C/2010 F4 (Machholz)
| 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) |
| 2026-02-03 00:00 |
08:38:00.53 |
-77:38:57.3 |
HIP 42416 |
3.94 |
| 2026-02-03 12:00 |
08:37:45.56 |
-77:38:53.1 |
HIP 42416 |
4.58 |
| 2026-02-04 00:00 |
08:37:30.61 |
-77:38:48.4 |
HIP 42416 |
5.26 |
| 2026-02-04 12:00 |
08:37:15.68 |
-77:38:43.2 |
HIP 42416 |
5.97 |
| 2026-02-05 00:00 |
08:37:00.78 |
-77:38:37.5 |
HIP 42416 |
6.69 |
| 2026-02-05 12:00 |
08:36:45.90 |
-77:38:31.4 |
HIP 42416 |
7.43 |
| 2026-02-06 00:00 |
08:36:31.05 |
-77:38:24.7 |
HIP 42416 |
8.18 |
| 2026-02-06 12:00 |
08:36:16.22 |
-77:38:17.5 |
HIP 42416 |
8.93 |
| 2026-02-07 00:00 |
08:36:01.42 |
-77:38:09.9 |
HIP 42416 |
9.69 |
| 2026-02-07 12:00 |
08:35:46.66 |
-77:38:01.7 |
HIP 42416 |
10.46 |
| 2026-02-08 00:00 |
08:35:31.92 |
-77:37:53.1 |
HIP 42416 |
11.22 |
| 2026-02-08 12:00 |
08:35:17.22 |
-77:37:44.0 |
HIP 42416 |
11.99 |
| 2026-02-09 00:00 |
08:35:02.56 |
-77:37:34.4 |
HIP 42416 |
12.76 |
| 2026-02-09 12:00 |
08:34:47.93 |
-77:37:24.3 |
HIP 42416 |
13.54 |
| 2026-02-10 00:00 |
08:34:33.34 |
-77:37:13.7 |
HIP 42416 |
14.31 |
| 2026-02-10 12:00 |
08:34:18.79 |
-77:37:02.6 |
HIP 42416 |
15.09 |
| 2026-02-11 00:00 |
08:34:04.29 |
-77:36:51.1 |
HIP 42416 |
15.86 |
| 2026-02-11 12:00 |
08:33:49.82 |
-77:36:39.1 |
HIP 42416 |
16.64 |
| 2026-02-12 00:00 |
08:33:35.41 |
-77:36:26.5 |
HIP 42416 |
17.41 |
| 2026-02-12 12:00 |
08:33:21.04 |
-77:36:13.6 |
HIP 42416 |
18.19 |
| 2026-02-13 00:00 |
08:33:06.71 |
-77:36:00.1 |
HIP 42416 |
18.97 |
| 2026-02-13 12:00 |
08:32:52.44 |
-77:35:46.1 |
HIP 41453 |
19.55 |
| 2026-02-14 00:00 |
08:32:38.22 |
-77:35:31.7 |
HIP 41453 |
18.97 |
| 2026-02-14 12:00 |
08:32:24.05 |
-77:35:16.8 |
HIP 41453 |
18.40 |
| 2026-02-15 00:00 |
08:32:09.93 |
-77:35:01.4 |
HIP 41453 |
17.86 |
| 2026-02-15 12:00 |
08:31:55.88 |
-77:34:45.6 |
HIP 41453 |
17.35 |
| 2026-02-16 00:00 |
08:31:41.88 |
-77:34:29.3 |
HIP 41453 |
16.86 |
| 2026-02-16 12:00 |
08:31:27.93 |
-77:34:12.5 |
HIP 41453 |
16.41 |
| 2026-02-17 00:00 |
08:31:14.05 |
-77:33:55.3 |
HIP 41453 |
15.99 |
| 2026-02-17 12:00 |
08:31:00.23 |
-77:33:37.6 |
HIP 41453 |
15.60 |
| 2026-02-18 00:00 |
08:30:46.48 |
-77:33:19.4 |
HIP 41453 |
15.26 |
| 2026-02-18 12:00 |
08:30:32.79 |
-77:33:00.8 |
HIP 41453 |
14.96 |
| 2026-02-19 00:00 |
08:30:19.17 |
-77:32:41.7 |
HIP 41453 |
14.70 |
| 2026-02-19 12:00 |
08:30:05.61 |
-77:32:22.2 |
HIP 41453 |
14.49 |
| 2026-02-20 00:00 |
08:29:52.13 |
-77:32:02.2 |
HIP 41453 |
14.32 |
| 2026-02-20 12:00 |
08:29:38.71 |
-77:31:41.8 |
HIP 41453 |
14.21 |
| 2026-02-21 00:00 |
08:29:25.37 |
-77:31:20.9 |
HIP 41453 |
14.15 |
| 2026-02-21 12:00 |
08:29:12.10 |
-77:30:59.6 |
HIP 41453 |
14.15 |
| 2026-02-22 00:00 |
08:28:58.91 |
-77:30:37.8 |
HIP 41453 |
14.19 |
| 2026-02-22 12:00 |
08:28:45.79 |
-77:30:15.6 |
HIP 41453 |
14.29 |
| 2026-02-23 00:00 |
08:28:32.75 |
-77:29:53.0 |
HIP 41453 |
14.44 |
| 2026-02-23 12:00 |
08:28:19.79 |
-77:29:29.9 |
HIP 41453 |
14.64 |
| 2026-02-24 00:00 |
08:28:06.91 |
-77:29:06.4 |
HIP 41453 |
14.88 |