| Parameter |
Value |
| Designation |
79P/du Toit-Hartley |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2008-05-28T09:52:27.811200Z |
| Orbit solution date (soln_date, UTC) |
2021-05-04T14:20:50Z |
| Obs used |
215 |
| NEO |
Yes |
| M1 |
17.400 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2007-10-18.0000000 |
| e |
0.59408527 |
| q (au) |
1.230504 |
| a (au) |
3.031435 |
| i (deg) |
2.893178 |
| Ω (om, deg) |
307.838646 |
| ω (w, deg) |
253.269688 |
| M (ma, deg) |
318.280693 |
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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
02:28:12.24 |
+18:20:49.0 |
HIP 11532 |
33.16 |
| 2026-09-20 12:00 |
02:27:58.68 |
+18:20:00.5 |
HIP 11532 |
33.21 |
| 2026-09-21 00:00 |
02:27:44.90 |
+18:19:10.7 |
HIP 11532 |
33.58 |
| 2026-09-21 12:00 |
02:27:30.91 |
+18:18:19.8 |
HIP 11532 |
34.30 |
| 2026-09-22 00:00 |
02:27:16.71 |
+18:17:27.6 |
HIP 11532 |
35.35 |
| 2026-09-22 12:00 |
02:27:02.31 |
+18:16:34.2 |
HIP 11532 |
36.72 |
| 2026-09-23 00:00 |
02:26:47.69 |
+18:15:39.6 |
HIP 11532 |
38.38 |
| 2026-09-23 12:00 |
02:26:32.88 |
+18:14:43.8 |
HIP 11384 |
38.92 |
| 2026-09-24 00:00 |
02:26:17.85 |
+18:13:46.8 |
HIP 11384 |
38.36 |
| 2026-09-24 12:00 |
02:26:02.63 |
+18:12:48.5 |
HIP 11158 |
36.14 |
| 2026-09-25 00:00 |
02:25:47.20 |
+18:11:49.1 |
HIP 11158 |
32.36 |
| 2026-09-25 12:00 |
02:25:31.58 |
+18:10:48.4 |
HIP 11158 |
28.53 |
| 2026-09-26 00:00 |
02:25:15.76 |
+18:09:46.5 |
HIP 11158 |
24.66 |
| 2026-09-26 12:00 |
02:24:59.74 |
+18:08:43.5 |
HIP 11158 |
20.74 |
| 2026-09-27 00:00 |
02:24:43.53 |
+18:07:39.2 |
HIP 11158 |
16.79 |
| 2026-09-27 12:00 |
02:24:27.13 |
+18:06:33.7 |
HIP 11158 |
12.82 |
| 2026-09-28 00:00 |
02:24:10.53 |
+18:05:27.0 |
HIP 11158 |
8.87 |
| 2026-09-28 12:00 |
02:23:53.75 |
+18:04:19.1 |
HIP 11158 |
5.13 |
| 2026-09-29 00:00 |
02:23:36.78 |
+18:03:10.0 |
HIP 11158 |
2.88 |
| 2026-09-29 12:00 |
02:23:19.63 |
+18:01:59.7 |
HIP 11158 |
5.09 |
| 2026-09-30 00:00 |
02:23:02.29 |
+18:00:48.2 |
HIP 11158 |
8.97 |
| 2026-09-30 12:00 |
02:22:44.77 |
+17:59:35.6 |
HIP 11158 |
13.15 |
| 2026-10-01 00:00 |
02:22:27.07 |
+17:58:21.7 |
HIP 11158 |
17.46 |
| 2026-10-01 12:00 |
02:22:09.20 |
+17:57:06.7 |
HIP 11158 |
21.84 |
| 2026-10-02 00:00 |
02:21:51.15 |
+17:55:50.5 |
HIP 11112 |
25.77 |
| 2026-10-02 12:00 |
02:21:32.93 |
+17:54:33.1 |
HIP 11112 |
27.83 |
| 2026-10-03 00:00 |
02:21:14.53 |
+17:53:14.6 |
HIP 11112 |
30.46 |
| 2026-10-03 12:00 |
02:20:55.97 |
+17:51:54.9 |
HIP 11112 |
33.52 |
| 2026-10-04 00:00 |
02:20:37.25 |
+17:50:34.0 |
HIP 11112 |
36.95 |
| 2026-10-04 12:00 |
02:20:18.36 |
+17:49:12.0 |
HIP 11112 |
40.65 |
| 2026-10-05 00:00 |
02:19:59.31 |
+17:47:48.8 |
HIP 10666 |
39.15 |
| 2026-10-05 12:00 |
02:19:40.10 |
+17:46:24.5 |
HIP 10666 |
34.59 |
| 2026-10-06 00:00 |
02:19:20.74 |
+17:44:59.1 |
HIP 10666 |
30.05 |
| 2026-10-06 12:00 |
02:19:01.22 |
+17:43:32.5 |
HIP 10666 |
25.58 |
| 2026-10-07 00:00 |
02:18:41.56 |
+17:42:04.8 |
HIP 10666 |
21.26 |
| 2026-10-07 12:00 |
02:18:21.74 |
+17:40:36.1 |
HIP 10666 |
17.23 |
| 2026-10-08 00:00 |
02:18:01.79 |
+17:39:06.2 |
HIP 10666 |
13.78 |
| 2026-10-08 12:00 |
02:17:41.69 |
+17:37:35.2 |
HIP 10666 |
11.51 |
| 2026-10-09 00:00 |
02:17:21.46 |
+17:36:03.2 |
HIP 10666 |
11.22 |
| 2026-10-09 12:00 |
02:17:01.09 |
+17:34:30.1 |
HIP 10666 |
13.08 |
| 2026-10-10 00:00 |
02:16:40.59 |
+17:32:55.9 |
HIP 10648 |
14.99 |
| 2026-10-10 12:00 |
02:16:19.96 |
+17:31:20.7 |
HIP 10648 |
16.17 |
| 2026-10-11 00:00 |
02:15:59.20 |
+17:29:44.5 |
HIP 10648 |
18.77 |