| Parameter |
Value |
| Designation |
C/1985 K1 (Machholz) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1985-06-28T17:43:33.605760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:31Z |
| Obs used |
30 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1985-06-19.0000000 |
| e |
1.00000000 |
| q (au) |
0.106250 |
| a (au) |
- |
| i (deg) |
16.276479 |
| Ω (om, deg) |
195.434274 |
| ω (w, deg) |
274.501133 |
| M (ma, deg) |
- |
Magnitude
Scatter + Global Linear
$$
M_a = (9.225 + 3.309\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.225 |
| n |
3.309 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
0.800 |
| 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) |
| 2026-03-26 00:00 |
19:02:32.45 |
-06:23:34.5 |
HIP 93441 |
10.74 |
| 2026-03-26 12:00 |
19:02:32.77 |
-06:23:26.6 |
HIP 93441 |
10.81 |
| 2026-03-27 00:00 |
19:02:33.07 |
-06:23:18.8 |
HIP 93441 |
10.88 |
| 2026-03-27 12:00 |
19:02:33.36 |
-06:23:10.9 |
HIP 93441 |
10.95 |
| 2026-03-28 00:00 |
19:02:33.64 |
-06:23:03.1 |
HIP 93441 |
11.01 |
| 2026-03-28 12:00 |
19:02:33.90 |
-06:22:55.3 |
HIP 93441 |
11.07 |
| 2026-03-29 00:00 |
19:02:34.14 |
-06:22:47.5 |
HIP 93441 |
11.13 |
| 2026-03-29 12:00 |
19:02:34.37 |
-06:22:39.7 |
HIP 93441 |
11.19 |
| 2026-03-30 00:00 |
19:02:34.58 |
-06:22:31.9 |
HIP 93441 |
11.24 |
| 2026-03-30 12:00 |
19:02:34.78 |
-06:22:24.2 |
HIP 93441 |
11.30 |
| 2026-03-31 00:00 |
19:02:34.97 |
-06:22:16.4 |
HIP 93441 |
11.35 |
| 2026-03-31 12:00 |
19:02:35.13 |
-06:22:08.7 |
HIP 93441 |
11.39 |
| 2026-04-01 00:00 |
19:02:35.29 |
-06:22:01.0 |
HIP 93441 |
11.44 |
| 2026-04-01 12:00 |
19:02:35.42 |
-06:21:53.3 |
HIP 93441 |
11.48 |
| 2026-04-02 00:00 |
19:02:35.55 |
-06:21:45.6 |
HIP 93441 |
11.52 |
| 2026-04-02 12:00 |
19:02:35.65 |
-06:21:38.0 |
HIP 93441 |
11.56 |
| 2026-04-03 00:00 |
19:02:35.75 |
-06:21:30.4 |
HIP 93441 |
11.60 |
| 2026-04-03 12:00 |
19:02:35.82 |
-06:21:22.8 |
HIP 93441 |
11.63 |
| 2026-04-04 00:00 |
19:02:35.88 |
-06:21:15.2 |
HIP 93441 |
11.66 |
| 2026-04-04 12:00 |
19:02:35.93 |
-06:21:07.6 |
HIP 93441 |
11.69 |
| 2026-04-05 00:00 |
19:02:35.96 |
-06:21:00.1 |
HIP 93441 |
11.72 |
| 2026-04-05 12:00 |
19:02:35.98 |
-06:20:52.5 |
HIP 93441 |
11.74 |
| 2026-04-06 00:00 |
19:02:35.98 |
-06:20:45.0 |
HIP 93441 |
11.76 |
| 2026-04-06 12:00 |
19:02:35.96 |
-06:20:37.5 |
HIP 93441 |
11.78 |
| 2026-04-07 00:00 |
19:02:35.93 |
-06:20:30.1 |
HIP 93441 |
11.80 |
| 2026-04-07 12:00 |
19:02:35.89 |
-06:20:22.7 |
HIP 93441 |
11.81 |
| 2026-04-08 00:00 |
19:02:35.83 |
-06:20:15.3 |
HIP 93441 |
11.82 |
| 2026-04-08 12:00 |
19:02:35.75 |
-06:20:07.9 |
HIP 93441 |
11.83 |
| 2026-04-09 00:00 |
19:02:35.66 |
-06:20:00.5 |
HIP 93441 |
11.83 |
| 2026-04-09 12:00 |
19:02:35.55 |
-06:19:53.2 |
HIP 93441 |
11.84 |
| 2026-04-10 00:00 |
19:02:35.43 |
-06:19:45.9 |
HIP 93441 |
11.84 |
| 2026-04-10 12:00 |
19:02:35.29 |
-06:19:38.6 |
HIP 93441 |
11.84 |
| 2026-04-11 00:00 |
19:02:35.14 |
-06:19:31.4 |
HIP 93441 |
11.83 |
| 2026-04-11 12:00 |
19:02:34.97 |
-06:19:24.2 |
HIP 93441 |
11.83 |
| 2026-04-12 00:00 |
19:02:34.79 |
-06:19:17.0 |
HIP 93441 |
11.82 |
| 2026-04-12 12:00 |
19:02:34.59 |
-06:19:09.8 |
HIP 93441 |
11.81 |
| 2026-04-13 00:00 |
19:02:34.38 |
-06:19:02.7 |
HIP 93441 |
11.79 |
| 2026-04-13 12:00 |
19:02:34.15 |
-06:18:55.6 |
HIP 93441 |
11.78 |
| 2026-04-14 00:00 |
19:02:33.91 |
-06:18:48.5 |
HIP 93441 |
11.76 |
| 2026-04-14 12:00 |
19:02:33.65 |
-06:18:41.5 |
HIP 93441 |
11.74 |
| 2026-04-15 00:00 |
19:02:33.38 |
-06:18:34.5 |
HIP 93441 |
11.72 |
| 2026-04-15 12:00 |
19:02:33.09 |
-06:18:27.5 |
HIP 93441 |
11.69 |
| 2026-04-16 00:00 |
19:02:32.78 |
-06:18:20.6 |
HIP 93441 |
11.67 |