| 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) |
| 2026-07-29 00:00 |
08:42:19.13 |
-74:27:22.4 |
HIP 42690 |
9.24 |
| 2026-07-29 12:00 |
08:42:31.34 |
-74:27:20.9 |
HIP 42690 |
9.38 |
| 2026-07-30 00:00 |
08:42:43.55 |
-74:27:19.8 |
HIP 42690 |
9.59 |
| 2026-07-30 12:00 |
08:42:55.76 |
-74:27:19.0 |
HIP 42690 |
9.86 |
| 2026-07-31 00:00 |
08:43:07.96 |
-74:27:18.7 |
HIP 42858 |
9.83 |
| 2026-07-31 12:00 |
08:43:20.17 |
-74:27:18.7 |
HIP 42858 |
9.57 |
| 2026-08-01 00:00 |
08:43:32.38 |
-74:27:19.0 |
HIP 42858 |
9.37 |
| 2026-08-01 12:00 |
08:43:44.58 |
-74:27:19.8 |
HIP 42858 |
9.25 |
| 2026-08-02 00:00 |
08:43:56.78 |
-74:27:20.9 |
HIP 42858 |
9.21 |
| 2026-08-02 12:00 |
08:44:08.98 |
-74:27:22.4 |
HIP 42858 |
9.24 |
| 2026-08-03 00:00 |
08:44:21.17 |
-74:27:24.2 |
HIP 42858 |
9.36 |
| 2026-08-03 12:00 |
08:44:33.36 |
-74:27:26.5 |
HIP 42858 |
9.55 |
| 2026-08-04 00:00 |
08:44:45.54 |
-74:27:29.1 |
HIP 42858 |
9.81 |
| 2026-08-04 12:00 |
08:44:57.72 |
-74:27:32.1 |
HIP 42858 |
10.14 |
| 2026-08-05 00:00 |
08:45:09.89 |
-74:27:35.4 |
HIP 42858 |
10.52 |
| 2026-08-05 12:00 |
08:45:22.05 |
-74:27:39.1 |
HIP 42858 |
10.96 |
| 2026-08-06 00:00 |
08:45:34.21 |
-74:27:43.2 |
HIP 42858 |
11.45 |
| 2026-08-06 12:00 |
08:45:46.36 |
-74:27:47.7 |
HIP 42858 |
11.98 |
| 2026-08-07 00:00 |
08:45:58.50 |
-74:27:52.6 |
HIP 42858 |
12.54 |
| 2026-08-07 12:00 |
08:46:10.63 |
-74:27:57.8 |
HIP 42858 |
13.14 |
| 2026-08-08 00:00 |
08:46:22.75 |
-74:28:03.4 |
HIP 42858 |
13.76 |
| 2026-08-08 12:00 |
08:46:34.86 |
-74:28:09.4 |
HIP 42858 |
14.40 |
| 2026-08-09 00:00 |
08:46:46.96 |
-74:28:15.7 |
HIP 42858 |
15.07 |
| 2026-08-09 12:00 |
08:46:59.05 |
-74:28:22.4 |
HIP 42858 |
15.75 |
| 2026-08-10 00:00 |
08:47:11.13 |
-74:28:29.5 |
HIP 42858 |
16.45 |
| 2026-08-10 12:00 |
08:47:23.19 |
-74:28:37.0 |
HIP 42858 |
17.17 |
| 2026-08-11 00:00 |
08:47:35.24 |
-74:28:44.8 |
HIP 42858 |
17.89 |
| 2026-08-11 12:00 |
08:47:47.28 |
-74:28:53.1 |
HIP 42858 |
18.63 |
| 2026-08-12 00:00 |
08:47:59.30 |
-74:29:01.7 |
HIP 42858 |
19.37 |
| 2026-08-12 12:00 |
08:48:11.30 |
-74:29:10.6 |
HIP 42858 |
20.13 |
| 2026-08-13 00:00 |
08:48:23.29 |
-74:29:19.9 |
HIP 42858 |
20.89 |
| 2026-08-13 12:00 |
08:48:35.26 |
-74:29:29.7 |
HIP 42858 |
21.66 |
| 2026-08-14 00:00 |
08:48:47.22 |
-74:29:39.7 |
HIP 42858 |
22.43 |
| 2026-08-14 12:00 |
08:48:59.15 |
-74:29:50.2 |
HIP 43598 |
22.81 |
| 2026-08-15 00:00 |
08:49:11.07 |
-74:30:01.0 |
HIP 43598 |
22.16 |
| 2026-08-15 12:00 |
08:49:22.97 |
-74:30:12.2 |
HIP 43598 |
21.51 |
| 2026-08-16 00:00 |
08:49:34.85 |
-74:30:23.7 |
HIP 43598 |
20.87 |
| 2026-08-16 12:00 |
08:49:46.70 |
-74:30:35.7 |
HIP 43598 |
20.24 |
| 2026-08-17 00:00 |
08:49:58.54 |
-74:30:47.9 |
HIP 43598 |
19.62 |
| 2026-08-17 12:00 |
08:50:10.35 |
-74:31:00.6 |
HIP 43598 |
19.01 |
| 2026-08-18 00:00 |
08:50:22.14 |
-74:31:13.6 |
HIP 43598 |
18.41 |
| 2026-08-18 12:00 |
08:50:33.91 |
-74:31:27.0 |
HIP 43598 |
17.83 |
| 2026-08-19 00:00 |
08:50:45.65 |
-74:31:40.7 |
HIP 43598 |
17.25 |