| 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) |
| 2026-06-01 00:00 |
16:22:46.52 |
-01:35:31.7 |
HIP 80120 |
28.06 |
| 2026-06-01 12:00 |
16:22:26.80 |
-01:34:03.9 |
HIP 80120 |
25.30 |
| 2026-06-02 00:00 |
16:22:07.09 |
-01:32:37.4 |
HIP 80120 |
23.34 |
| 2026-06-02 12:00 |
16:21:47.39 |
-01:31:12.3 |
HIP 80120 |
22.39 |
| 2026-06-03 00:00 |
16:21:27.71 |
-01:29:48.5 |
HIP 80069 |
20.92 |
| 2026-06-03 12:00 |
16:21:08.06 |
-01:28:26.1 |
HIP 80069 |
19.35 |
| 2026-06-04 00:00 |
16:20:48.43 |
-01:27:05.1 |
HIP 80069 |
19.04 |
| 2026-06-04 12:00 |
16:20:28.83 |
-01:25:45.4 |
HIP 80069 |
20.04 |
| 2026-06-05 00:00 |
16:20:09.26 |
-01:24:27.1 |
HIP 80069 |
22.16 |
| 2026-06-05 12:00 |
16:19:49.72 |
-01:23:10.2 |
HIP 79919 |
23.49 |
| 2026-06-06 00:00 |
16:19:30.22 |
-01:21:54.8 |
HIP 79919 |
19.42 |
| 2026-06-06 12:00 |
16:19:10.76 |
-01:20:40.7 |
HIP 79919 |
15.94 |
| 2026-06-07 00:00 |
16:18:51.34 |
-01:19:28.0 |
HIP 79919 |
13.49 |
| 2026-06-07 12:00 |
16:18:31.97 |
-01:18:16.8 |
HIP 79919 |
12.66 |
| 2026-06-08 00:00 |
16:18:12.65 |
-01:17:07.0 |
HIP 79919 |
13.74 |
| 2026-06-08 12:00 |
16:17:53.38 |
-01:15:58.6 |
HIP 79919 |
16.33 |
| 2026-06-09 00:00 |
16:17:34.17 |
-01:14:51.7 |
HIP 79919 |
19.84 |
| 2026-06-09 12:00 |
16:17:15.02 |
-01:13:46.3 |
HIP 79717 |
23.17 |
| 2026-06-10 00:00 |
16:16:55.93 |
-01:12:42.3 |
HIP 79717 |
19.29 |
| 2026-06-10 12:00 |
16:16:36.90 |
-01:11:39.7 |
HIP 79717 |
16.02 |
| 2026-06-11 00:00 |
16:16:17.94 |
-01:10:38.7 |
HIP 79717 |
13.75 |
| 2026-06-11 12:00 |
16:15:59.05 |
-01:09:39.1 |
HIP 79717 |
13.00 |
| 2026-06-12 00:00 |
16:15:40.24 |
-01:08:41.0 |
HIP 79717 |
14.00 |
| 2026-06-12 12:00 |
16:15:21.50 |
-01:07:44.4 |
HIP 79717 |
16.40 |
| 2026-06-13 00:00 |
16:15:02.84 |
-01:06:49.2 |
HIP 79717 |
19.68 |
| 2026-06-13 12:00 |
16:14:44.27 |
-01:05:55.6 |
HIP 79717 |
23.46 |
| 2026-06-14 00:00 |
16:14:25.78 |
-01:05:03.5 |
HIP 79486 |
26.05 |
| 2026-06-14 12:00 |
16:14:07.39 |
-01:04:12.9 |
HIP 79486 |
23.86 |
| 2026-06-15 00:00 |
16:13:49.08 |
-01:03:23.8 |
HIP 79486 |
22.43 |
| 2026-06-15 12:00 |
16:13:30.88 |
-01:02:36.2 |
HIP 79486 |
21.89 |
| 2026-06-16 00:00 |
16:13:12.77 |
-01:01:50.1 |
HIP 79486 |
22.28 |
| 2026-06-16 12:00 |
16:12:54.76 |
-01:01:05.6 |
HIP 79348 |
22.22 |
| 2026-06-17 00:00 |
16:12:36.86 |
-01:00:22.5 |
HIP 79348 |
18.06 |
| 2026-06-17 12:00 |
16:12:19.06 |
-00:59:41.0 |
HIP 79348 |
14.15 |
| 2026-06-18 00:00 |
16:12:01.38 |
-00:59:01.0 |
HIP 79348 |
10.76 |
| 2026-06-18 12:00 |
16:11:43.81 |
-00:58:22.5 |
HIP 79348 |
8.48 |
| 2026-06-19 00:00 |
16:11:26.35 |
-00:57:45.5 |
HIP 79348 |
8.22 |
| 2026-06-19 12:00 |
16:11:09.01 |
-00:57:10.0 |
HIP 79307 |
9.67 |
| 2026-06-20 00:00 |
16:10:51.80 |
-00:56:36.0 |
HIP 79307 |
11.00 |
| 2026-06-20 12:00 |
16:10:34.70 |
-00:56:03.6 |
HIP 79307 |
13.61 |
| 2026-06-21 00:00 |
16:10:17.74 |
-00:55:32.6 |
HIP 79307 |
16.89 |
| 2026-06-21 12:00 |
16:10:00.90 |
-00:55:03.2 |
HIP 79170 |
19.96 |
| 2026-06-22 00:00 |
16:09:44.19 |
-00:54:35.3 |
HIP 79170 |
18.34 |