| Parameter |
Value |
| Designation |
C/1997 G2 (Montani) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-04-16T07:14:20.978880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:50Z |
| Obs used |
187 |
| NEO |
- |
| M1 |
6.400 |
| K1 |
13.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1997-07-26.0000000 |
| e |
0.99416325 |
| q (au) |
3.084963 |
| a (au) |
528.541310 |
| i (deg) |
69.835498 |
| Ω (om, deg) |
55.802519 |
| ω (w, deg) |
239.843035 |
| M (ma, deg) |
359.978562 |
Magnitude
Scatter + Global Linear
$$
M_a = (4.554 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
4.554 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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) |
| 2026-05-12 00:00 |
03:53:35.86 |
+49:54:00.0 |
HIP 18282 |
13.13 |
| 2026-05-12 12:00 |
03:53:39.46 |
+49:54:05.1 |
HIP 18282 |
12.77 |
| 2026-05-13 00:00 |
03:53:43.06 |
+49:54:10.4 |
HIP 18282 |
12.43 |
| 2026-05-13 12:00 |
03:53:46.66 |
+49:54:15.9 |
HIP 18282 |
12.11 |
| 2026-05-14 00:00 |
03:53:50.27 |
+49:54:21.5 |
HIP 18282 |
11.81 |
| 2026-05-14 12:00 |
03:53:53.89 |
+49:54:27.2 |
HIP 18282 |
11.53 |
| 2026-05-15 00:00 |
03:53:57.50 |
+49:54:33.1 |
HIP 18282 |
11.28 |
| 2026-05-15 12:00 |
03:54:01.12 |
+49:54:39.2 |
HIP 18282 |
11.06 |
| 2026-05-16 00:00 |
03:54:04.75 |
+49:54:45.4 |
HIP 18282 |
10.86 |
| 2026-05-16 12:00 |
03:54:08.37 |
+49:54:51.8 |
HIP 18282 |
10.70 |
| 2026-05-17 00:00 |
03:54:12.00 |
+49:54:58.3 |
HIP 18282 |
10.57 |
| 2026-05-17 12:00 |
03:54:15.63 |
+49:55:04.9 |
HIP 18282 |
10.48 |
| 2026-05-18 00:00 |
03:54:19.27 |
+49:55:11.7 |
HIP 18282 |
10.42 |
| 2026-05-18 12:00 |
03:54:22.90 |
+49:55:18.7 |
HIP 18282 |
10.40 |
| 2026-05-19 00:00 |
03:54:26.54 |
+49:55:25.8 |
HIP 18282 |
10.42 |
| 2026-05-19 12:00 |
03:54:30.18 |
+49:55:33.0 |
HIP 18282 |
10.47 |
| 2026-05-20 00:00 |
03:54:33.82 |
+49:55:40.4 |
HIP 18282 |
10.55 |
| 2026-05-20 12:00 |
03:54:37.46 |
+49:55:47.9 |
HIP 18282 |
10.68 |
| 2026-05-21 00:00 |
03:54:41.10 |
+49:55:55.6 |
HIP 18282 |
10.83 |
| 2026-05-21 12:00 |
03:54:44.74 |
+49:56:03.4 |
HIP 18282 |
11.02 |
| 2026-05-22 00:00 |
03:54:48.38 |
+49:56:11.3 |
HIP 18282 |
11.25 |
| 2026-05-22 12:00 |
03:54:52.03 |
+49:56:19.4 |
HIP 18282 |
11.50 |
| 2026-05-23 00:00 |
03:54:55.67 |
+49:56:27.7 |
HIP 18282 |
11.78 |
| 2026-05-23 12:00 |
03:54:59.31 |
+49:56:36.0 |
HIP 18282 |
12.08 |
| 2026-05-24 00:00 |
03:55:02.95 |
+49:56:44.6 |
HIP 18282 |
12.41 |
| 2026-05-24 12:00 |
03:55:06.59 |
+49:56:53.2 |
HIP 18282 |
12.76 |
| 2026-05-25 00:00 |
03:55:10.23 |
+49:57:02.0 |
HIP 18282 |
13.13 |
| 2026-05-25 12:00 |
03:55:13.86 |
+49:57:10.9 |
HIP 18282 |
13.52 |
| 2026-05-26 00:00 |
03:55:17.50 |
+49:57:20.0 |
HIP 18282 |
13.93 |
| 2026-05-26 12:00 |
03:55:21.13 |
+49:57:29.2 |
HIP 18282 |
14.35 |
| 2026-05-27 00:00 |
03:55:24.76 |
+49:57:38.6 |
HIP 18282 |
14.79 |
| 2026-05-27 12:00 |
03:55:28.39 |
+49:57:48.1 |
HIP 18282 |
15.24 |
| 2026-05-28 00:00 |
03:55:32.01 |
+49:57:57.7 |
HIP 18282 |
15.70 |
| 2026-05-28 12:00 |
03:55:35.64 |
+49:58:07.4 |
HIP 18282 |
16.18 |
| 2026-05-29 00:00 |
03:55:39.26 |
+49:58:17.3 |
HIP 18282 |
16.66 |
| 2026-05-29 12:00 |
03:55:42.87 |
+49:58:27.3 |
HIP 18282 |
17.15 |
| 2026-05-30 00:00 |
03:55:46.49 |
+49:58:37.5 |
HIP 18282 |
17.65 |
| 2026-05-30 12:00 |
03:55:50.10 |
+49:58:47.8 |
HIP 18282 |
18.16 |
| 2026-05-31 00:00 |
03:55:53.70 |
+49:58:58.2 |
HIP 18282 |
18.68 |
| 2026-05-31 12:00 |
03:55:57.31 |
+49:59:08.7 |
HIP 18282 |
19.20 |
| 2026-06-01 00:00 |
03:56:00.90 |
+49:59:19.4 |
HIP 18282 |
19.73 |
| 2026-06-01 12:00 |
03:56:04.50 |
+49:59:30.2 |
HIP 18282 |
20.26 |
| 2026-06-02 00:00 |
03:56:08.08 |
+49:59:41.2 |
HIP 18282 |
20.80 |