| Parameter |
Value |
| Designation |
9P/Tempel 1 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2016-08-02T13:41:50.605440Z |
| Orbit solution date (soln_date, UTC) |
2025-12-29T09:30:51Z |
| Obs used |
3283 |
| NEO |
- |
| M1 |
12.900 |
| K1 |
9.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2016-03-23.0000000 |
| e |
0.50970283 |
| q (au) |
1.542540 |
| a (au) |
3.146134 |
| i (deg) |
10.473428 |
| Ω (om, deg) |
68.753575 |
| ω (w, deg) |
179.197275 |
| M (ma, deg) |
336.585444 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.220 + 2.445\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.220 |
| n |
2.445 |
| gf |
0.827 |
| gb |
-0.761 |
| k |
0.841 |
| δ90 |
2.893 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-25 00:00 |
08:59:30.51 |
+24:34:24.9 |
HIP 44222 |
13.41 |
| 2026-09-25 12:00 |
09:00:02.44 |
+24:33:12.6 |
HIP 44222 |
6.33 |
| 2026-09-26 00:00 |
09:00:34.29 |
+24:32:00.7 |
HIP 44222 |
2.93 |
| 2026-09-26 12:00 |
09:01:06.06 |
+24:30:49.2 |
HIP 44222 |
9.20 |
| 2026-09-27 00:00 |
09:01:37.75 |
+24:29:38.0 |
HIP 44405 |
15.33 |
| 2026-09-27 12:00 |
09:02:09.36 |
+24:28:27.2 |
HIP 44405 |
8.05 |
| 2026-09-28 00:00 |
09:02:40.89 |
+24:27:16.7 |
HIP 44405 |
0.78 |
| 2026-09-28 12:00 |
09:03:12.33 |
+24:26:06.6 |
HIP 44405 |
6.48 |
| 2026-09-29 00:00 |
09:03:43.69 |
+24:24:56.9 |
HIP 44405 |
13.71 |
| 2026-09-29 12:00 |
09:04:14.97 |
+24:23:47.6 |
HIP 44571 |
15.02 |
| 2026-09-30 00:00 |
09:04:46.16 |
+24:22:38.7 |
HIP 44571 |
13.72 |
| 2026-09-30 12:00 |
09:05:17.27 |
+24:21:30.3 |
HIP 44571 |
15.93 |
| 2026-10-01 00:00 |
09:05:48.29 |
+24:20:22.2 |
HIP 44718 |
12.89 |
| 2026-10-01 12:00 |
09:06:19.22 |
+24:19:14.6 |
HIP 44718 |
6.86 |
| 2026-10-02 00:00 |
09:06:50.07 |
+24:18:07.4 |
HIP 44718 |
5.44 |
| 2026-10-02 12:00 |
09:07:20.82 |
+24:17:00.7 |
HIP 44718 |
10.63 |
| 2026-10-03 00:00 |
09:07:51.48 |
+24:15:54.4 |
HIP 44718 |
17.21 |
| 2026-10-03 12:00 |
09:08:22.05 |
+24:14:48.6 |
HIP 44718 |
24.05 |
| 2026-10-04 00:00 |
09:08:52.53 |
+24:13:43.3 |
HIP 44718 |
30.96 |
| 2026-10-04 12:00 |
09:09:22.92 |
+24:12:38.4 |
HIP 44718 |
37.90 |
| 2026-10-05 00:00 |
09:09:53.21 |
+24:11:34.1 |
HIP 44941 |
42.22 |
| 2026-10-05 12:00 |
09:10:23.40 |
+24:10:30.3 |
HIP 44941 |
43.20 |
| 2026-10-06 00:00 |
09:10:53.49 |
+24:09:27.0 |
HIP 45268 |
37.29 |
| 2026-10-06 12:00 |
09:11:23.49 |
+24:08:24.2 |
HIP 45268 |
30.95 |
| 2026-10-07 00:00 |
09:11:53.39 |
+24:07:22.0 |
HIP 45268 |
24.93 |
| 2026-10-07 12:00 |
09:12:23.19 |
+24:06:20.4 |
HIP 45268 |
19.52 |
| 2026-10-08 00:00 |
09:12:52.88 |
+24:05:19.3 |
HIP 45268 |
15.32 |
| 2026-10-08 12:00 |
09:13:22.47 |
+24:04:18.7 |
HIP 45268 |
13.50 |
| 2026-10-09 00:00 |
09:13:51.96 |
+24:03:18.8 |
HIP 45268 |
14.92 |
| 2026-10-09 12:00 |
09:14:21.34 |
+24:02:19.5 |
HIP 45268 |
18.82 |
| 2026-10-10 00:00 |
09:14:50.62 |
+24:01:20.7 |
HIP 45423 |
16.85 |
| 2026-10-10 12:00 |
09:15:19.79 |
+24:00:22.6 |
HIP 45423 |
14.19 |
| 2026-10-11 00:00 |
09:15:48.85 |
+23:59:25.1 |
HIP 45423 |
14.49 |
| 2026-10-11 12:00 |
09:16:17.80 |
+23:58:28.2 |
HIP 45423 |
17.55 |
| 2026-10-12 00:00 |
09:16:46.63 |
+23:57:32.0 |
HIP 45574 |
19.82 |
| 2026-10-12 12:00 |
09:17:15.36 |
+23:56:36.5 |
HIP 45574 |
17.46 |
| 2026-10-13 00:00 |
09:17:43.98 |
+23:55:41.6 |
HIP 45574 |
17.46 |
| 2026-10-13 12:00 |
09:18:12.47 |
+23:54:47.4 |
HIP 45574 |
19.80 |
| 2026-10-14 00:00 |
09:18:40.86 |
+23:53:53.8 |
HIP 45574 |
23.78 |
| 2026-10-14 12:00 |
09:19:09.13 |
+23:53:01.0 |
HIP 45574 |
28.70 |
| 2026-10-15 00:00 |
09:19:37.28 |
+23:52:08.9 |
HIP 45728 |
32.23 |
| 2026-10-15 12:00 |
09:20:05.31 |
+23:51:17.5 |
HIP 45756 |
33.90 |
| 2026-10-16 00:00 |
09:20:33.22 |
+23:50:26.8 |
HIP 45756 |
35.97 |