| Parameter |
Value |
| Designation |
C/1988 P1 (Machholz) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1988-09-17T13:37:56.176320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:36Z |
| Obs used |
56 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1988-08-19.0000000 |
| e |
0.99999939 |
| q (au) |
0.164552 |
| a (au) |
268133.697775 |
| i (deg) |
40.198656 |
| Ω (om, deg) |
167.727558 |
| ω (w, deg) |
349.037996 |
| M (ma, deg) |
360.000000 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.848 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.848 |
| n |
2.000 |
| gf |
0.982 |
| gb |
-1.000 |
| k |
0.950 |
| 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 |
22:14:05.78 |
+00:34:15.9 |
HIP 109748 |
18.73 |
| 2026-06-01 12:00 |
22:14:05.54 |
+00:34:19.9 |
HIP 109748 |
18.65 |
| 2026-06-02 00:00 |
22:14:05.29 |
+00:34:23.8 |
HIP 109748 |
18.57 |
| 2026-06-02 12:00 |
22:14:05.02 |
+00:34:27.6 |
HIP 109748 |
18.50 |
| 2026-06-03 00:00 |
22:14:04.73 |
+00:34:31.3 |
HIP 109748 |
18.42 |
| 2026-06-03 12:00 |
22:14:04.43 |
+00:34:34.9 |
HIP 109748 |
18.35 |
| 2026-06-04 00:00 |
22:14:04.12 |
+00:34:38.4 |
HIP 109748 |
18.28 |
| 2026-06-04 12:00 |
22:14:03.79 |
+00:34:41.8 |
HIP 109748 |
18.21 |
| 2026-06-05 00:00 |
22:14:03.45 |
+00:34:45.2 |
HIP 109748 |
18.14 |
| 2026-06-05 12:00 |
22:14:03.09 |
+00:34:48.4 |
HIP 109748 |
18.07 |
| 2026-06-06 00:00 |
22:14:02.72 |
+00:34:51.6 |
HIP 109748 |
18.00 |
| 2026-06-06 12:00 |
22:14:02.33 |
+00:34:54.7 |
HIP 109748 |
17.93 |
| 2026-06-07 00:00 |
22:14:01.93 |
+00:34:57.6 |
HIP 109748 |
17.87 |
| 2026-06-07 12:00 |
22:14:01.52 |
+00:35:00.5 |
HIP 109748 |
17.80 |
| 2026-06-08 00:00 |
22:14:01.09 |
+00:35:03.3 |
HIP 109748 |
17.74 |
| 2026-06-08 12:00 |
22:14:00.65 |
+00:35:06.0 |
HIP 109748 |
17.68 |
| 2026-06-09 00:00 |
22:14:00.19 |
+00:35:08.7 |
HIP 109748 |
17.62 |
| 2026-06-09 12:00 |
22:13:59.72 |
+00:35:11.2 |
HIP 109748 |
17.56 |
| 2026-06-10 00:00 |
22:13:59.23 |
+00:35:13.6 |
HIP 109748 |
17.50 |
| 2026-06-10 12:00 |
22:13:58.73 |
+00:35:16.0 |
HIP 109748 |
17.45 |
| 2026-06-11 00:00 |
22:13:58.22 |
+00:35:18.2 |
HIP 109748 |
17.40 |
| 2026-06-11 12:00 |
22:13:57.69 |
+00:35:20.4 |
HIP 109748 |
17.35 |
| 2026-06-12 00:00 |
22:13:57.15 |
+00:35:22.5 |
HIP 109748 |
17.30 |
| 2026-06-12 12:00 |
22:13:56.59 |
+00:35:24.4 |
HIP 109748 |
17.25 |
| 2026-06-13 00:00 |
22:13:56.02 |
+00:35:26.3 |
HIP 109748 |
17.21 |
| 2026-06-13 12:00 |
22:13:55.44 |
+00:35:28.1 |
HIP 109748 |
17.17 |
| 2026-06-14 00:00 |
22:13:54.84 |
+00:35:29.8 |
HIP 109748 |
17.13 |
| 2026-06-14 12:00 |
22:13:54.23 |
+00:35:31.4 |
HIP 109748 |
17.09 |
| 2026-06-15 00:00 |
22:13:53.60 |
+00:35:32.9 |
HIP 109748 |
17.06 |
| 2026-06-15 12:00 |
22:13:52.96 |
+00:35:34.3 |
HIP 109748 |
17.03 |
| 2026-06-16 00:00 |
22:13:52.31 |
+00:35:35.6 |
HIP 109748 |
17.00 |
| 2026-06-16 12:00 |
22:13:51.64 |
+00:35:36.8 |
HIP 109748 |
16.98 |
| 2026-06-17 00:00 |
22:13:50.96 |
+00:35:38.0 |
HIP 109748 |
16.96 |
| 2026-06-17 12:00 |
22:13:50.27 |
+00:35:39.0 |
HIP 109748 |
16.94 |
| 2026-06-18 00:00 |
22:13:49.56 |
+00:35:39.9 |
HIP 109748 |
16.93 |
| 2026-06-18 12:00 |
22:13:48.84 |
+00:35:40.8 |
HIP 109748 |
16.92 |
| 2026-06-19 00:00 |
22:13:48.10 |
+00:35:41.5 |
HIP 109748 |
16.91 |
| 2026-06-19 12:00 |
22:13:47.35 |
+00:35:42.2 |
HIP 109748 |
16.90 |
| 2026-06-20 00:00 |
22:13:46.59 |
+00:35:42.7 |
HIP 109748 |
16.90 |
| 2026-06-20 12:00 |
22:13:45.82 |
+00:35:43.2 |
HIP 109748 |
16.91 |
| 2026-06-21 00:00 |
22:13:45.03 |
+00:35:43.6 |
HIP 109748 |
16.92 |
| 2026-06-21 12:00 |
22:13:44.23 |
+00:35:43.9 |
HIP 109748 |
16.93 |
| 2026-06-22 00:00 |
22:13:43.41 |
+00:35:44.0 |
HIP 109748 |
16.95 |