| Parameter |
Value |
| Designation |
489P/Denning |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2007-04-20T21:15:31.694400Z |
| Orbit solution date (soln_date, UTC) |
2024-10-11T13:45:58Z |
| Obs used |
302 |
| NEO |
- |
| M1 |
7.600 |
| K1 |
49.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2007-04-17T03:02:00.096000Z |
| Discovery magnitude (MPC) |
18.70 |
| Discovery observatory (MPC) |
704 · Lincoln Laboratory ETS, New Mexico |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2002-08-18.0000000 |
| e |
0.64560760 |
| q (au) |
1.574689 |
| a (au) |
4.443348 |
| i (deg) |
4.007070 |
| Ω (om, deg) |
22.578905 |
| ω (w, deg) |
107.960844 |
| M (ma, deg) |
180.384811 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.591 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.591 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
13:36:03.29 |
-11:59:12.6 |
HIP 66453 |
28.23 |
| 2026-07-29 12:00 |
13:36:36.86 |
-12:02:32.6 |
HIP 66453 |
20.50 |
| 2026-07-30 00:00 |
13:37:10.52 |
-12:05:52.7 |
HIP 66453 |
14.15 |
| 2026-07-30 12:00 |
13:37:44.28 |
-12:09:13.0 |
HIP 66453 |
11.75 |
| 2026-07-31 00:00 |
13:38:18.12 |
-12:12:33.5 |
HIP 66453 |
15.32 |
| 2026-07-31 12:00 |
13:38:52.06 |
-12:15:54.1 |
HIP 66617 |
12.14 |
| 2026-08-01 00:00 |
13:39:26.08 |
-12:19:14.8 |
HIP 66617 |
13.88 |
| 2026-08-01 12:00 |
13:40:00.19 |
-12:22:35.7 |
HIP 66617 |
19.97 |
| 2026-08-02 00:00 |
13:40:34.38 |
-12:25:56.7 |
HIP 66758 |
21.92 |
| 2026-08-02 12:00 |
13:41:08.67 |
-12:29:17.8 |
HIP 66758 |
17.81 |
| 2026-08-03 00:00 |
13:41:43.04 |
-12:32:39.1 |
HIP 66758 |
17.80 |
| 2026-08-03 12:00 |
13:42:17.49 |
-12:36:00.4 |
HIP 66758 |
21.91 |
| 2026-08-04 00:00 |
13:42:52.03 |
-12:39:21.9 |
HIP 66844 |
25.96 |
| 2026-08-04 12:00 |
13:43:26.65 |
-12:42:43.4 |
HIP 66844 |
28.82 |
| 2026-08-05 00:00 |
13:44:01.36 |
-12:46:05.1 |
HIP 67163 |
29.08 |
| 2026-08-05 12:00 |
13:44:36.15 |
-12:49:26.8 |
HIP 67163 |
19.96 |
| 2026-08-06 00:00 |
13:45:11.02 |
-12:52:48.6 |
HIP 67163 |
10.85 |
| 2026-08-06 12:00 |
13:45:45.97 |
-12:56:10.5 |
HIP 67163 |
2.02 |
| 2026-08-07 00:00 |
13:46:21.01 |
-12:59:32.5 |
HIP 67163 |
7.64 |
| 2026-08-07 12:00 |
13:46:56.12 |
-13:02:54.5 |
HIP 67254 |
4.34 |
| 2026-08-08 00:00 |
13:47:31.32 |
-13:06:16.6 |
HIP 67254 |
6.53 |
| 2026-08-08 12:00 |
13:48:06.59 |
-13:09:38.7 |
HIP 67254 |
15.38 |
| 2026-08-09 00:00 |
13:48:41.94 |
-13:13:00.9 |
HIP 67254 |
24.52 |
| 2026-08-09 12:00 |
13:49:17.37 |
-13:16:23.2 |
HIP 67541 |
18.29 |
| 2026-08-10 00:00 |
13:49:52.88 |
-13:19:45.5 |
HIP 67541 |
14.80 |
| 2026-08-10 12:00 |
13:50:28.47 |
-13:23:07.8 |
HIP 67541 |
16.62 |
| 2026-08-11 00:00 |
13:51:04.13 |
-13:26:30.1 |
HIP 67600 |
14.25 |
| 2026-08-11 12:00 |
13:51:39.87 |
-13:29:52.5 |
HIP 67600 |
13.65 |
| 2026-08-12 00:00 |
13:52:15.69 |
-13:33:14.8 |
HIP 67600 |
18.54 |
| 2026-08-12 12:00 |
13:52:51.57 |
-13:36:37.2 |
HIP 67600 |
26.00 |
| 2026-08-13 00:00 |
13:53:27.54 |
-13:39:59.6 |
HIP 68016 |
32.85 |
| 2026-08-13 12:00 |
13:54:03.57 |
-13:43:22.0 |
HIP 68016 |
23.82 |
| 2026-08-14 00:00 |
13:54:39.68 |
-13:46:44.4 |
HIP 68016 |
15.21 |
| 2026-08-14 12:00 |
13:55:15.86 |
-13:50:06.7 |
HIP 68016 |
8.45 |
| 2026-08-15 00:00 |
13:55:52.11 |
-13:53:29.0 |
HIP 68016 |
9.42 |
| 2026-08-15 12:00 |
13:56:28.43 |
-13:56:51.3 |
HIP 68016 |
16.86 |
| 2026-08-16 00:00 |
13:57:04.82 |
-14:00:13.5 |
HIP 68267 |
21.81 |
| 2026-08-16 12:00 |
13:57:41.27 |
-14:03:35.7 |
HIP 68267 |
12.35 |
| 2026-08-17 00:00 |
13:58:17.80 |
-14:06:57.9 |
HIP 68267 |
2.94 |
| 2026-08-17 12:00 |
13:58:54.39 |
-14:10:19.9 |
HIP 68267 |
6.67 |
| 2026-08-18 00:00 |
13:59:31.04 |
-14:13:41.9 |
HIP 68291 |
14.73 |
| 2026-08-18 12:00 |
14:00:07.76 |
-14:17:03.9 |
HIP 68291 |
20.89 |
| 2026-08-19 00:00 |
14:00:44.55 |
-14:20:25.7 |
HIP 68604 |
26.58 |