| Parameter |
Value |
| Designation |
46P/Wirtanen |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-12-12T22:20:53.010240Z |
| Orbit solution date (soln_date, UTC) |
2024-02-21T09:51:41Z |
| Obs used |
4224 |
| NEO |
Yes |
| M1 |
16.600 |
| K1 |
4.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-12-13.0000000 |
| e |
0.65875501 |
| q (au) |
1.055355 |
| a (au) |
3.092662 |
| i (deg) |
11.747549 |
| Ω (om, deg) |
82.157634 |
| ω (w, deg) |
356.341072 |
| M (ma, deg) |
0.012474 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.091 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.091 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.838 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
16:51:23.70 |
-18:00:48.5 |
HIP 82393 |
19.23 |
| 2026-03-26 12:00 |
16:51:20.48 |
-18:00:37.1 |
HIP 82393 |
18.59 |
| 2026-03-27 00:00 |
16:51:17.01 |
-18:00:25.3 |
HIP 82393 |
17.91 |
| 2026-03-27 12:00 |
16:51:13.31 |
-18:00:13.2 |
HIP 82393 |
17.20 |
| 2026-03-28 00:00 |
16:51:09.37 |
-18:00:00.7 |
HIP 82393 |
16.46 |
| 2026-03-28 12:00 |
16:51:05.19 |
-17:59:48.0 |
HIP 82393 |
15.70 |
| 2026-03-29 00:00 |
16:51:00.77 |
-17:59:34.9 |
HIP 82393 |
14.92 |
| 2026-03-29 12:00 |
16:50:56.12 |
-17:59:21.6 |
HIP 82393 |
14.14 |
| 2026-03-30 00:00 |
16:50:51.22 |
-17:59:07.9 |
HIP 82393 |
13.37 |
| 2026-03-30 12:00 |
16:50:46.09 |
-17:58:53.9 |
HIP 82393 |
12.63 |
| 2026-03-31 00:00 |
16:50:40.72 |
-17:58:39.6 |
HIP 82393 |
11.94 |
| 2026-03-31 12:00 |
16:50:35.10 |
-17:58:25.0 |
HIP 82393 |
11.32 |
| 2026-04-01 00:00 |
16:50:29.26 |
-17:58:10.1 |
HIP 82393 |
10.82 |
| 2026-04-01 12:00 |
16:50:23.17 |
-17:57:54.9 |
HIP 82393 |
10.47 |
| 2026-04-02 00:00 |
16:50:16.84 |
-17:57:39.4 |
HIP 82393 |
10.32 |
| 2026-04-02 12:00 |
16:50:10.28 |
-17:57:23.6 |
HIP 82393 |
10.39 |
| 2026-04-03 00:00 |
16:50:03.48 |
-17:57:07.4 |
HIP 82393 |
10.71 |
| 2026-04-03 12:00 |
16:49:56.44 |
-17:56:51.0 |
HIP 82393 |
11.28 |
| 2026-04-04 00:00 |
16:49:49.16 |
-17:56:34.3 |
HIP 82393 |
12.09 |
| 2026-04-04 12:00 |
16:49:41.65 |
-17:56:17.3 |
HIP 82393 |
13.11 |
| 2026-04-05 00:00 |
16:49:33.90 |
-17:56:00.0 |
HIP 82393 |
14.33 |
| 2026-04-05 12:00 |
16:49:25.92 |
-17:55:42.4 |
HIP 82393 |
15.72 |
| 2026-04-06 00:00 |
16:49:17.69 |
-17:55:24.5 |
HIP 82393 |
17.25 |
| 2026-04-06 12:00 |
16:49:09.24 |
-17:55:06.3 |
HIP 82393 |
18.91 |
| 2026-04-07 00:00 |
16:49:00.54 |
-17:54:47.8 |
HIP 82393 |
20.68 |
| 2026-04-07 12:00 |
16:48:51.61 |
-17:54:29.0 |
HIP 82393 |
22.56 |
| 2026-04-08 00:00 |
16:48:42.45 |
-17:54:10.0 |
HIP 82393 |
24.53 |
| 2026-04-08 12:00 |
16:48:33.05 |
-17:53:50.6 |
HIP 82393 |
26.58 |
| 2026-04-09 00:00 |
16:48:23.42 |
-17:53:31.0 |
HIP 82393 |
28.72 |
| 2026-04-09 12:00 |
16:48:13.56 |
-17:53:11.1 |
HIP 82120 |
29.42 |
| 2026-04-10 00:00 |
16:48:03.46 |
-17:52:50.9 |
HIP 82120 |
27.31 |
| 2026-04-10 12:00 |
16:47:53.13 |
-17:52:30.4 |
HIP 82120 |
25.22 |
| 2026-04-11 00:00 |
16:47:42.58 |
-17:52:09.6 |
HIP 82120 |
23.15 |
| 2026-04-11 12:00 |
16:47:31.79 |
-17:51:48.6 |
HIP 82120 |
21.16 |
| 2026-04-12 00:00 |
16:47:20.77 |
-17:51:27.3 |
HIP 82120 |
19.27 |
| 2026-04-12 12:00 |
16:47:09.52 |
-17:51:05.7 |
HIP 82120 |
17.54 |
| 2026-04-13 00:00 |
16:46:58.04 |
-17:50:43.9 |
HIP 82120 |
16.07 |
| 2026-04-13 12:00 |
16:46:46.34 |
-17:50:21.7 |
HIP 82120 |
14.95 |
| 2026-04-14 00:00 |
16:46:34.41 |
-17:49:59.4 |
HIP 82120 |
14.29 |
| 2026-04-14 12:00 |
16:46:22.26 |
-17:49:36.7 |
HIP 82120 |
14.20 |
| 2026-04-15 00:00 |
16:46:09.88 |
-17:49:13.8 |
HIP 82120 |
14.72 |
| 2026-04-15 12:00 |
16:45:57.28 |
-17:48:50.6 |
HIP 82120 |
15.81 |
| 2026-04-16 00:00 |
16:45:44.46 |
-17:48:27.2 |
HIP 82120 |
17.40 |