431P/Scotti
| Parameter |
Value |
| Designation |
431P/Scotti |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-09-09T08:10:57.241920Z |
| Orbit solution date (soln_date, UTC) |
2025-01-02T20:13:02Z |
| Obs used |
519 |
| NEO |
- |
| M1 |
12.000 |
| K1 |
19.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-08-07.0000000 |
| e |
0.48795756 |
| q (au) |
1.762569 |
| a (au) |
3.442232 |
| i (deg) |
22.671799 |
| Ω (om, deg) |
203.270091 |
| ω (w, deg) |
199.435229 |
| M (ma, deg) |
107.668137 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.900 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.900 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2021-09-02 |
2022-03-01 |
+12.0411 |
-3.322 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
16:33:36.66 |
-09:27:30.1 |
HIP 81084 |
5.80 |
| 2026-02-03 12:00 |
16:33:54.60 |
-09:26:32.3 |
HIP 81084 |
7.36 |
| 2026-02-04 00:00 |
16:34:12.41 |
-09:25:33.6 |
HIP 81084 |
10.75 |
| 2026-02-04 12:00 |
16:34:30.10 |
-09:24:34.0 |
HIP 81084 |
14.72 |
| 2026-02-05 00:00 |
16:34:47.66 |
-09:23:33.5 |
HIP 81217 |
18.59 |
| 2026-02-05 12:00 |
16:35:05.09 |
-09:22:32.1 |
HIP 81217 |
18.18 |
| 2026-02-06 00:00 |
16:35:22.40 |
-09:21:29.9 |
HIP 81217 |
18.84 |
| 2026-02-06 12:00 |
16:35:39.57 |
-09:20:26.7 |
HIP 81217 |
20.46 |
| 2026-02-07 00:00 |
16:35:56.62 |
-09:19:22.7 |
HIP 81217 |
22.80 |
| 2026-02-07 12:00 |
16:36:13.53 |
-09:18:17.7 |
HIP 81217 |
25.67 |
| 2026-02-08 00:00 |
16:36:30.30 |
-09:17:11.9 |
HIP 81360 |
24.83 |
| 2026-02-08 12:00 |
16:36:46.94 |
-09:16:05.2 |
HIP 81360 |
23.00 |
| 2026-02-09 00:00 |
16:37:03.45 |
-09:14:57.5 |
HIP 81360 |
21.84 |
| 2026-02-09 12:00 |
16:37:19.82 |
-09:13:49.0 |
HIP 81360 |
21.44 |
| 2026-02-10 00:00 |
16:37:36.05 |
-09:12:39.6 |
HIP 81360 |
21.82 |
| 2026-02-10 12:00 |
16:37:52.14 |
-09:11:29.3 |
HIP 81360 |
22.94 |
| 2026-02-11 00:00 |
16:38:08.09 |
-09:10:18.1 |
HIP 81360 |
24.67 |
| 2026-02-11 12:00 |
16:38:23.90 |
-09:09:06.1 |
HIP 81360 |
26.89 |
| 2026-02-12 00:00 |
16:38:39.57 |
-09:07:53.1 |
HIP 81580 |
29.32 |
| 2026-02-12 12:00 |
16:38:55.09 |
-09:06:39.2 |
HIP 81580 |
28.73 |
| 2026-02-13 00:00 |
16:39:10.47 |
-09:05:24.5 |
HIP 81580 |
28.73 |
| 2026-02-13 12:00 |
16:39:25.70 |
-09:04:08.9 |
HIP 81499 |
28.61 |
| 2026-02-14 00:00 |
16:39:40.78 |
-09:02:52.4 |
HIP 81499 |
28.90 |
| 2026-02-14 12:00 |
16:39:55.72 |
-09:01:35.0 |
HIP 81499 |
29.68 |
| 2026-02-15 00:00 |
16:40:10.50 |
-09:00:16.7 |
HIP 81499 |
30.90 |
| 2026-02-15 12:00 |
16:40:25.14 |
-08:58:57.5 |
HIP 81499 |
32.50 |
| 2026-02-16 00:00 |
16:40:39.62 |
-08:57:37.5 |
HIP 81499 |
34.42 |
| 2026-02-16 12:00 |
16:40:53.95 |
-08:56:16.6 |
HIP 81843 |
31.46 |
| 2026-02-17 00:00 |
16:41:08.12 |
-08:54:54.8 |
HIP 81843 |
28.04 |
| 2026-02-17 12:00 |
16:41:22.14 |
-08:53:32.1 |
HIP 81843 |
24.75 |
| 2026-02-18 00:00 |
16:41:36.01 |
-08:52:08.5 |
HIP 81843 |
21.64 |
| 2026-02-18 12:00 |
16:41:49.71 |
-08:50:44.1 |
HIP 81843 |
18.79 |
| 2026-02-19 00:00 |
16:42:03.26 |
-08:49:18.8 |
HIP 81843 |
16.30 |
| 2026-02-19 12:00 |
16:42:16.65 |
-08:47:52.7 |
HIP 81843 |
14.36 |
| 2026-02-20 00:00 |
16:42:29.87 |
-08:46:25.7 |
HIP 81865 |
11.22 |
| 2026-02-20 12:00 |
16:42:42.94 |
-08:44:57.8 |
HIP 81865 |
7.96 |
| 2026-02-21 00:00 |
16:42:55.84 |
-08:43:29.1 |
HIP 81865 |
5.14 |
| 2026-02-21 12:00 |
16:43:08.58 |
-08:41:59.5 |
HIP 81865 |
3.79 |
| 2026-02-22 00:00 |
16:43:21.15 |
-08:40:29.1 |
HIP 81865 |
5.16 |
| 2026-02-22 12:00 |
16:43:33.56 |
-08:38:57.8 |
HIP 81865 |
7.91 |
| 2026-02-23 00:00 |
16:43:45.80 |
-08:37:25.6 |
HIP 81865 |
11.02 |
| 2026-02-23 12:00 |
16:43:57.87 |
-08:35:52.7 |
HIP 81865 |
14.24 |
| 2026-02-24 00:00 |
16:44:09.78 |
-08:34:18.9 |
HIP 81865 |
17.49 |