| 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 |
-0.998 |
| 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) |
| 2026-03-26 00:00 |
13:09:53.86 |
-06:03:46.1 |
HIP 64147 |
16.54 |
| 2026-03-26 12:00 |
13:09:28.19 |
-06:03:00.4 |
HIP 64147 |
10.20 |
| 2026-03-27 00:00 |
13:09:02.43 |
-06:02:13.9 |
HIP 64147 |
4.10 |
| 2026-03-27 12:00 |
13:08:36.58 |
-06:01:26.7 |
HIP 64147 |
3.60 |
| 2026-03-28 00:00 |
13:08:10.66 |
-06:00:38.9 |
HIP 64147 |
9.65 |
| 2026-03-28 12:00 |
13:07:44.69 |
-05:59:50.5 |
HIP 64023 |
9.73 |
| 2026-03-29 00:00 |
13:07:18.66 |
-05:59:01.5 |
HIP 64023 |
6.17 |
| 2026-03-29 12:00 |
13:06:52.60 |
-05:58:12.0 |
HIP 64023 |
8.17 |
| 2026-03-30 00:00 |
13:06:26.52 |
-05:57:22.1 |
HIP 64023 |
13.45 |
| 2026-03-30 12:00 |
13:06:00.43 |
-05:56:31.9 |
HIP 63871 |
18.92 |
| 2026-03-31 00:00 |
13:05:34.33 |
-05:55:41.3 |
HIP 63871 |
17.84 |
| 2026-03-31 12:00 |
13:05:08.24 |
-05:54:50.4 |
HIP 63871 |
19.09 |
| 2026-04-01 00:00 |
13:04:42.18 |
-05:53:59.2 |
HIP 63871 |
22.28 |
| 2026-04-01 12:00 |
13:04:16.15 |
-05:53:07.9 |
HIP 63674 |
20.48 |
| 2026-04-02 00:00 |
13:03:50.16 |
-05:52:16.5 |
HIP 63674 |
14.19 |
| 2026-04-02 12:00 |
13:03:24.22 |
-05:51:25.0 |
HIP 63674 |
8.27 |
| 2026-04-03 00:00 |
13:02:58.35 |
-05:50:33.4 |
HIP 63674 |
4.49 |
| 2026-04-03 12:00 |
13:02:32.56 |
-05:49:41.8 |
HIP 63674 |
7.48 |
| 2026-04-04 00:00 |
13:02:06.85 |
-05:48:50.4 |
HIP 63674 |
13.23 |
| 2026-04-04 12:00 |
13:01:41.24 |
-05:47:59.0 |
HIP 63674 |
19.40 |
| 2026-04-05 00:00 |
13:01:15.73 |
-05:47:07.8 |
HIP 63523 |
25.33 |
| 2026-04-05 12:00 |
13:00:50.34 |
-05:46:16.8 |
HIP 63523 |
24.30 |
| 2026-04-06 00:00 |
13:00:25.07 |
-05:45:26.0 |
HIP 63523 |
24.92 |
| 2026-04-06 12:00 |
12:59:59.95 |
-05:44:35.6 |
HIP 63363 |
25.61 |
| 2026-04-07 00:00 |
12:59:34.96 |
-05:43:45.5 |
HIP 63363 |
23.36 |
| 2026-04-07 12:00 |
12:59:10.14 |
-05:42:55.8 |
HIP 63363 |
22.66 |
| 2026-04-08 00:00 |
12:58:45.48 |
-05:42:06.5 |
HIP 63363 |
23.63 |
| 2026-04-08 12:00 |
12:58:20.99 |
-05:41:17.8 |
HIP 63266 |
23.86 |
| 2026-04-09 00:00 |
12:57:56.69 |
-05:40:29.5 |
HIP 63266 |
21.93 |
| 2026-04-09 12:00 |
12:57:32.58 |
-05:39:41.9 |
HIP 63266 |
21.60 |
| 2026-04-10 00:00 |
12:57:08.67 |
-05:38:54.9 |
HIP 63266 |
22.91 |
| 2026-04-10 12:00 |
12:56:44.98 |
-05:38:08.6 |
HIP 63266 |
25.57 |
| 2026-04-11 00:00 |
12:56:21.50 |
-05:37:23.0 |
HIP 63054 |
20.21 |
| 2026-04-11 12:00 |
12:55:58.25 |
-05:36:38.1 |
HIP 63054 |
14.95 |
| 2026-04-12 00:00 |
12:55:35.23 |
-05:35:54.1 |
HIP 63054 |
10.38 |
| 2026-04-12 12:00 |
12:55:12.46 |
-05:35:10.9 |
HIP 63054 |
7.66 |
| 2026-04-13 00:00 |
12:54:49.95 |
-05:34:28.6 |
HIP 63054 |
8.63 |
| 2026-04-13 12:00 |
12:54:27.69 |
-05:33:47.3 |
HIP 63054 |
12.37 |
| 2026-04-14 00:00 |
12:54:05.70 |
-05:33:06.9 |
HIP 63054 |
17.08 |
| 2026-04-14 12:00 |
12:53:43.99 |
-05:32:27.6 |
HIP 63054 |
22.10 |
| 2026-04-15 00:00 |
12:53:22.56 |
-05:31:49.3 |
HIP 63054 |
27.22 |
| 2026-04-15 12:00 |
12:53:01.42 |
-05:31:12.1 |
HIP 62898 |
31.60 |
| 2026-04-16 00:00 |
12:52:40.57 |
-05:30:36.0 |
HIP 62898 |
32.45 |