| Parameter |
Value |
| Designation |
C/1998 M3 (Larsen) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-07-17T02:37:10.369920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:53Z |
| Obs used |
109 |
| NEO |
- |
| M1 |
6.500 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1998-08-29.0000000 |
| e |
1.00229380 |
| q (au) |
5.768232 |
| a (au) |
-2514.702905 |
| i (deg) |
113.422897 |
| Ω (om, deg) |
255.526698 |
| ω (w, deg) |
20.838100 |
| M (ma, deg) |
0.000335 |
Magnitude
Scatter + Global Linear
$$
M_a = (2.191 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
2.191 |
| n |
6.000 |
| gf |
0.933 |
| gb |
-0.858 |
| k |
1.000 |
| δ90 |
9.451 |
| 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 |
05:27:30.67 |
+41:32:59.0 |
HIP 25773 |
34.42 |
| 2026-06-01 12:00 |
05:27:33.78 |
+41:32:55.9 |
HIP 25773 |
33.88 |
| 2026-06-02 00:00 |
05:27:36.90 |
+41:32:52.8 |
HIP 25773 |
33.34 |
| 2026-06-02 12:00 |
05:27:40.02 |
+41:32:49.9 |
HIP 25773 |
32.80 |
| 2026-06-03 00:00 |
05:27:43.14 |
+41:32:47.1 |
HIP 25773 |
32.27 |
| 2026-06-03 12:00 |
05:27:46.27 |
+41:32:44.4 |
HIP 25773 |
31.74 |
| 2026-06-04 00:00 |
05:27:49.41 |
+41:32:41.7 |
HIP 25773 |
31.21 |
| 2026-06-04 12:00 |
05:27:52.54 |
+41:32:39.2 |
HIP 25773 |
30.68 |
| 2026-06-05 00:00 |
05:27:55.69 |
+41:32:36.8 |
HIP 25773 |
30.15 |
| 2026-06-05 12:00 |
05:27:58.83 |
+41:32:34.4 |
HIP 25773 |
29.63 |
| 2026-06-06 00:00 |
05:28:01.98 |
+41:32:32.1 |
HIP 25773 |
29.11 |
| 2026-06-06 12:00 |
05:28:05.13 |
+41:32:30.0 |
HIP 25773 |
28.59 |
| 2026-06-07 00:00 |
05:28:08.29 |
+41:32:27.9 |
HIP 25773 |
28.08 |
| 2026-06-07 12:00 |
05:28:11.45 |
+41:32:25.9 |
HIP 25773 |
27.57 |
| 2026-06-08 00:00 |
05:28:14.61 |
+41:32:24.1 |
HIP 25773 |
27.06 |
| 2026-06-08 12:00 |
05:28:17.77 |
+41:32:22.3 |
HIP 25773 |
26.56 |
| 2026-06-09 00:00 |
05:28:20.94 |
+41:32:20.6 |
HIP 25773 |
26.06 |
| 2026-06-09 12:00 |
05:28:24.11 |
+41:32:19.0 |
HIP 25773 |
25.57 |
| 2026-06-10 00:00 |
05:28:27.28 |
+41:32:17.5 |
HIP 25773 |
25.08 |
| 2026-06-10 12:00 |
05:28:30.45 |
+41:32:16.1 |
HIP 25773 |
24.60 |
| 2026-06-11 00:00 |
05:28:33.63 |
+41:32:14.7 |
HIP 25773 |
24.12 |
| 2026-06-11 12:00 |
05:28:36.80 |
+41:32:13.5 |
HIP 25773 |
23.65 |
| 2026-06-12 00:00 |
05:28:39.98 |
+41:32:12.4 |
HIP 25773 |
23.19 |
| 2026-06-12 12:00 |
05:28:43.16 |
+41:32:11.3 |
HIP 25773 |
22.73 |
| 2026-06-13 00:00 |
05:28:46.33 |
+41:32:10.4 |
HIP 25773 |
22.28 |
| 2026-06-13 12:00 |
05:28:49.51 |
+41:32:09.5 |
HIP 25773 |
21.84 |
| 2026-06-14 00:00 |
05:28:52.69 |
+41:32:08.8 |
HIP 25773 |
21.41 |
| 2026-06-14 12:00 |
05:28:55.87 |
+41:32:08.1 |
HIP 25773 |
20.98 |
| 2026-06-15 00:00 |
05:28:59.04 |
+41:32:07.5 |
HIP 25773 |
20.57 |
| 2026-06-15 12:00 |
05:29:02.22 |
+41:32:07.0 |
HIP 25773 |
20.17 |
| 2026-06-16 00:00 |
05:29:05.40 |
+41:32:06.6 |
HIP 25773 |
19.77 |
| 2026-06-16 12:00 |
05:29:08.57 |
+41:32:06.3 |
HIP 25816 |
19.24 |
| 2026-06-17 00:00 |
05:29:11.75 |
+41:32:06.1 |
HIP 25816 |
18.66 |
| 2026-06-17 12:00 |
05:29:14.92 |
+41:32:06.0 |
HIP 25816 |
18.09 |
| 2026-06-18 00:00 |
05:29:18.09 |
+41:32:06.0 |
HIP 25816 |
17.51 |
| 2026-06-18 12:00 |
05:29:21.26 |
+41:32:06.1 |
HIP 25816 |
16.94 |
| 2026-06-19 00:00 |
05:29:24.43 |
+41:32:06.2 |
HIP 25816 |
16.37 |
| 2026-06-19 12:00 |
05:29:27.59 |
+41:32:06.5 |
HIP 25816 |
15.80 |
| 2026-06-20 00:00 |
05:29:30.75 |
+41:32:06.8 |
HIP 25816 |
15.23 |
| 2026-06-20 12:00 |
05:29:33.91 |
+41:32:07.2 |
HIP 25816 |
14.67 |
| 2026-06-21 00:00 |
05:29:37.07 |
+41:32:07.7 |
HIP 25816 |
14.11 |
| 2026-06-21 12:00 |
05:29:40.22 |
+41:32:08.4 |
HIP 25816 |
13.55 |
| 2026-06-22 00:00 |
05:29:43.37 |
+41:32:09.1 |
HIP 25816 |
13.00 |