| 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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
03:56:11.67 |
+49:59:52.2 |
HIP 18282 |
21.34 |
| 2026-06-03 00:00 |
03:56:15.24 |
+50:00:03.4 |
HIP 18282 |
21.89 |
| 2026-06-03 12:00 |
03:56:18.82 |
+50:00:14.8 |
HIP 18282 |
22.44 |
| 2026-06-04 00:00 |
03:56:22.38 |
+50:00:26.2 |
HIP 18282 |
22.99 |
| 2026-06-04 12:00 |
03:56:25.95 |
+50:00:37.8 |
HIP 18282 |
23.55 |
| 2026-06-05 00:00 |
03:56:29.50 |
+50:00:49.5 |
HIP 18282 |
24.11 |
| 2026-06-05 12:00 |
03:56:33.05 |
+50:01:01.3 |
HIP 18282 |
24.67 |
| 2026-06-06 00:00 |
03:56:36.59 |
+50:01:13.3 |
HIP 18282 |
25.24 |
| 2026-06-06 12:00 |
03:56:40.13 |
+50:01:25.4 |
HIP 18282 |
25.81 |
| 2026-06-07 00:00 |
03:56:43.66 |
+50:01:37.6 |
HIP 18282 |
26.38 |
| 2026-06-07 12:00 |
03:56:47.18 |
+50:01:49.9 |
HIP 18282 |
26.95 |
| 2026-06-08 00:00 |
03:56:50.69 |
+50:02:02.4 |
HIP 18282 |
27.52 |
| 2026-06-08 12:00 |
03:56:54.20 |
+50:02:15.0 |
HIP 18295 |
27.82 |
| 2026-06-09 00:00 |
03:56:57.70 |
+50:02:27.7 |
HIP 18295 |
28.10 |
| 2026-06-09 12:00 |
03:57:01.19 |
+50:02:40.5 |
HIP 18295 |
28.39 |
| 2026-06-10 00:00 |
03:57:04.67 |
+50:02:53.4 |
HIP 18295 |
28.69 |
| 2026-06-10 12:00 |
03:57:08.15 |
+50:03:06.5 |
HIP 18295 |
28.99 |
| 2026-06-11 00:00 |
03:57:11.61 |
+50:03:19.7 |
HIP 18295 |
29.30 |
| 2026-06-11 12:00 |
03:57:15.07 |
+50:03:33.0 |
HIP 18295 |
29.61 |
| 2026-06-12 00:00 |
03:57:18.52 |
+50:03:46.4 |
HIP 18295 |
29.94 |
| 2026-06-12 12:00 |
03:57:21.95 |
+50:04:00.0 |
HIP 18295 |
30.26 |
| 2026-06-13 00:00 |
03:57:25.38 |
+50:04:13.6 |
HIP 18295 |
30.60 |
| 2026-06-13 12:00 |
03:57:28.80 |
+50:04:27.3 |
HIP 18295 |
30.94 |
| 2026-06-14 00:00 |
03:57:32.21 |
+50:04:41.2 |
HIP 18295 |
31.28 |
| 2026-06-14 12:00 |
03:57:35.61 |
+50:04:55.2 |
HIP 18295 |
31.63 |
| 2026-06-15 00:00 |
03:57:38.99 |
+50:05:09.3 |
HIP 18295 |
31.98 |
| 2026-06-15 12:00 |
03:57:42.37 |
+50:05:23.5 |
HIP 18295 |
32.34 |
| 2026-06-16 00:00 |
03:57:45.73 |
+50:05:37.9 |
HIP 18295 |
32.70 |
| 2026-06-16 12:00 |
03:57:49.09 |
+50:05:52.3 |
HIP 18295 |
33.07 |
| 2026-06-17 00:00 |
03:57:52.43 |
+50:06:06.9 |
HIP 18295 |
33.44 |
| 2026-06-17 12:00 |
03:57:55.76 |
+50:06:21.5 |
HIP 18295 |
33.81 |
| 2026-06-18 00:00 |
03:57:59.08 |
+50:06:36.3 |
HIP 18295 |
34.19 |
| 2026-06-18 12:00 |
03:58:02.38 |
+50:06:51.2 |
HIP 18295 |
34.57 |
| 2026-06-19 00:00 |
03:58:05.67 |
+50:07:06.2 |
HIP 18295 |
34.95 |
| 2026-06-19 12:00 |
03:58:08.95 |
+50:07:21.3 |
HIP 18295 |
35.33 |
| 2026-06-20 00:00 |
03:58:12.22 |
+50:07:36.5 |
HIP 18295 |
35.72 |
| 2026-06-20 12:00 |
03:58:15.47 |
+50:07:51.8 |
HIP 18295 |
36.11 |
| 2026-06-21 00:00 |
03:58:18.71 |
+50:08:07.1 |
HIP 18295 |
36.51 |
| 2026-06-21 12:00 |
03:58:21.94 |
+50:08:22.6 |
HIP 18814 |
36.42 |
| 2026-06-22 00:00 |
03:58:25.15 |
+50:08:38.3 |
HIP 18814 |
36.03 |