46P/Wirtanen
| 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
$$
M_a = (15.144 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.144 |
| n |
2.000 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
16:37:46.96 |
-17:46:28.4 |
HIP 81393 |
19.70 |
| 2026-02-03 12:00 |
16:38:04.39 |
-17:46:59.6 |
HIP 81393 |
21.74 |
| 2026-02-04 00:00 |
16:38:21.67 |
-17:47:30.4 |
HIP 81393 |
24.31 |
| 2026-02-04 12:00 |
16:38:38.80 |
-17:48:00.7 |
HIP 81474 |
25.33 |
| 2026-02-05 00:00 |
16:38:55.77 |
-17:48:30.4 |
HIP 81474 |
25.54 |
| 2026-02-05 12:00 |
16:39:12.60 |
-17:48:59.7 |
HIP 81474 |
26.39 |
| 2026-02-06 00:00 |
16:39:29.27 |
-17:49:28.4 |
HIP 81474 |
27.78 |
| 2026-02-06 12:00 |
16:39:45.78 |
-17:49:56.7 |
HIP 81695 |
25.95 |
| 2026-02-07 00:00 |
16:40:02.14 |
-17:50:24.4 |
HIP 81695 |
22.46 |
| 2026-02-07 12:00 |
16:40:18.34 |
-17:50:51.6 |
HIP 81695 |
19.16 |
| 2026-02-08 00:00 |
16:40:34.38 |
-17:51:18.3 |
HIP 81724 |
15.81 |
| 2026-02-08 12:00 |
16:40:50.25 |
-17:51:44.5 |
HIP 81724 |
12.74 |
| 2026-02-09 00:00 |
16:41:05.97 |
-17:52:10.3 |
HIP 81724 |
10.21 |
| 2026-02-09 12:00 |
16:41:21.53 |
-17:52:35.5 |
HIP 81724 |
8.62 |
| 2026-02-10 00:00 |
16:41:36.92 |
-17:53:00.2 |
HIP 81724 |
8.49 |
| 2026-02-10 12:00 |
16:41:52.14 |
-17:53:24.4 |
HIP 81724 |
9.83 |
| 2026-02-11 00:00 |
16:42:07.20 |
-17:53:48.2 |
HIP 81724 |
12.12 |
| 2026-02-11 12:00 |
16:42:22.09 |
-17:54:11.4 |
HIP 81724 |
14.91 |
| 2026-02-12 00:00 |
16:42:36.82 |
-17:54:34.2 |
HIP 81724 |
17.93 |
| 2026-02-12 12:00 |
16:42:51.37 |
-17:54:56.4 |
HIP 81724 |
21.07 |
| 2026-02-13 00:00 |
16:43:05.75 |
-17:55:18.2 |
HIP 81724 |
24.26 |
| 2026-02-13 12:00 |
16:43:19.96 |
-17:55:39.5 |
HIP 81899 |
25.38 |
| 2026-02-14 00:00 |
16:43:33.99 |
-17:56:00.3 |
HIP 81899 |
25.21 |
| 2026-02-14 12:00 |
16:43:47.85 |
-17:56:20.7 |
HIP 81899 |
25.47 |
| 2026-02-15 00:00 |
16:44:01.54 |
-17:56:40.5 |
HIP 81899 |
26.14 |
| 2026-02-15 12:00 |
16:44:15.04 |
-17:57:00.0 |
HIP 81899 |
27.17 |
| 2026-02-16 00:00 |
16:44:28.37 |
-17:57:18.8 |
HIP 81899 |
28.51 |
| 2026-02-16 12:00 |
16:44:41.52 |
-17:57:37.2 |
HIP 81899 |
30.10 |
| 2026-02-17 00:00 |
16:44:54.49 |
-17:57:55.2 |
HIP 81899 |
31.89 |
| 2026-02-17 12:00 |
16:45:07.27 |
-17:58:12.7 |
HIP 82120 |
30.58 |
| 2026-02-18 00:00 |
16:45:19.87 |
-17:58:29.7 |
HIP 82120 |
28.85 |
| 2026-02-18 12:00 |
16:45:32.29 |
-17:58:46.3 |
HIP 82120 |
27.38 |
| 2026-02-19 00:00 |
16:45:44.52 |
-17:59:02.4 |
HIP 82120 |
26.16 |
| 2026-02-19 12:00 |
16:45:56.56 |
-17:59:18.0 |
HIP 82120 |
25.24 |
| 2026-02-20 00:00 |
16:46:08.42 |
-17:59:33.2 |
HIP 82120 |
24.63 |
| 2026-02-20 12:00 |
16:46:20.08 |
-17:59:48.0 |
HIP 82120 |
24.33 |
| 2026-02-21 00:00 |
16:46:31.56 |
-18:00:02.2 |
HIP 82120 |
24.35 |
| 2026-02-21 12:00 |
16:46:42.85 |
-18:00:16.1 |
HIP 82120 |
24.65 |
| 2026-02-22 00:00 |
16:46:53.94 |
-18:00:29.5 |
HIP 82120 |
25.23 |
| 2026-02-22 12:00 |
16:47:04.84 |
-18:00:42.4 |
HIP 82120 |
26.05 |
| 2026-02-23 00:00 |
16:47:15.55 |
-18:00:54.9 |
HIP 82120 |
27.07 |
| 2026-02-23 12:00 |
16:47:26.06 |
-18:01:06.9 |
HIP 82120 |
28.26 |
| 2026-02-24 00:00 |
16:47:36.38 |
-18:01:18.6 |
HIP 82120 |
29.58 |