| Parameter |
Value |
| Designation |
P/2003 T12 (SOHO) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-01-26T10:43:04.114560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:34Z |
| Obs used |
491 |
| NEO |
Yes |
| M1 |
19.600 |
| K1 |
21.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-05-25.0000000 |
| e |
0.77616614 |
| q (au) |
0.574806 |
| a (au) |
2.568002 |
| i (deg) |
11.475154 |
| Ω (om, deg) |
176.465715 |
| ω (w, deg) |
217.668833 |
| M (ma, deg) |
28.633414 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.124 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.124 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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 |
| 2016-02-21 |
2016-05-05 |
+25.0682 |
+4.478 |
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 |
13:29:54.55 |
-00:59:10.9 |
HIP 65840 |
24.70 |
| 2026-06-01 12:00 |
13:29:41.67 |
-00:58:24.5 |
HIP 65708 |
22.28 |
| 2026-06-02 00:00 |
13:29:29.00 |
-00:57:39.7 |
HIP 65708 |
19.06 |
| 2026-06-02 12:00 |
13:29:16.55 |
-00:56:56.5 |
HIP 65708 |
15.92 |
| 2026-06-03 00:00 |
13:29:04.31 |
-00:56:14.8 |
HIP 65708 |
12.86 |
| 2026-06-03 12:00 |
13:28:52.29 |
-00:55:34.6 |
HIP 65708 |
9.91 |
| 2026-06-04 00:00 |
13:28:40.48 |
-00:54:55.9 |
HIP 65708 |
7.14 |
| 2026-06-04 12:00 |
13:28:28.89 |
-00:54:18.7 |
HIP 65708 |
4.73 |
| 2026-06-05 00:00 |
13:28:17.52 |
-00:53:43.1 |
HIP 65708 |
3.38 |
| 2026-06-05 12:00 |
13:28:06.36 |
-00:53:09.0 |
HIP 65708 |
4.14 |
| 2026-06-06 00:00 |
13:27:55.42 |
-00:52:36.4 |
HIP 65708 |
6.21 |
| 2026-06-06 12:00 |
13:27:44.70 |
-00:52:05.3 |
HIP 65708 |
8.65 |
| 2026-06-07 00:00 |
13:27:34.20 |
-00:51:35.8 |
HIP 65708 |
11.16 |
| 2026-06-07 12:00 |
13:27:23.91 |
-00:51:07.7 |
HIP 65708 |
13.69 |
| 2026-06-08 00:00 |
13:27:13.85 |
-00:50:41.2 |
HIP 65708 |
16.18 |
| 2026-06-08 12:00 |
13:27:04.00 |
-00:50:16.1 |
HIP 65708 |
18.64 |
| 2026-06-09 00:00 |
13:26:54.38 |
-00:49:52.6 |
HIP 65708 |
21.05 |
| 2026-06-09 12:00 |
13:26:44.98 |
-00:49:30.5 |
HIP 65708 |
23.41 |
| 2026-06-10 00:00 |
13:26:35.79 |
-00:49:10.0 |
HIP 65545 |
23.19 |
| 2026-06-10 12:00 |
13:26:26.83 |
-00:48:50.9 |
HIP 65545 |
23.02 |
| 2026-06-11 00:00 |
13:26:18.09 |
-00:48:33.3 |
HIP 65514 |
22.87 |
| 2026-06-11 12:00 |
13:26:09.57 |
-00:48:17.2 |
HIP 65514 |
21.93 |
| 2026-06-12 00:00 |
13:26:01.27 |
-00:48:02.6 |
HIP 65514 |
21.20 |
| 2026-06-12 12:00 |
13:25:53.20 |
-00:47:49.5 |
HIP 65514 |
20.69 |
| 2026-06-13 00:00 |
13:25:45.35 |
-00:47:37.8 |
HIP 65514 |
20.39 |
| 2026-06-13 12:00 |
13:25:37.72 |
-00:47:27.6 |
HIP 65514 |
20.30 |
| 2026-06-14 00:00 |
13:25:30.31 |
-00:47:18.9 |
HIP 65514 |
20.41 |
| 2026-06-14 12:00 |
13:25:23.12 |
-00:47:11.6 |
HIP 65514 |
20.69 |
| 2026-06-15 00:00 |
13:25:16.16 |
-00:47:05.7 |
HIP 65514 |
21.12 |
| 2026-06-15 12:00 |
13:25:09.42 |
-00:47:01.4 |
HIP 65514 |
21.68 |
| 2026-06-16 00:00 |
13:25:02.90 |
-00:46:58.4 |
HIP 65360 |
20.29 |
| 2026-06-16 12:00 |
13:24:56.60 |
-00:46:56.9 |
HIP 65360 |
18.74 |
| 2026-06-17 00:00 |
13:24:50.53 |
-00:46:56.8 |
HIP 65360 |
17.26 |
| 2026-06-17 12:00 |
13:24:44.68 |
-00:46:58.1 |
HIP 65360 |
15.84 |
| 2026-06-18 00:00 |
13:24:39.05 |
-00:47:00.9 |
HIP 65360 |
14.49 |
| 2026-06-18 12:00 |
13:24:33.64 |
-00:47:05.0 |
HIP 65360 |
13.21 |
| 2026-06-19 00:00 |
13:24:28.45 |
-00:47:10.5 |
HIP 65360 |
12.01 |
| 2026-06-19 12:00 |
13:24:23.48 |
-00:47:17.5 |
HIP 65360 |
10.89 |
| 2026-06-20 00:00 |
13:24:18.73 |
-00:47:25.8 |
HIP 65360 |
9.86 |
| 2026-06-20 12:00 |
13:24:14.20 |
-00:47:35.4 |
HIP 65360 |
8.93 |
| 2026-06-21 00:00 |
13:24:09.89 |
-00:47:46.5 |
HIP 65360 |
8.12 |
| 2026-06-21 12:00 |
13:24:05.80 |
-00:47:58.9 |
HIP 65360 |
7.44 |
| 2026-06-22 00:00 |
13:24:01.92 |
-00:48:12.6 |
HIP 65360 |
6.90 |