| 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) |
| 2026-03-26 00:00 |
07:00:21.79 |
-07:26:51.5 |
HIP 33628 |
27.00 |
| 2026-03-26 12:00 |
07:00:21.54 |
-07:26:39.4 |
HIP 33628 |
26.81 |
| 2026-03-27 00:00 |
07:00:21.30 |
-07:26:27.3 |
HIP 33628 |
26.62 |
| 2026-03-27 12:00 |
07:00:21.08 |
-07:26:15.2 |
HIP 33628 |
26.43 |
| 2026-03-28 00:00 |
07:00:20.87 |
-07:26:03.2 |
HIP 33628 |
26.25 |
| 2026-03-28 12:00 |
07:00:20.67 |
-07:25:51.1 |
HIP 33628 |
26.06 |
| 2026-03-29 00:00 |
07:00:20.49 |
-07:25:39.1 |
HIP 33628 |
25.89 |
| 2026-03-29 12:00 |
07:00:20.32 |
-07:25:27.0 |
HIP 33628 |
25.71 |
| 2026-03-30 00:00 |
07:00:20.16 |
-07:25:15.0 |
HIP 33628 |
25.54 |
| 2026-03-30 12:00 |
07:00:20.02 |
-07:25:03.0 |
HIP 33628 |
25.37 |
| 2026-03-31 00:00 |
07:00:19.90 |
-07:24:51.0 |
HIP 33628 |
25.20 |
| 2026-03-31 12:00 |
07:00:19.78 |
-07:24:39.0 |
HIP 33628 |
25.03 |
| 2026-04-01 00:00 |
07:00:19.68 |
-07:24:27.0 |
HIP 33628 |
24.87 |
| 2026-04-01 12:00 |
07:00:19.60 |
-07:24:15.0 |
HIP 33628 |
24.71 |
| 2026-04-02 00:00 |
07:00:19.52 |
-07:24:03.1 |
HIP 33628 |
24.56 |
| 2026-04-02 12:00 |
07:00:19.47 |
-07:23:51.2 |
HIP 33628 |
24.41 |
| 2026-04-03 00:00 |
07:00:19.42 |
-07:23:39.3 |
HIP 33628 |
24.26 |
| 2026-04-03 12:00 |
07:00:19.39 |
-07:23:27.4 |
HIP 33628 |
24.12 |
| 2026-04-04 00:00 |
07:00:19.37 |
-07:23:15.5 |
HIP 33628 |
23.97 |
| 2026-04-04 12:00 |
07:00:19.37 |
-07:23:03.7 |
HIP 33628 |
23.84 |
| 2026-04-05 00:00 |
07:00:19.38 |
-07:22:51.9 |
HIP 33628 |
23.70 |
| 2026-04-05 12:00 |
07:00:19.40 |
-07:22:40.1 |
HIP 33628 |
23.57 |
| 2026-04-06 00:00 |
07:00:19.44 |
-07:22:28.3 |
HIP 33628 |
23.44 |
| 2026-04-06 12:00 |
07:00:19.49 |
-07:22:16.5 |
HIP 33628 |
23.32 |
| 2026-04-07 00:00 |
07:00:19.56 |
-07:22:04.8 |
HIP 33628 |
23.20 |
| 2026-04-07 12:00 |
07:00:19.64 |
-07:21:53.1 |
HIP 33628 |
23.09 |
| 2026-04-08 00:00 |
07:00:19.73 |
-07:21:41.4 |
HIP 33628 |
22.97 |
| 2026-04-08 12:00 |
07:00:19.84 |
-07:21:29.8 |
HIP 33628 |
22.87 |
| 2026-04-09 00:00 |
07:00:19.96 |
-07:21:18.2 |
HIP 33628 |
22.76 |
| 2026-04-09 12:00 |
07:00:20.09 |
-07:21:06.6 |
HIP 33628 |
22.66 |
| 2026-04-10 00:00 |
07:00:20.24 |
-07:20:55.0 |
HIP 33628 |
22.57 |
| 2026-04-10 12:00 |
07:00:20.40 |
-07:20:43.5 |
HIP 33628 |
22.48 |
| 2026-04-11 00:00 |
07:00:20.58 |
-07:20:32.0 |
HIP 33628 |
22.39 |
| 2026-04-11 12:00 |
07:00:20.76 |
-07:20:20.5 |
HIP 33628 |
22.31 |
| 2026-04-12 00:00 |
07:00:20.97 |
-07:20:09.1 |
HIP 33628 |
22.23 |
| 2026-04-12 12:00 |
07:00:21.18 |
-07:19:57.7 |
HIP 33628 |
22.16 |
| 2026-04-13 00:00 |
07:00:21.41 |
-07:19:46.4 |
HIP 33628 |
22.09 |
| 2026-04-13 12:00 |
07:00:21.65 |
-07:19:35.0 |
HIP 33628 |
22.03 |
| 2026-04-14 00:00 |
07:00:21.91 |
-07:19:23.7 |
HIP 33628 |
21.97 |
| 2026-04-14 12:00 |
07:00:22.18 |
-07:19:12.5 |
HIP 33628 |
21.91 |
| 2026-04-15 00:00 |
07:00:22.46 |
-07:19:01.3 |
HIP 33628 |
21.86 |
| 2026-04-15 12:00 |
07:00:22.76 |
-07:18:50.1 |
HIP 33628 |
21.82 |
| 2026-04-16 00:00 |
07:00:23.07 |
-07:18:39.0 |
HIP 33628 |
21.78 |