| Parameter |
Value |
| Designation |
C/1975 V2 (Bradfield) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1975-12-21T04:20:57.010560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:24Z |
| Obs used |
81 |
| NEO |
- |
| M1 |
10.400 |
| K1 |
16.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1975-12-22.0000000 |
| e |
1.00001538 |
| q (au) |
0.218721 |
| a (au) |
-14217.185675 |
| i (deg) |
70.626160 |
| Ω (om, deg) |
271.312759 |
| ω (w, deg) |
358.089866 |
| M (ma, deg) |
0.000000 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.332 + 3.967\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.332 |
| n |
3.967 |
| gf |
0.800 |
| gb |
-0.640 |
| 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) |
| 2026-05-12 00:00 |
05:51:07.52 |
+30:47:55.7 |
HIP 27675 |
11.49 |
| 2026-05-12 12:00 |
05:51:08.94 |
+30:47:54.0 |
HIP 27675 |
11.33 |
| 2026-05-13 00:00 |
05:51:10.37 |
+30:47:52.3 |
HIP 27675 |
11.17 |
| 2026-05-13 12:00 |
05:51:11.81 |
+30:47:50.6 |
HIP 27675 |
11.03 |
| 2026-05-14 00:00 |
05:51:13.25 |
+30:47:49.0 |
HIP 27675 |
10.89 |
| 2026-05-14 12:00 |
05:51:14.70 |
+30:47:47.4 |
HIP 27675 |
10.75 |
| 2026-05-15 00:00 |
05:51:16.16 |
+30:47:45.8 |
HIP 27675 |
10.63 |
| 2026-05-15 12:00 |
05:51:17.63 |
+30:47:44.2 |
HIP 27675 |
10.51 |
| 2026-05-16 00:00 |
05:51:19.11 |
+30:47:42.7 |
HIP 27675 |
10.40 |
| 2026-05-16 12:00 |
05:51:20.60 |
+30:47:41.1 |
HIP 27675 |
10.29 |
| 2026-05-17 00:00 |
05:51:22.09 |
+30:47:39.6 |
HIP 27675 |
10.20 |
| 2026-05-17 12:00 |
05:51:23.60 |
+30:47:38.1 |
HIP 27675 |
10.12 |
| 2026-05-18 00:00 |
05:51:25.11 |
+30:47:36.7 |
HIP 27675 |
10.04 |
| 2026-05-18 12:00 |
05:51:26.62 |
+30:47:35.2 |
HIP 27675 |
9.98 |
| 2026-05-19 00:00 |
05:51:28.15 |
+30:47:33.8 |
HIP 27675 |
9.93 |
| 2026-05-19 12:00 |
05:51:29.68 |
+30:47:32.4 |
HIP 27675 |
9.89 |
| 2026-05-20 00:00 |
05:51:31.22 |
+30:47:31.0 |
HIP 27675 |
9.86 |
| 2026-05-20 12:00 |
05:51:32.77 |
+30:47:29.7 |
HIP 27675 |
9.84 |
| 2026-05-21 00:00 |
05:51:34.32 |
+30:47:28.3 |
HIP 27675 |
9.83 |
| 2026-05-21 12:00 |
05:51:35.88 |
+30:47:27.0 |
HIP 27675 |
9.84 |
| 2026-05-22 00:00 |
05:51:37.45 |
+30:47:25.8 |
HIP 27675 |
9.85 |
| 2026-05-22 12:00 |
05:51:39.02 |
+30:47:24.5 |
HIP 27675 |
9.88 |
| 2026-05-23 00:00 |
05:51:40.60 |
+30:47:23.2 |
HIP 27675 |
9.92 |
| 2026-05-23 12:00 |
05:51:42.19 |
+30:47:22.0 |
HIP 27675 |
9.98 |
| 2026-05-24 00:00 |
05:51:43.78 |
+30:47:20.8 |
HIP 27675 |
10.04 |
| 2026-05-24 12:00 |
05:51:45.38 |
+30:47:19.7 |
HIP 27675 |
10.12 |
| 2026-05-25 00:00 |
05:51:46.99 |
+30:47:18.5 |
HIP 27675 |
10.21 |
| 2026-05-25 12:00 |
05:51:48.60 |
+30:47:17.4 |
HIP 27675 |
10.31 |
| 2026-05-26 00:00 |
05:51:50.22 |
+30:47:16.3 |
HIP 27675 |
10.42 |
| 2026-05-26 12:00 |
05:51:51.84 |
+30:47:15.2 |
HIP 27675 |
10.54 |
| 2026-05-27 00:00 |
05:51:53.47 |
+30:47:14.1 |
HIP 27675 |
10.68 |
| 2026-05-27 12:00 |
05:51:55.10 |
+30:47:13.1 |
HIP 27675 |
10.82 |
| 2026-05-28 00:00 |
05:51:56.74 |
+30:47:12.1 |
HIP 27675 |
10.98 |
| 2026-05-28 12:00 |
05:51:58.39 |
+30:47:11.1 |
HIP 27675 |
11.14 |
| 2026-05-29 00:00 |
05:52:00.04 |
+30:47:10.1 |
HIP 27675 |
11.32 |
| 2026-05-29 12:00 |
05:52:01.70 |
+30:47:09.2 |
HIP 27675 |
11.50 |
| 2026-05-30 00:00 |
05:52:03.36 |
+30:47:08.2 |
HIP 27675 |
11.69 |
| 2026-05-30 12:00 |
05:52:05.02 |
+30:47:07.3 |
HIP 27675 |
11.89 |
| 2026-05-31 00:00 |
05:52:06.69 |
+30:47:06.5 |
HIP 27675 |
12.10 |
| 2026-05-31 12:00 |
05:52:08.37 |
+30:47:05.6 |
HIP 27675 |
12.32 |
| 2026-06-01 00:00 |
05:52:10.04 |
+30:47:04.8 |
HIP 27675 |
12.55 |
| 2026-06-01 12:00 |
05:52:11.73 |
+30:47:04.0 |
HIP 27675 |
12.78 |
| 2026-06-02 00:00 |
05:52:13.42 |
+30:47:03.2 |
HIP 27675 |
13.02 |