| Parameter |
Value |
| Designation |
C/1975 E1 (Bradfield) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1975-04-04T13:55:24.000960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:24Z |
| Obs used |
52 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1975-06-11.0000000 |
| e |
1.00140639 |
| q (au) |
1.216946 |
| a (au) |
-865.298894 |
| i (deg) |
55.243879 |
| Ω (om, deg) |
157.908852 |
| ω (w, deg) |
264.130708 |
| M (ma, deg) |
0.002611 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.105 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.105 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.804 |
| k |
0.800 |
| 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) |
| 2026-06-01 00:00 |
15:20:54.74 |
+34:46:02.3 |
HIP 75326 |
31.66 |
| 2026-06-01 12:00 |
15:20:53.06 |
+34:46:00.2 |
HIP 75326 |
32.01 |
| 2026-06-02 00:00 |
15:20:51.39 |
+34:45:57.9 |
HIP 75326 |
32.35 |
| 2026-06-02 12:00 |
15:20:49.72 |
+34:45:55.5 |
HIP 75326 |
32.70 |
| 2026-06-03 00:00 |
15:20:48.05 |
+34:45:52.9 |
HIP 75326 |
33.04 |
| 2026-06-03 12:00 |
15:20:46.39 |
+34:45:50.1 |
HIP 75326 |
33.38 |
| 2026-06-04 00:00 |
15:20:44.74 |
+34:45:47.2 |
HIP 75326 |
33.72 |
| 2026-06-04 12:00 |
15:20:43.09 |
+34:45:44.1 |
HIP 75326 |
34.07 |
| 2026-06-05 00:00 |
15:20:41.45 |
+34:45:40.9 |
HIP 75326 |
34.41 |
| 2026-06-05 12:00 |
15:20:39.81 |
+34:45:37.5 |
HIP 75326 |
34.75 |
| 2026-06-06 00:00 |
15:20:38.18 |
+34:45:34.0 |
HIP 75326 |
35.09 |
| 2026-06-06 12:00 |
15:20:36.56 |
+34:45:30.3 |
HIP 75326 |
35.43 |
| 2026-06-07 00:00 |
15:20:34.94 |
+34:45:26.5 |
HIP 75326 |
35.77 |
| 2026-06-07 12:00 |
15:20:33.33 |
+34:45:22.5 |
HIP 75326 |
36.10 |
| 2026-06-08 00:00 |
15:20:31.72 |
+34:45:18.3 |
HIP 75326 |
36.44 |
| 2026-06-08 12:00 |
15:20:30.12 |
+34:45:14.0 |
HIP 75326 |
36.78 |
| 2026-06-09 00:00 |
15:20:28.53 |
+34:45:09.5 |
HIP 75326 |
37.11 |
| 2026-06-09 12:00 |
15:20:26.94 |
+34:45:04.9 |
HIP 75326 |
37.45 |
| 2026-06-10 00:00 |
15:20:25.36 |
+34:45:00.2 |
HIP 75326 |
37.78 |
| 2026-06-10 12:00 |
15:20:23.79 |
+34:44:55.2 |
HIP 75326 |
38.11 |
| 2026-06-11 00:00 |
15:20:22.22 |
+34:44:50.2 |
HIP 75326 |
38.45 |
| 2026-06-11 12:00 |
15:20:20.66 |
+34:44:44.9 |
HIP 75326 |
38.78 |
| 2026-06-12 00:00 |
15:20:19.11 |
+34:44:39.5 |
HIP 75326 |
39.11 |
| 2026-06-12 12:00 |
15:20:17.57 |
+34:44:34.0 |
HIP 75326 |
39.44 |
| 2026-06-13 00:00 |
15:20:16.03 |
+34:44:28.3 |
HIP 75326 |
39.76 |
| 2026-06-13 12:00 |
15:20:14.50 |
+34:44:22.5 |
HIP 75326 |
40.09 |
| 2026-06-14 00:00 |
15:20:12.98 |
+34:44:16.5 |
HIP 75326 |
40.42 |
| 2026-06-14 12:00 |
15:20:11.47 |
+34:44:10.4 |
HIP 74833 |
40.55 |
| 2026-06-15 00:00 |
15:20:09.97 |
+34:44:04.1 |
HIP 74833 |
40.38 |
| 2026-06-15 12:00 |
15:20:08.47 |
+34:43:57.6 |
HIP 74833 |
40.21 |
| 2026-06-16 00:00 |
15:20:06.98 |
+34:43:51.0 |
HIP 74833 |
40.05 |
| 2026-06-16 12:00 |
15:20:05.50 |
+34:43:44.3 |
HIP 74833 |
39.89 |
| 2026-06-17 00:00 |
15:20:04.03 |
+34:43:37.4 |
HIP 74833 |
39.73 |
| 2026-06-17 12:00 |
15:20:02.57 |
+34:43:30.4 |
HIP 74833 |
39.58 |
| 2026-06-18 00:00 |
15:20:01.11 |
+34:43:23.2 |
HIP 74833 |
39.44 |
| 2026-06-18 12:00 |
15:19:59.67 |
+34:43:15.9 |
HIP 74833 |
39.30 |
| 2026-06-19 00:00 |
15:19:58.23 |
+34:43:08.4 |
HIP 74833 |
39.17 |
| 2026-06-19 12:00 |
15:19:56.81 |
+34:43:00.8 |
HIP 74833 |
39.04 |
| 2026-06-20 00:00 |
15:19:55.39 |
+34:42:53.1 |
HIP 74833 |
38.91 |
| 2026-06-20 12:00 |
15:19:53.98 |
+34:42:45.2 |
HIP 74833 |
38.80 |
| 2026-06-21 00:00 |
15:19:52.58 |
+34:42:37.1 |
HIP 74833 |
38.68 |
| 2026-06-21 12:00 |
15:19:51.19 |
+34:42:29.0 |
HIP 74833 |
38.57 |
| 2026-06-22 00:00 |
15:19:49.81 |
+34:42:20.6 |
HIP 74833 |
38.47 |