25.8 |
HIP 34326 |
5.06 |
| 2026-10-07 00:00 |
07:06:36.54 |
-07:32:38.1 |
HIP 34326 |
5.01 |
| 2026-10-07 12:00 |
07:06:36.57 |
-07:32:50.3 |
HIP 34326 |
4.97 |
| 2026-10-08 00:00 |
07:06:36.59 |
-07:33:02.5 |
HIP 34326 |
4.95 |
| 2026-10-08 12:00 |
07:06:36.59 |
-07:33:14.7 |
HIP 34326 |
4.93 |
| 2026-10-09 00:00 |
07:06:36.58 |
-07:33:26.9 |
HIP 34326 |
4.93 |
| 2026-10-09 12:00 |
07:06:36.56 |
-07:33:39.0 |
HIP 34326 |
4.94 |
| 2026-10-10 00:00 |
07:06:36.52 |
-07:33:51.2 |
HIP 34326 |
4.96 |
| 2026-10-10 12:00 |
07:06:36.47 |
-07:34:03.3 |
HIP 34326 |
5.00 |
| 2026-10-11 00:00 |
07:06:36.40 |
-07:34:15.4 |
HIP 34326 |
5.04 |