| Parameter |
Value |
| Designation |
45P/Honda-Mrkos-Pajdusakova |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2016-12-31T06:49:10.395840Z |
| Orbit solution date (soln_date, UTC) |
2022-07-19T02:06:34Z |
| Obs used |
1823 |
| NEO |
Yes |
| M1 |
13.700 |
| K1 |
22.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-08-14.0000000 |
| e |
0.82399608 |
| q (au) |
0.532650 |
| a (au) |
3.026354 |
| i (deg) |
4.248171 |
| Ω (om, deg) |
88.934602 |
| ω (w, deg) |
326.344198 |
| M (ma, deg) |
42.255824 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.983 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.983 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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) |
| 2026-05-12 00:00 |
17:18:42.87 |
-21:49:35.8 |
HIP 84798 |
24.97 |
| 2026-05-12 12:00 |
17:18:21.42 |
-21:49:16.8 |
HIP 84491 |
27.35 |
| 2026-05-13 00:00 |
17:17:59.76 |
-21:48:57.4 |
HIP 84491 |
22.38 |
| 2026-05-13 12:00 |
17:17:37.88 |
-21:48:37.7 |
HIP 84491 |
17.39 |
| 2026-05-14 00:00 |
17:17:15.78 |
-21:48:17.7 |
HIP 84491 |
12.44 |
| 2026-05-14 12:00 |
17:16:53.48 |
-21:47:57.4 |
HIP 84491 |
7.70 |
| 2026-05-15 00:00 |
17:16:30.97 |
-21:47:36.8 |
HIP 84491 |
4.17 |
| 2026-05-15 12:00 |
17:16:08.26 |
-21:47:15.9 |
HIP 84491 |
5.55 |
| 2026-05-16 00:00 |
17:15:45.35 |
-21:46:54.7 |
HIP 84491 |
10.04 |
| 2026-05-16 12:00 |
17:15:22.23 |
-21:46:33.1 |
HIP 84491 |
15.14 |
| 2026-05-17 00:00 |
17:14:58.92 |
-21:46:11.2 |
HIP 84491 |
20.42 |
| 2026-05-17 12:00 |
17:14:35.42 |
-21:45:49.0 |
HIP 84491 |
25.81 |
| 2026-05-18 00:00 |
17:14:11.73 |
-21:45:26.5 |
HIP 84198 |
23.27 |
| 2026-05-18 12:00 |
17:13:47.85 |
-21:45:03.7 |
HIP 84198 |
18.10 |
| 2026-05-19 00:00 |
17:13:23.79 |
-21:44:40.5 |
HIP 84198 |
13.23 |
| 2026-05-19 12:00 |
17:12:59.55 |
-21:44:17.0 |
HIP 84198 |
9.19 |
| 2026-05-20 00:00 |
17:12:35.13 |
-21:43:53.2 |
HIP 84198 |
7.59 |
| 2026-05-20 12:00 |
17:12:10.54 |
-21:43:29.0 |
HIP 84135 |
4.28 |
| 2026-05-21 00:00 |
17:11:45.78 |
-21:43:04.6 |
HIP 84135 |
6.04 |
| 2026-05-21 12:00 |
17:11:20.85 |
-21:42:39.8 |
HIP 84135 |
11.04 |
| 2026-05-22 00:00 |
17:10:55.76 |
-21:42:14.7 |
HIP 83969 |
16.07 |
| 2026-05-22 12:00 |
17:10:30.52 |
-21:41:49.2 |
HIP 83969 |
10.92 |
| 2026-05-23 00:00 |
17:10:05.11 |
-21:41:23.4 |
HIP 83969 |
7.02 |
| 2026-05-23 12:00 |
17:09:39.55 |
-21:40:57.3 |
HIP 83969 |
7.04 |
| 2026-05-24 00:00 |
17:09:13.85 |
-21:40:30.9 |
HIP 83969 |
11.02 |
| 2026-05-24 12:00 |
17:08:47.99 |
-21:40:04.1 |
HIP 83969 |
16.30 |
| 2026-05-25 00:00 |
17:08:22.00 |
-21:39:37.1 |
HIP 83969 |
22.01 |
| 2026-05-25 12:00 |
17:07:55.87 |
-21:39:09.6 |
HIP 83684 |
24.76 |
| 2026-05-26 00:00 |
17:07:29.60 |
-21:38:41.9 |
HIP 83684 |
18.72 |
| 2026-05-26 12:00 |
17:07:03.21 |
-21:38:13.8 |
HIP 83684 |
12.72 |
| 2026-05-27 00:00 |
17:06:36.68 |
-21:37:45.4 |
HIP 83684 |
6.97 |
| 2026-05-27 12:00 |
17:06:10.04 |
-21:37:16.7 |
HIP 83684 |
3.44 |
| 2026-05-28 00:00 |
17:05:43.27 |
-21:36:47.7 |
HIP 83684 |
7.25 |
| 2026-05-28 12:00 |
17:05:16.39 |
-21:36:18.3 |
HIP 83684 |
13.11 |
| 2026-05-29 00:00 |
17:04:49.39 |
-21:35:48.6 |
HIP 83482 |
19.11 |
| 2026-05-29 12:00 |
17:04:22.29 |
-21:35:18.6 |
HIP 83482 |
14.05 |
| 2026-05-30 00:00 |
17:03:55.09 |
-21:34:48.3 |
HIP 83482 |
10.45 |
| 2026-05-30 12:00 |
17:03:27.78 |
-21:34:17.6 |
HIP 83482 |
10.08 |
| 2026-05-31 00:00 |
17:03:00.38 |
-21:33:46.7 |
HIP 83482 |
13.26 |
| 2026-05-31 12:00 |
17:02:32.88 |
-21:33:15.4 |
HIP 83482 |
18.22 |
| 2026-06-01 00:00 |
17:02:05.30 |
-21:32:43.8 |
HIP 83224 |
22.79 |
| 2026-06-01 12:00 |
17:01:37.63 |
-21:32:12.0 |
HIP 83224 |
16.43 |
| 2026-06-02 00:00 |
17:01:09.88 |
-21:31:39.8 |
HIP 83224 |
10.15 |