| Parameter |
Value |
| Designation |
C/1941 B1 (Friend-Reese-Honda) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1941-01-20T09:04:01.920000Z |
| Orbit solution date (soln_date, UTC) |
- |
| Obs used |
29 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1941-01-20.3778000 |
| e |
0.98122100 |
| q (au) |
0.941864 |
| a (au) |
50.155173 |
| i (deg) |
26.275600 |
| Ω (om, deg) |
329.789700 |
| ω (w, deg) |
132.731900 |
| M (ma, deg) |
0.000000 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.927 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.927 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.906 |
| 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 |
18:50:18.65 |
-43:37:42.6 |
HIP 92382 |
14.10 |
| 2026-09-20 12:00 |
18:50:18.22 |
-43:37:35.5 |
HIP 92382 |
13.95 |
| 2026-09-21 00:00 |
18:50:17.80 |
-43:37:28.3 |
HIP 92382 |
13.81 |
| 2026-09-21 12:00 |
18:50:17.39 |
-43:37:21.1 |
HIP 92382 |
13.67 |
| 2026-09-22 00:00 |
18:50:17.00 |
-43:37:13.9 |
HIP 92382 |
13.53 |
| 2026-09-22 12:00 |
18:50:16.63 |
-43:37:06.6 |
HIP 92382 |
13.40 |
| 2026-09-23 00:00 |
18:50:16.28 |
-43:36:59.4 |
HIP 92382 |
13.26 |
| 2026-09-23 12:00 |
18:50:15.94 |
-43:36:52.1 |
HIP 92382 |
13.12 |
| 2026-09-24 00:00 |
18:50:15.62 |
-43:36:44.7 |
HIP 92382 |
12.99 |
| 2026-09-24 12:00 |
18:50:15.32 |
-43:36:37.4 |
HIP 92382 |
12.86 |
| 2026-09-25 00:00 |
18:50:15.03 |
-43:36:30.0 |
HIP 92382 |
12.73 |
| 2026-09-25 12:00 |
18:50:14.76 |
-43:36:22.6 |
HIP 92382 |
12.60 |
| 2026-09-26 00:00 |
18:50:14.50 |
-43:36:15.1 |
HIP 92382 |
12.47 |
| 2026-09-26 12:00 |
18:50:14.27 |
-43:36:07.7 |
HIP 92382 |
12.35 |
| 2026-09-27 00:00 |
18:50:14.05 |
-43:36:00.2 |
HIP 92382 |
12.22 |
| 2026-09-27 12:00 |
18:50:13.84 |
-43:35:52.7 |
HIP 92382 |
12.10 |
| 2026-09-28 00:00 |
18:50:13.66 |
-43:35:45.2 |
HIP 92382 |
11.98 |
| 2026-09-28 12:00 |
18:50:13.49 |
-43:35:37.6 |
HIP 92382 |
11.86 |
| 2026-09-29 00:00 |
18:50:13.33 |
-43:35:30.1 |
HIP 92382 |
11.74 |
| 2026-09-29 12:00 |
18:50:13.20 |
-43:35:22.5 |
HIP 92382 |
11.62 |
| 2026-09-30 00:00 |
18:50:13.08 |
-43:35:14.9 |
HIP 92382 |
11.51 |
| 2026-09-30 12:00 |
18:50:12.97 |
-43:35:07.3 |
HIP 92382 |
11.39 |
| 2026-10-01 00:00 |
18:50:12.89 |
-43:34:59.6 |
HIP 92382 |
11.28 |
| 2026-10-01 12:00 |
18:50:12.82 |
-43:34:52.0 |
HIP 92382 |
11.18 |
| 2026-10-02 00:00 |
18:50:12.77 |
-43:34:44.3 |
HIP 92382 |
11.07 |
| 2026-10-02 12:00 |
18:50:12.73 |
-43:34:36.6 |
HIP 92382 |
10.96 |
| 2026-10-03 00:00 |
18:50:12.72 |
-43:34:28.9 |
HIP 92382 |
10.86 |
| 2026-10-03 12:00 |
18:50:12.72 |
-43:34:21.2 |
HIP 92382 |
10.76 |
| 2026-10-04 00:00 |
18:50:12.73 |
-43:34:13.4 |
HIP 92382 |
10.67 |
| 2026-10-04 12:00 |
18:50:12.77 |
-43:34:05.7 |
HIP 92382 |
10.57 |
| 2026-10-05 00:00 |
18:50:12.82 |
-43:33:57.9 |
HIP 92382 |
10.48 |
| 2026-10-05 12:00 |
18:50:12.88 |
-43:33:50.1 |
HIP 92382 |
10.39 |
| 2026-10-06 00:00 |
18:50:12.97 |
-43:33:42.3 |
HIP 92382 |
10.30 |
| 2026-10-06 12:00 |
18:50:13.07 |
-43:33:34.5 |
HIP 92382 |
10.22 |
| 2026-10-07 00:00 |
18:50:13.19 |
-43:33:26.7 |
HIP 92382 |
10.14 |
| 2026-10-07 12:00 |
18:50:13.32 |
-43:33:18.8 |
HIP 92382 |
10.06 |
| 2026-10-08 00:00 |
18:50:13.48 |
-43:33:11.0 |
HIP 92382 |
9.98 |
| 2026-10-08 12:00 |
18:50:13.65 |
-43:33:03.1 |
HIP 92382 |
9.91 |
| 2026-10-09 00:00 |
18:50:13.84 |
-43:32:55.3 |
HIP 92382 |
9.85 |
| 2026-10-09 12:00 |
18:50:14.04 |
-43:32:47.4 |
HIP 92382 |
9.78 |
| 2026-10-10 00:00 |
18:50:14.26 |
-43:32:39.5 |
HIP 92382 |
9.72 |
| 2026-10-10 12:00 |
18:50:14.50 |
-43:32:31.6 |
HIP 92382 |
9.66 |
| 2026-10-11 00:00 |
18:50:14.75 |
-43:32:23.7 |
HIP 92382 |
9.61 |