| 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) |
| 2026-05-12 00:00 |
17:50:58.57 |
-80:34:52.0 |
HIP 86626 |
22.46 |
| 2026-05-12 12:00 |
17:50:47.82 |
-80:35:07.4 |
HIP 86626 |
21.97 |
| 2026-05-13 00:00 |
17:50:36.98 |
-80:35:22.5 |
HIP 86626 |
21.48 |
| 2026-05-13 12:00 |
17:50:26.07 |
-80:35:37.4 |
HIP 86626 |
20.99 |
| 2026-05-14 00:00 |
17:50:15.08 |
-80:35:52.0 |
HIP 86626 |
20.50 |
| 2026-05-14 12:00 |
17:50:04.02 |
-80:36:06.5 |
HIP 86626 |
20.01 |
| 2026-05-15 00:00 |
17:49:52.88 |
-80:36:20.7 |
HIP 86626 |
19.52 |
| 2026-05-15 12:00 |
17:49:41.67 |
-80:36:34.8 |
HIP 86626 |
19.03 |
| 2026-05-16 00:00 |
17:49:30.38 |
-80:36:48.6 |
HIP 86626 |
18.53 |
| 2026-05-16 12:00 |
17:49:19.03 |
-80:37:02.2 |
HIP 86626 |
18.04 |
| 2026-05-17 00:00 |
17:49:07.60 |
-80:37:15.6 |
HIP 86626 |
17.54 |
| 2026-05-17 12:00 |
17:48:56.11 |
-80:37:28.7 |
HIP 86626 |
17.05 |
| 2026-05-18 00:00 |
17:48:44.54 |
-80:37:41.6 |
HIP 86626 |
16.55 |
| 2026-05-18 12:00 |
17:48:32.91 |
-80:37:54.3 |
HIP 86626 |
16.05 |
| 2026-05-19 00:00 |
17:48:21.21 |
-80:38:06.8 |
HIP 86626 |
15.56 |
| 2026-05-19 12:00 |
17:48:09.45 |
-80:38:19.0 |
HIP 86626 |
15.06 |
| 2026-05-20 00:00 |
17:47:57.62 |
-80:38:31.0 |
HIP 86626 |
14.56 |
| 2026-05-20 12:00 |
17:47:45.73 |
-80:38:42.8 |
HIP 86626 |
14.06 |
| 2026-05-21 00:00 |
17:47:33.78 |
-80:38:54.3 |
HIP 86626 |
13.56 |
| 2026-05-21 12:00 |
17:47:21.77 |
-80:39:05.7 |
HIP 86626 |
13.06 |
| 2026-05-22 00:00 |
17:47:09.70 |
-80:39:16.7 |
HIP 86626 |
12.56 |
| 2026-05-22 12:00 |
17:46:57.57 |
-80:39:27.6 |
HIP 86626 |
12.06 |
| 2026-05-23 00:00 |
17:46:45.39 |
-80:39:38.2 |
HIP 86626 |
11.56 |
| 2026-05-23 12:00 |
17:46:33.14 |
-80:39:48.5 |
HIP 86626 |
11.07 |
| 2026-05-24 00:00 |
17:46:20.85 |
-80:39:58.6 |
HIP 86626 |
10.57 |
| 2026-05-24 12:00 |
17:46:08.49 |
-80:40:08.5 |
HIP 86626 |
10.07 |
| 2026-05-25 00:00 |
17:45:56.09 |
-80:40:18.2 |
HIP 86626 |
9.58 |
| 2026-05-25 12:00 |
17:45:43.64 |
-80:40:27.6 |
HIP 86626 |
9.08 |
| 2026-05-26 00:00 |
17:45:31.13 |
-80:40:36.7 |
HIP 86626 |
8.59 |
| 2026-05-26 12:00 |
17:45:18.57 |
-80:40:45.6 |
HIP 86626 |
8.10 |
| 2026-05-27 00:00 |
17:45:05.97 |
-80:40:54.3 |
HIP 86626 |
7.61 |
| 2026-05-27 12:00 |
17:44:53.32 |
-80:41:02.7 |
HIP 86626 |
7.13 |
| 2026-05-28 00:00 |
17:44:40.62 |
-80:41:10.9 |
HIP 86626 |
6.66 |
| 2026-05-28 12:00 |
17:44:27.88 |
-80:41:18.8 |
HIP 86626 |
6.18 |
| 2026-05-29 00:00 |
17:44:15.10 |
-80:41:26.5 |
HIP 86626 |
5.72 |
| 2026-05-29 12:00 |
17:44:02.27 |
-80:41:33.9 |
HIP 86626 |
5.27 |
| 2026-05-30 00:00 |
17:43:49.40 |
-80:41:41.1 |
HIP 86626 |
4.83 |
| 2026-05-30 12:00 |
17:43:36.49 |
-80:41:48.0 |
HIP 86626 |
4.41 |
| 2026-05-31 00:00 |
17:43:23.54 |
-80:41:54.7 |
HIP 86626 |
4.02 |
| 2026-05-31 12:00 |
17:43:10.56 |
-80:42:01.1 |
HIP 86626 |
3.65 |
| 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 |