C/1931 P1 (Ryves)
| 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) |
| 2026-02-03 00:00 |
07:50:20.78 |
+18:23:35.0 |
HIP 38332 |
19.88 |
| 2026-02-03 12:00 |
07:50:19.63 |
+18:23:38.3 |
HIP 38332 |
19.99 |
| 2026-02-04 00:00 |
07:50:18.49 |
+18:23:41.6 |
HIP 38332 |
20.10 |
| 2026-02-04 12:00 |
07:50:17.34 |
+18:23:45.0 |
HIP 38332 |
20.21 |
| 2026-02-05 00:00 |
07:50:16.21 |
+18:23:48.3 |
HIP 38332 |
20.32 |
| 2026-02-05 12:00 |
07:50:15.07 |
+18:23:51.6 |
HIP 38332 |
20.44 |
| 2026-02-06 00:00 |
07:50:13.94 |
+18:23:54.9 |
HIP 38332 |
20.55 |
| 2026-02-06 12:00 |
07:50:12.81 |
+18:23:58.2 |
HIP 38332 |
20.68 |
| 2026-02-07 00:00 |
07:50:11.68 |
+18:24:01.5 |
HIP 38332 |
20.80 |
| 2026-02-07 12:00 |
07:50:10.56 |
+18:24:04.8 |
HIP 38332 |
20.92 |
| 2026-02-08 00:00 |
07:50:09.45 |
+18:24:08.1 |
HIP 38332 |
21.05 |
| 2026-02-08 12:00 |
07:50:08.34 |
+18:24:11.3 |
HIP 38332 |
21.18 |
| 2026-02-09 00:00 |
07:50:07.23 |
+18:24:14.6 |
HIP 38332 |
21.31 |
| 2026-02-09 12:00 |
07:50:06.12 |
+18:24:17.9 |
HIP 38332 |
21.45 |
| 2026-02-10 00:00 |
07:50:05.03 |
+18:24:21.1 |
HIP 38135 |
21.30 |
| 2026-02-10 12:00 |
07:50:03.93 |
+18:24:24.4 |
HIP 38135 |
21.13 |
| 2026-02-11 00:00 |
07:50:02.84 |
+18:24:27.7 |
HIP 38135 |
20.96 |
| 2026-02-11 12:00 |
07:50:01.76 |
+18:24:30.9 |
HIP 38135 |
20.79 |
| 2026-02-12 00:00 |
07:50:00.68 |
+18:24:34.1 |
HIP 38135 |
20.63 |
| 2026-02-12 12:00 |
07:49:59.60 |
+18:24:37.4 |
HIP 38135 |
20.47 |
| 2026-02-13 00:00 |
07:49:58.53 |
+18:24:40.6 |
HIP 38135 |
20.31 |
| 2026-02-13 12:00 |
07:49:57.46 |
+18:24:43.8 |
HIP 38135 |
20.15 |
| 2026-02-14 00:00 |
07:49:56.40 |
+18:24:47.0 |
HIP 38135 |
20.00 |
| 2026-02-14 12:00 |
07:49:55.35 |
+18:24:50.2 |
HIP 38135 |
19.85 |
| 2026-02-15 00:00 |
07:49:54.30 |
+18:24:53.4 |
HIP 38135 |
19.70 |
| 2026-02-15 12:00 |
07:49:53.25 |
+18:24:56.6 |
HIP 38135 |
19.56 |
| 2026-02-16 00:00 |
07:49:52.22 |
+18:24:59.8 |
HIP 38135 |
19.42 |
| 2026-02-16 12:00 |
07:49:51.18 |
+18:25:02.9 |
HIP 38135 |
19.28 |
| 2026-02-17 00:00 |
07:49:50.15 |
+18:25:06.1 |
HIP 38135 |
19.15 |
| 2026-02-17 12:00 |
07:49:49.13 |
+18:25:09.2 |
HIP 38135 |
19.02 |
| 2026-02-18 00:00 |
07:49:48.12 |
+18:25:12.4 |
HIP 38135 |
18.89 |
| 2026-02-18 12:00 |
07:49:47.11 |
+18:25:15.5 |
HIP 38135 |
18.76 |
| 2026-02-19 00:00 |
07:49:46.10 |
+18:25:18.6 |
HIP 38135 |
18.64 |
| 2026-02-19 12:00 |
07:49:45.10 |
+18:25:21.7 |
HIP 38135 |
18.52 |
| 2026-02-20 00:00 |
07:49:44.11 |
+18:25:24.8 |
HIP 38135 |
18.41 |
| 2026-02-20 12:00 |
07:49:43.13 |
+18:25:27.9 |
HIP 38135 |
18.30 |
| 2026-02-21 00:00 |
07:49:42.15 |
+18:25:31.0 |
HIP 38135 |
18.19 |
| 2026-02-21 12:00 |
07:49:41.17 |
+18:25:34.0 |
HIP 38135 |
18.08 |
| 2026-02-22 00:00 |
07:49:40.21 |
+18:25:37.1 |
HIP 38135 |
17.98 |
| 2026-02-22 12:00 |
07:49:39.25 |
+18:25:40.1 |
HIP 38135 |
17.88 |
| 2026-02-23 00:00 |
07:49:38.29 |
+18:25:43.1 |
HIP 38135 |
17.79 |
| 2026-02-23 12:00 |
07:49:37.35 |
+18:25:46.1 |
HIP 38135 |
17.70 |
| 2026-02-24 00:00 |
07:49:36.41 |
+18:25:49.1 |
HIP 38135 |
17.61 |