C/1978 R3 (Machholz)
| Parameter |
Value |
| Designation |
C/1978 R3 (Machholz) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1978-08-13T16:08:35.136960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:27Z |
| Obs used |
46 |
| NEO |
- |
| M1 |
8.300 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1978-11-02.0000000 |
| e |
1.00028144 |
| q (au) |
1.771588 |
| a (au) |
-6294.758943 |
| i (deg) |
130.636426 |
| Ω (om, deg) |
290.677833 |
| ω (w, deg) |
224.754011 |
| M (ma, deg) |
0.000159 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.180 + 2.924\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.180 |
| n |
2.924 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
18:11:49.33 |
-03:40:36.1 |
HIP 89236 |
16.37 |
| 2026-02-03 12:00 |
18:11:50.55 |
-03:40:29.8 |
HIP 89236 |
16.08 |
| 2026-02-04 00:00 |
18:11:51.76 |
-03:40:23.5 |
HIP 89236 |
15.79 |
| 2026-02-04 12:00 |
18:11:52.96 |
-03:40:17.0 |
HIP 89236 |
15.51 |
| 2026-02-05 00:00 |
18:11:54.15 |
-03:40:10.6 |
HIP 89236 |
15.23 |
| 2026-02-05 12:00 |
18:11:55.34 |
-03:40:04.1 |
HIP 89236 |
14.94 |
| 2026-02-06 00:00 |
18:11:56.51 |
-03:39:57.5 |
HIP 89236 |
14.67 |
| 2026-02-06 12:00 |
18:11:57.67 |
-03:39:50.9 |
HIP 89236 |
14.39 |
| 2026-02-07 00:00 |
18:11:58.82 |
-03:39:44.3 |
HIP 89236 |
14.12 |
| 2026-02-07 12:00 |
18:11:59.96 |
-03:39:37.5 |
HIP 89236 |
13.84 |
| 2026-02-08 00:00 |
18:12:01.09 |
-03:39:30.8 |
HIP 89236 |
13.58 |
| 2026-02-08 12:00 |
18:12:02.22 |
-03:39:24.0 |
HIP 89236 |
13.31 |
| 2026-02-09 00:00 |
18:12:03.33 |
-03:39:17.1 |
HIP 89236 |
13.04 |
| 2026-02-09 12:00 |
18:12:04.43 |
-03:39:10.2 |
HIP 89236 |
12.78 |
| 2026-02-10 00:00 |
18:12:05.52 |
-03:39:03.3 |
HIP 89236 |
12.52 |
| 2026-02-10 12:00 |
18:12:06.60 |
-03:38:56.3 |
HIP 89236 |
12.27 |
| 2026-02-11 00:00 |
18:12:07.67 |
-03:38:49.2 |
HIP 89236 |
12.02 |
| 2026-02-11 12:00 |
18:12:08.72 |
-03:38:42.1 |
HIP 89236 |
11.76 |
| 2026-02-12 00:00 |
18:12:09.77 |
-03:38:35.0 |
HIP 89236 |
11.52 |
| 2026-02-12 12:00 |
18:12:10.81 |
-03:38:27.8 |
HIP 89236 |
11.27 |
| 2026-02-13 00:00 |
18:12:11.83 |
-03:38:20.6 |
HIP 89236 |
11.03 |
| 2026-02-13 12:00 |
18:12:12.85 |
-03:38:13.3 |
HIP 89236 |
10.79 |
| 2026-02-14 00:00 |
18:12:13.85 |
-03:38:06.0 |
HIP 89236 |
10.55 |
| 2026-02-14 12:00 |
18:12:14.84 |
-03:37:58.6 |
HIP 89236 |
10.32 |
| 2026-02-15 00:00 |
18:12:15.82 |
-03:37:51.2 |
HIP 89236 |
10.09 |
| 2026-02-15 12:00 |
18:12:16.79 |
-03:37:43.8 |
HIP 89236 |
9.86 |
| 2026-02-16 00:00 |
18:12:17.75 |
-03:37:36.3 |
HIP 89236 |
9.63 |
| 2026-02-16 12:00 |
18:12:18.69 |
-03:37:28.8 |
HIP 89236 |
9.41 |
| 2026-02-17 00:00 |
18:12:19.63 |
-03:37:21.2 |
HIP 89236 |
9.19 |
| 2026-02-17 12:00 |
18:12:20.55 |
-03:37:13.6 |
HIP 89236 |
8.98 |
| 2026-02-18 00:00 |
18:12:21.46 |
-03:37:06.0 |
HIP 89236 |
8.77 |
| 2026-02-18 12:00 |
18:12:22.36 |
-03:36:58.3 |
HIP 89236 |
8.56 |
| 2026-02-19 00:00 |
18:12:23.25 |
-03:36:50.6 |
HIP 89236 |
8.35 |
| 2026-02-19 12:00 |
18:12:24.12 |
-03:36:42.8 |
HIP 89236 |
8.15 |
| 2026-02-20 00:00 |
18:12:24.99 |
-03:36:35.1 |
HIP 89236 |
7.95 |
| 2026-02-20 12:00 |
18:12:25.84 |
-03:36:27.2 |
HIP 89236 |
7.76 |
| 2026-02-21 00:00 |
18:12:26.67 |
-03:36:19.4 |
HIP 89236 |
7.56 |
| 2026-02-21 12:00 |
18:12:27.50 |
-03:36:11.5 |
HIP 89236 |
7.38 |
| 2026-02-22 00:00 |
18:12:28.31 |
-03:36:03.5 |
HIP 89236 |
7.19 |
| 2026-02-22 12:00 |
18:12:29.11 |
-03:35:55.6 |
HIP 89236 |
7.01 |
| 2026-02-23 00:00 |
18:12:29.90 |
-03:35:47.6 |
HIP 89236 |
6.83 |
| 2026-02-23 12:00 |
18:12:30.68 |
-03:35:39.5 |
HIP 89236 |
6.66 |
| 2026-02-24 00:00 |
18:12:31.44 |
-03:35:31.5 |
HIP 89236 |
6.49 |