| Parameter |
Value |
| Designation |
C/1994 T1 (Machholz) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1994-10-02T13:22:18.399360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:47Z |
| Obs used |
344 |
| NEO |
- |
| M1 |
10.400 |
| K1 |
5.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1994-11-26.0000000 |
| e |
0.99949492 |
| q (au) |
1.845392 |
| a (au) |
3653.643991 |
| i (deg) |
101.737600 |
| Ω (om, deg) |
249.943625 |
| ω (w, deg) |
142.784278 |
| M (ma, deg) |
0.000243 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.712 + 3.102\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.712 |
| n |
3.102 |
| gf |
1.000 |
| gb |
-0.544 |
| 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) |
| 2026-06-01 00:00 |
17:42:57.53 |
-80:42:07.3 |
HIP 86626 |
3.33 |
| 2026-06-01 12:00 |
17:42:44.47 |
-80:42:13.2 |
HIP 86626 |
3.07 |
| 2026-06-02 00:00 |
17:42:31.38 |
-80:42:18.9 |
HIP 86626 |
2.88 |
| 2026-06-02 12:00 |
17:42:18.25 |
-80:42:24.3 |
HIP 86626 |
2.78 |
| 2026-06-03 00:00 |
17:42:05.09 |
-80:42:29.5 |
HIP 86626 |
2.77 |
| 2026-06-03 12:00 |
17:41:51.90 |
-80:42:34.4 |
HIP 86626 |
2.87 |
| 2026-06-04 00:00 |
17:41:38.68 |
-80:42:39.0 |
HIP 86626 |
3.05 |
| 2026-06-04 12:00 |
17:41:25.43 |
-80:42:43.4 |
HIP 86626 |
3.31 |
| 2026-06-05 00:00 |
17:41:12.15 |
-80:42:47.6 |
HIP 86626 |
3.63 |
| 2026-06-05 12:00 |
17:40:58.85 |
-80:42:51.4 |
HIP 86626 |
4.00 |
| 2026-06-06 00:00 |
17:40:45.52 |
-80:42:55.0 |
HIP 86626 |
4.40 |
| 2026-06-06 12:00 |
17:40:32.17 |
-80:42:58.4 |
HIP 86626 |
4.82 |
| 2026-06-07 00:00 |
17:40:18.79 |
-80:43:01.5 |
HIP 86626 |
5.27 |
| 2026-06-07 12:00 |
17:40:05.40 |
-80:43:04.3 |
HIP 86626 |
5.73 |
| 2026-06-08 00:00 |
17:39:51.98 |
-80:43:06.9 |
HIP 86626 |
6.20 |
| 2026-06-08 12:00 |
17:39:38.54 |
-80:43:09.2 |
HIP 86626 |
6.68 |
| 2026-06-09 00:00 |
17:39:25.09 |
-80:43:11.3 |
HIP 86626 |
7.17 |
| 2026-06-09 12:00 |
17:39:11.62 |
-80:43:13.0 |
HIP 86626 |
7.66 |
| 2026-06-10 00:00 |
17:38:58.13 |
-80:43:14.6 |
HIP 86626 |
8.16 |
| 2026-06-10 12:00 |
17:38:44.63 |
-80:43:15.8 |
HIP 86626 |
8.67 |
| 2026-06-11 00:00 |
17:38:31.12 |
-80:43:16.8 |
HIP 86626 |
9.18 |
| 2026-06-11 12:00 |
17:38:17.60 |
-80:43:17.6 |
HIP 86626 |
9.69 |
| 2026-06-12 00:00 |
17:38:04.06 |
-80:43:18.0 |
HIP 86626 |
10.20 |
| 2026-06-12 12:00 |
17:37:50.52 |
-80:43:18.3 |
HIP 86626 |
10.72 |
| 2026-06-13 00:00 |
17:37:36.97 |
-80:43:18.2 |
HIP 86626 |
11.23 |
| 2026-06-13 12:00 |
17:37:23.41 |
-80:43:17.9 |
HIP 86626 |
11.75 |
| 2026-06-14 00:00 |
17:37:09.85 |
-80:43:17.3 |
HIP 86626 |
12.27 |
| 2026-06-14 12:00 |
17:36:56.28 |
-80:43:16.4 |
HIP 85970 |
12.72 |
| 2026-06-15 00:00 |
17:36:42.72 |
-80:43:15.3 |
HIP 85970 |
12.43 |
| 2026-06-15 12:00 |
17:36:29.15 |
-80:43:13.9 |
HIP 85970 |
12.15 |
| 2026-06-16 00:00 |
17:36:15.58 |
-80:43:12.3 |
HIP 85970 |
11.88 |
| 2026-06-16 12:00 |
17:36:02.02 |
-80:43:10.4 |
HIP 85970 |
11.63 |
| 2026-06-17 00:00 |
17:35:48.46 |
-80:43:08.2 |
HIP 85970 |
11.40 |
| 2026-06-17 12:00 |
17:35:34.90 |
-80:43:05.8 |
HIP 85970 |
11.18 |
| 2026-06-18 00:00 |
17:35:21.35 |
-80:43:03.1 |
HIP 85970 |
10.98 |
| 2026-06-18 12:00 |
17:35:07.81 |
-80:43:00.1 |
HIP 85970 |
10.81 |
| 2026-06-19 00:00 |
17:34:54.28 |
-80:42:56.8 |
HIP 85970 |
10.66 |
| 2026-06-19 12:00 |
17:34:40.76 |
-80:42:53.4 |
HIP 85970 |
10.53 |
| 2026-06-20 00:00 |
17:34:27.25 |
-80:42:49.6 |
HIP 85970 |
10.42 |
| 2026-06-20 12:00 |
17:34:13.75 |
-80:42:45.6 |
HIP 85970 |
10.34 |
| 2026-06-21 00:00 |
17:34:00.26 |
-80:42:41.3 |
HIP 85970 |
10.28 |
| 2026-06-21 12:00 |
17:33:46.79 |
-80:42:36.7 |
HIP 85970 |
10.24 |
| 2026-06-22 00:00 |
17:33:33.34 |
-80:42:31.9 |
HIP 85970 |
10.24 |