| Parameter |
Value |
| Designation |
C/2000 A1 (Montani) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2000-07-13T05:54:09.682560Z |
| Orbit solution date (soln_date, UTC) |
2025-09-09T12:42:30Z |
| Obs used |
135 |
| NEO |
- |
| M1 |
4.400 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2000-07-31.0000000 |
| e |
1.00401459 |
| q (au) |
9.743100 |
| a (au) |
-2426.925294 |
| i (deg) |
24.541886 |
| Ω (om, deg) |
111.835138 |
| ω (w, deg) |
14.271337 |
| M (ma, deg) |
0.000146 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.448 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.448 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.861 |
| 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) |
| 2026-09-20 00:00 |
16:42:46.39 |
-05:40:31.2 |
HIP 81952 |
24.96 |
| 2026-09-20 12:00 |
16:42:47.42 |
-05:40:46.1 |
HIP 81952 |
24.70 |
| 2026-09-21 00:00 |
16:42:48.47 |
-05:41:00.9 |
HIP 81952 |
24.43 |
| 2026-09-21 12:00 |
16:42:49.55 |
-05:41:15.8 |
HIP 81952 |
24.17 |
| 2026-09-22 00:00 |
16:42:50.64 |
-05:41:30.6 |
HIP 81952 |
23.90 |
| 2026-09-22 12:00 |
16:42:51.76 |
-05:41:45.5 |
HIP 81952 |
23.62 |
| 2026-09-23 00:00 |
16:42:52.90 |
-05:42:00.4 |
HIP 81952 |
23.34 |
| 2026-09-23 12:00 |
16:42:54.06 |
-05:42:15.3 |
HIP 81952 |
23.07 |
| 2026-09-24 00:00 |
16:42:55.25 |
-05:42:30.2 |
HIP 81952 |
22.78 |
| 2026-09-24 12:00 |
16:42:56.45 |
-05:42:45.1 |
HIP 81952 |
22.50 |
| 2026-09-25 00:00 |
16:42:57.68 |
-05:43:00.0 |
HIP 81952 |
22.21 |
| 2026-09-25 12:00 |
16:42:58.93 |
-05:43:14.9 |
HIP 81952 |
21.92 |
| 2026-09-26 00:00 |
16:43:00.20 |
-05:43:29.8 |
HIP 81952 |
21.63 |
| 2026-09-26 12:00 |
16:43:01.50 |
-05:43:44.7 |
HIP 81952 |
21.34 |
| 2026-09-27 00:00 |
16:43:02.81 |
-05:43:59.6 |
HIP 81952 |
21.05 |
| 2026-09-27 12:00 |
16:43:04.15 |
-05:44:14.5 |
HIP 81952 |
20.75 |
| 2026-09-28 00:00 |
16:43:05.51 |
-05:44:29.4 |
HIP 81952 |
20.46 |
| 2026-09-28 12:00 |
16:43:06.89 |
-05:44:44.3 |
HIP 81952 |
20.16 |
| 2026-09-29 00:00 |
16:43:08.29 |
-05:44:59.2 |
HIP 81952 |
19.86 |
| 2026-09-29 12:00 |
16:43:09.71 |
-05:45:14.0 |
HIP 81952 |
19.56 |
| 2026-09-30 00:00 |
16:43:11.15 |
-05:45:28.9 |
HIP 81952 |
19.26 |
| 2026-09-30 12:00 |
16:43:12.62 |
-05:45:43.8 |
HIP 81952 |
18.97 |
| 2026-10-01 00:00 |
16:43:14.10 |
-05:45:58.7 |
HIP 81952 |
18.67 |
| 2026-10-01 12:00 |
16:43:15.61 |
-05:46:13.5 |
HIP 81952 |
18.37 |
| 2026-10-02 00:00 |
16:43:17.13 |
-05:46:28.4 |
HIP 81952 |
18.08 |
| 2026-10-02 12:00 |
16:43:18.68 |
-05:46:43.2 |
HIP 81952 |
17.78 |
| 2026-10-03 00:00 |
16:43:20.25 |
-05:46:58.0 |
HIP 81952 |
17.49 |
| 2026-10-03 12:00 |
16:43:21.84 |
-05:47:12.8 |
HIP 81952 |
17.20 |
| 2026-10-04 00:00 |
16:43:23.45 |
-05:47:27.6 |
HIP 81952 |
16.92 |
| 2026-10-04 12:00 |
16:43:25.08 |
-05:47:42.4 |
HIP 81952 |
16.64 |
| 2026-10-05 00:00 |
16:43:26.73 |
-05:47:57.2 |
HIP 81952 |
16.36 |
| 2026-10-05 12:00 |
16:43:28.40 |
-05:48:12.0 |
HIP 81952 |
16.09 |
| 2026-10-06 00:00 |
16:43:30.09 |
-05:48:26.7 |
HIP 81952 |
15.82 |
| 2026-10-06 12:00 |
16:43:31.80 |
-05:48:41.4 |
HIP 81952 |
15.56 |
| 2026-10-07 00:00 |
16:43:33.53 |
-05:48:56.1 |
HIP 81952 |
15.30 |
| 2026-10-07 12:00 |
16:43:35.28 |
-05:49:10.8 |
HIP 81952 |
15.06 |
| 2026-10-08 00:00 |
16:43:37.05 |
-05:49:25.5 |
HIP 81952 |
14.82 |
| 2026-10-08 12:00 |
16:43:38.84 |
-05:49:40.1 |
HIP 81952 |
14.59 |
| 2026-10-09 00:00 |
16:43:40.65 |
-05:49:54.7 |
HIP 81952 |
14.37 |
| 2026-10-09 12:00 |
16:43:42.48 |
-05:50:09.3 |
HIP 81952 |
14.16 |
| 2026-10-10 00:00 |
16:43:44.33 |
-05:50:23.9 |
HIP 81952 |
13.96 |
| 2026-10-10 12:00 |
16:43:46.20 |
-05:50:38.4 |
HIP 81952 |
13.78 |
| 2026-10-11 00:00 |
16:43:48.08 |
-05:50:53.0 |
HIP 81952 |
13.61 |