| Parameter |
Value |
| Designation |
C/1931 P1 (Ryves) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1931-08-25T21:54:00Z |
| Orbit solution date (soln_date, UTC) |
- |
| Obs used |
25 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1931-08-07.0000000 |
| e |
0.99932600 |
| q (au) |
0.074924 |
| a (au) |
111.163205 |
| i (deg) |
169.288100 |
| Ω (om, deg) |
102.277600 |
| ω (w, deg) |
168.145500 |
| M (ma, deg) |
-0.015904 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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 |
07:53:00.34 |
+18:18:39.4 |
HIP 38648 |
28.80 |
| 2026-09-20 12:00 |
07:53:00.88 |
+18:18:37.2 |
HIP 38648 |
28.67 |
| 2026-09-21 00:00 |
07:53:01.42 |
+18:18:35.1 |
HIP 38648 |
28.54 |
| 2026-09-21 12:00 |
07:53:01.95 |
+18:18:33.0 |
HIP 38648 |
28.41 |
| 2026-09-22 00:00 |
07:53:02.47 |
+18:18:30.9 |
HIP 38648 |
28.28 |
| 2026-09-22 12:00 |
07:53:02.98 |
+18:18:28.8 |
HIP 38648 |
28.16 |
| 2026-09-23 00:00 |
07:53:03.49 |
+18:18:26.8 |
HIP 38648 |
28.04 |
| 2026-09-23 12:00 |
07:53:03.98 |
+18:18:24.8 |
HIP 38648 |
27.92 |
| 2026-09-24 00:00 |
07:53:04.47 |
+18:18:22.8 |
HIP 38648 |
27.80 |
| 2026-09-24 12:00 |
07:53:04.94 |
+18:18:20.8 |
HIP 38648 |
27.68 |
| 2026-09-25 00:00 |
07:53:05.41 |
+18:18:18.8 |
HIP 38648 |
27.57 |
| 2026-09-25 12:00 |
07:53:05.87 |
+18:18:16.9 |
HIP 38648 |
27.46 |
| 2026-09-26 00:00 |
07:53:06.32 |
+18:18:14.9 |
HIP 38648 |
27.35 |
| 2026-09-26 12:00 |
07:53:06.76 |
+18:18:13.1 |
HIP 38648 |
27.24 |
| 2026-09-27 00:00 |
07:53:07.19 |
+18:18:11.2 |
HIP 38648 |
27.13 |
| 2026-09-27 12:00 |
07:53:07.62 |
+18:18:09.3 |
HIP 38648 |
27.03 |
| 2026-09-28 00:00 |
07:53:08.03 |
+18:18:07.5 |
HIP 38648 |
26.93 |
| 2026-09-28 12:00 |
07:53:08.44 |
+18:18:05.7 |
HIP 38648 |
26.83 |
| 2026-09-29 00:00 |
07:53:08.83 |
+18:18:03.9 |
HIP 38648 |
26.73 |
| 2026-09-29 12:00 |
07:53:09.22 |
+18:18:02.1 |
HIP 38648 |
26.64 |
| 2026-09-30 00:00 |
07:53:09.59 |
+18:18:00.4 |
HIP 38648 |
26.55 |
| 2026-09-30 12:00 |
07:53:09.96 |
+18:17:58.7 |
HIP 38648 |
26.45 |
| 2026-10-01 00:00 |
07:53:10.32 |
+18:17:57.0 |
HIP 38648 |
26.37 |
| 2026-10-01 12:00 |
07:53:10.67 |
+18:17:55.3 |
HIP 38648 |
26.28 |
| 2026-10-02 00:00 |
07:53:11.01 |
+18:17:53.7 |
HIP 38648 |
26.20 |
| 2026-10-02 12:00 |
07:53:11.34 |
+18:17:52.1 |
HIP 38648 |
26.11 |
| 2026-10-03 00:00 |
07:53:11.66 |
+18:17:50.5 |
HIP 38648 |
26.03 |
| 2026-10-03 12:00 |
07:53:11.97 |
+18:17:48.9 |
HIP 38648 |
25.96 |
| 2026-10-04 00:00 |
07:53:12.27 |
+18:17:47.3 |
HIP 38648 |
25.88 |
| 2026-10-04 12:00 |
07:53:12.56 |
+18:17:45.8 |
HIP 38648 |
25.81 |
| 2026-10-05 00:00 |
07:53:12.84 |
+18:17:44.3 |
HIP 38648 |
25.74 |
| 2026-10-05 12:00 |
07:53:13.11 |
+18:17:42.8 |
HIP 38648 |
25.67 |
| 2026-10-06 00:00 |
07:53:13.38 |
+18:17:41.4 |
HIP 38648 |
25.60 |
| 2026-10-06 12:00 |
07:53:13.63 |
+18:17:39.9 |
HIP 38648 |
25.54 |
| 2026-10-07 00:00 |
07:53:13.87 |
+18:17:38.5 |
HIP 38648 |
25.47 |
| 2026-10-07 12:00 |
07:53:14.11 |
+18:17:37.2 |
HIP 38648 |
25.41 |
| 2026-10-08 00:00 |
07:53:14.33 |
+18:17:35.8 |
HIP 38648 |
25.36 |
| 2026-10-08 12:00 |
07:53:14.54 |
+18:17:34.5 |
HIP 38648 |
25.30 |
| 2026-10-09 00:00 |
07:53:14.75 |
+18:17:33.2 |
HIP 38648 |
25.25 |
| 2026-10-09 12:00 |
07:53:14.94 |
+18:17:31.9 |
HIP 38648 |
25.20 |
| 2026-10-10 00:00 |
07:53:15.12 |
+18:17:30.7 |
HIP 38648 |
25.15 |
| 2026-10-10 12:00 |
07:53:15.30 |
+18:17:29.4 |
HIP 38648 |
25.10 |
| 2026-10-11 00:00 |
07:53:15.46 |
+18:17:28.2 |
HIP 38648 |
25.06 |