| Parameter |
Value |
| Designation |
C/2010 F4 (Machholz) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2010-04-06T02:32:51.809280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:42Z |
| Obs used |
81 |
| NEO |
- |
| M1 |
13.900 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2010-03-30.0000000 |
| e |
1.00003647 |
| q (au) |
0.613826 |
| a (au) |
-16830.797200 |
| i (deg) |
89.145668 |
| Ω (om, deg) |
237.290555 |
| ω (w, deg) |
120.708831 |
| M (ma, deg) |
-0.000003 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.310 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.310 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.804 |
| 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) |
| 2026-06-01 00:00 |
08:21:26.45 |
-75:09:56.0 |
HIP 40725 |
13.80 |
| 2026-06-01 12:00 |
08:21:34.48 |
-75:09:16.4 |
HIP 40725 |
13.79 |
| 2026-06-02 00:00 |
08:21:42.57 |
-75:08:37.1 |
HIP 40725 |
13.83 |
| 2026-06-02 12:00 |
08:21:50.75 |
-75:07:58.0 |
HIP 40725 |
13.93 |
| 2026-06-03 00:00 |
08:21:58.99 |
-75:07:19.2 |
HIP 40725 |
14.09 |
| 2026-06-03 12:00 |
08:22:07.30 |
-75:06:40.6 |
HIP 40725 |
14.30 |
| 2026-06-04 00:00 |
08:22:15.68 |
-75:06:02.3 |
HIP 40725 |
14.56 |
| 2026-06-04 12:00 |
08:22:24.13 |
-75:05:24.2 |
HIP 41254 |
14.69 |
| 2026-06-05 00:00 |
08:22:32.65 |
-75:04:46.3 |
HIP 41254 |
13.86 |
| 2026-06-05 12:00 |
08:22:41.23 |
-75:04:08.7 |
HIP 41254 |
13.02 |
| 2026-06-06 00:00 |
08:22:49.89 |
-75:03:31.4 |
HIP 41254 |
12.19 |
| 2026-06-06 12:00 |
08:22:58.61 |
-75:02:54.3 |
HIP 41254 |
11.35 |
| 2026-06-07 00:00 |
08:23:07.39 |
-75:02:17.5 |
HIP 41254 |
10.52 |
| 2026-06-07 12:00 |
08:23:16.24 |
-75:01:40.9 |
HIP 41254 |
9.68 |
| 2026-06-08 00:00 |
08:23:25.16 |
-75:01:04.7 |
HIP 41254 |
8.85 |
| 2026-06-08 12:00 |
08:23:34.14 |
-75:00:28.6 |
HIP 41254 |
8.01 |
| 2026-06-09 00:00 |
08:23:43.18 |
-74:59:52.9 |
HIP 41254 |
7.18 |
| 2026-06-09 12:00 |
08:23:52.29 |
-74:59:17.4 |
HIP 41254 |
6.34 |
| 2026-06-10 00:00 |
08:24:01.46 |
-74:58:42.2 |
HIP 41254 |
5.51 |
| 2026-06-10 12:00 |
08:24:10.69 |
-74:58:07.2 |
HIP 41254 |
4.67 |
| 2026-06-11 00:00 |
08:24:19.98 |
-74:57:32.5 |
HIP 41254 |
3.84 |
| 2026-06-11 12:00 |
08:24:29.34 |
-74:56:58.2 |
HIP 41254 |
3.01 |
| 2026-06-12 00:00 |
08:24:38.75 |
-74:56:24.1 |
HIP 41254 |
2.17 |
| 2026-06-12 12:00 |
08:24:48.22 |
-74:55:50.2 |
HIP 41254 |
1.35 |
| 2026-06-13 00:00 |
08:24:57.75 |
-74:55:16.7 |
HIP 41254 |
0.57 |
| 2026-06-13 12:00 |
08:25:07.34 |
-74:54:43.4 |
HIP 41254 |
0.46 |
| 2026-06-14 00:00 |
08:25:16.99 |
-74:54:10.5 |
HIP 41254 |
1.22 |
| 2026-06-14 12:00 |
08:25:26.69 |
-74:53:37.8 |
HIP 41254 |
2.04 |
| 2026-06-15 00:00 |
08:25:36.45 |
-74:53:05.4 |
HIP 41254 |
2.87 |
| 2026-06-15 12:00 |
08:25:46.27 |
-74:52:33.4 |
HIP 41273 |
3.42 |
| 2026-06-16 00:00 |
08:25:56.14 |
-74:52:01.6 |
HIP 41273 |
3.50 |
| 2026-06-16 12:00 |
08:26:06.06 |
-74:51:30.1 |
HIP 41273 |
3.78 |
| 2026-06-17 00:00 |
08:26:16.04 |
-74:50:58.9 |
HIP 41273 |
4.20 |
| 2026-06-17 12:00 |
08:26:26.07 |
-74:50:28.1 |
HIP 41273 |
4.75 |
| 2026-06-18 00:00 |
08:26:36.15 |
-74:49:57.5 |
HIP 41273 |
5.37 |
| 2026-06-18 12:00 |
08:26:46.28 |
-74:49:27.2 |
HIP 41273 |
6.05 |
| 2026-06-19 00:00 |
08:26:56.46 |
-74:48:57.3 |
HIP 41273 |
6.76 |
| 2026-06-19 12:00 |
08:27:06.69 |
-74:48:27.6 |
HIP 41273 |
7.50 |
| 2026-06-20 00:00 |
08:27:16.98 |
-74:47:58.3 |
HIP 41273 |
8.26 |
| 2026-06-20 12:00 |
08:27:27.30 |
-74:47:29.3 |
HIP 41273 |
9.04 |
| 2026-06-21 00:00 |
08:27:37.68 |
-74:47:00.6 |
HIP 41273 |
9.83 |
| 2026-06-21 12:00 |
08:27:48.11 |
-74:46:32.2 |
HIP 41273 |
10.62 |
| 2026-06-22 00:00 |
08:27:58.58 |
-74:46:04.1 |
HIP 41565 |
11.42 |