| 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) |
| 2026-05-12 00:00 |
01:43:16.62 |
+13:26:18.7 |
HIP 8041 |
29.03 |
| 2026-05-12 12:00 |
01:43:40.60 |
+13:28:36.8 |
HIP 8041 |
31.98 |
| 2026-05-13 00:00 |
01:44:04.56 |
+13:30:54.7 |
HIP 8126 |
32.87 |
| 2026-05-13 12:00 |
01:44:28.48 |
+13:33:12.3 |
HIP 8126 |
30.20 |
| 2026-05-14 00:00 |
01:44:52.37 |
+13:35:29.6 |
HIP 8126 |
28.68 |
| 2026-05-14 12:00 |
01:45:16.22 |
+13:37:46.7 |
HIP 8126 |
28.46 |
| 2026-05-15 00:00 |
01:45:40.04 |
+13:40:03.6 |
HIP 8126 |
29.58 |
| 2026-05-15 12:00 |
01:46:03.82 |
+13:42:20.2 |
HIP 8126 |
31.89 |
| 2026-05-16 00:00 |
01:46:27.57 |
+13:44:36.5 |
HIP 8126 |
35.16 |
| 2026-05-16 12:00 |
01:46:51.27 |
+13:46:52.5 |
HIP 8426 |
31.09 |
| 2026-05-17 00:00 |
01:47:14.94 |
+13:49:08.2 |
HIP 8426 |
25.06 |
| 2026-05-17 12:00 |
01:47:38.57 |
+13:51:23.7 |
HIP 8426 |
19.14 |
| 2026-05-18 00:00 |
01:48:02.16 |
+13:53:38.9 |
HIP 8426 |
13.44 |
| 2026-05-18 12:00 |
01:48:25.71 |
+13:55:53.8 |
HIP 8426 |
8.42 |
| 2026-05-19 00:00 |
01:48:49.22 |
+13:58:08.4 |
HIP 8426 |
6.05 |
| 2026-05-19 12:00 |
01:49:12.69 |
+14:00:22.7 |
HIP 8426 |
8.79 |
| 2026-05-20 00:00 |
01:49:36.11 |
+14:02:36.7 |
HIP 8532 |
12.52 |
| 2026-05-20 12:00 |
01:49:59.49 |
+14:04:50.4 |
HIP 8532 |
8.74 |
| 2026-05-21 00:00 |
01:50:22.83 |
+14:07:03.8 |
HIP 8532 |
8.37 |
| 2026-05-21 12:00 |
01:50:46.12 |
+14:09:16.8 |
HIP 8532 |
11.72 |
| 2026-05-22 00:00 |
01:51:09.36 |
+14:11:29.6 |
HIP 8532 |
16.67 |
| 2026-05-22 12:00 |
01:51:32.56 |
+14:13:42.0 |
HIP 8774 |
19.27 |
| 2026-05-23 00:00 |
01:51:55.71 |
+14:15:54.1 |
HIP 8774 |
14.40 |
| 2026-05-23 12:00 |
01:52:18.81 |
+14:18:05.9 |
HIP 8774 |
10.80 |
| 2026-05-24 00:00 |
01:52:41.87 |
+14:20:17.4 |
HIP 8774 |
9.89 |
| 2026-05-24 12:00 |
01:53:04.87 |
+14:22:28.6 |
HIP 8774 |
12.29 |
| 2026-05-25 00:00 |
01:53:27.83 |
+14:24:39.4 |
HIP 8774 |
16.60 |
| 2026-05-25 12:00 |
01:53:50.73 |
+14:26:49.8 |
HIP 8774 |
21.70 |
| 2026-05-26 00:00 |
01:54:13.59 |
+14:29:00.0 |
HIP 8774 |
27.14 |
| 2026-05-26 12:00 |
01:54:36.39 |
+14:31:09.8 |
HIP 8795 |
31.11 |
| 2026-05-27 00:00 |
01:54:59.14 |
+14:33:19.2 |
HIP 8981 |
33.97 |
| 2026-05-27 12:00 |
01:55:21.84 |
+14:35:28.4 |
HIP 8981 |
30.49 |
| 2026-05-28 00:00 |
01:55:44.49 |
+14:37:37.1 |
HIP 8981 |
27.84 |
| 2026-05-28 12:00 |
01:56:07.08 |
+14:39:45.5 |
HIP 8981 |
26.27 |
| 2026-05-29 00:00 |
01:56:29.62 |
+14:41:53.6 |
HIP 8981 |
25.95 |
| 2026-05-29 12:00 |
01:56:52.10 |
+14:44:01.3 |
HIP 9137 |
24.47 |
| 2026-05-30 00:00 |
01:57:14.52 |
+14:46:08.7 |
HIP 9137 |
24.06 |
| 2026-05-30 12:00 |
01:57:36.89 |
+14:48:15.7 |
HIP 9137 |
25.03 |
| 2026-05-31 00:00 |
01:57:59.21 |
+14:50:22.3 |
HIP 9286 |
23.47 |
| 2026-05-31 12:00 |
01:58:21.46 |
+14:52:28.6 |
HIP 9286 |
20.66 |
| 2026-06-01 00:00 |
01:58:43.66 |
+14:54:34.5 |
HIP 9286 |
19.22 |
| 2026-06-01 12:00 |
01:59:05.79 |
+14:56:40.0 |
HIP 9286 |
19.45 |
| 2026-06-02 00:00 |
01:59:27.87 |
+14:58:45.1 |
HIP 9301 |
17.69 |