| Parameter |
Value |
| Designation |
C/1998 M2 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-08-13T04:08:09.286080Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:53Z |
| Obs used |
386 |
| NEO |
- |
| M1 |
8.300 |
| K1 |
11.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1998-08-18.0000000 |
| e |
0.99775644 |
| q (au) |
2.725333 |
| a (au) |
1214.736178 |
| i (deg) |
60.182314 |
| Ω (om, deg) |
260.880195 |
| ω (w, deg) |
37.242994 |
| M (ma, deg) |
0.000112 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.569 + 5.036\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.569 |
| n |
5.036 |
| 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) |
| 2026-09-20 00:00 |
05:48:46.70 |
+14:17:14.4 |
HIP 27504 |
23.88 |
| 2026-09-20 12:00 |
05:48:46.73 |
+14:17:07.2 |
HIP 27504 |
23.77 |
| 2026-09-21 00:00 |
05:48:46.74 |
+14:17:00.0 |
HIP 27504 |
23.66 |
| 2026-09-21 12:00 |
05:48:46.74 |
+14:16:52.7 |
HIP 27504 |
23.55 |
| 2026-09-22 00:00 |
05:48:46.71 |
+14:16:45.5 |
HIP 27504 |
23.44 |
| 2026-09-22 12:00 |
05:48:46.65 |
+14:16:38.2 |
HIP 27504 |
23.34 |
| 2026-09-23 00:00 |
05:48:46.58 |
+14:16:31.0 |
HIP 27504 |
23.23 |
| 2026-09-23 12:00 |
05:48:46.49 |
+14:16:23.7 |
HIP 27504 |
23.13 |
| 2026-09-24 00:00 |
05:48:46.37 |
+14:16:16.5 |
HIP 27504 |
23.03 |
| 2026-09-24 12:00 |
05:48:46.24 |
+14:16:09.2 |
HIP 27504 |
22.94 |
| 2026-09-25 00:00 |
05:48:46.08 |
+14:16:01.9 |
HIP 27504 |
22.84 |
| 2026-09-25 12:00 |
05:48:45.90 |
+14:15:54.7 |
HIP 27504 |
22.75 |
| 2026-09-26 00:00 |
05:48:45.70 |
+14:15:47.4 |
HIP 27504 |
22.66 |
| 2026-09-26 12:00 |
05:48:45.48 |
+14:15:40.1 |
HIP 27504 |
22.58 |
| 2026-09-27 00:00 |
05:48:45.23 |
+14:15:32.8 |
HIP 27504 |
22.49 |
| 2026-09-27 12:00 |
05:48:44.97 |
+14:15:25.5 |
HIP 27504 |
22.41 |
| 2026-09-28 00:00 |
05:48:44.69 |
+14:15:18.2 |
HIP 27504 |
22.33 |
| 2026-09-28 12:00 |
05:48:44.38 |
+14:15:11.0 |
HIP 27504 |
22.26 |
| 2026-09-29 00:00 |
05:48:44.05 |
+14:15:03.7 |
HIP 27504 |
22.19 |
| 2026-09-29 12:00 |
05:48:43.70 |
+14:14:56.4 |
HIP 27504 |
22.12 |
| 2026-09-30 00:00 |
05:48:43.33 |
+14:14:49.1 |
HIP 27504 |
22.05 |
| 2026-09-30 12:00 |
05:48:42.94 |
+14:14:41.8 |
HIP 27504 |
21.99 |
| 2026-10-01 00:00 |
05:48:42.53 |
+14:14:34.5 |
HIP 27504 |
21.93 |
| 2026-10-01 12:00 |
05:48:42.10 |
+14:14:27.2 |
HIP 27504 |
21.87 |
| 2026-10-02 00:00 |
05:48:41.64 |
+14:14:19.9 |
HIP 27504 |
21.82 |
| 2026-10-02 12:00 |
05:48:41.17 |
+14:14:12.6 |
HIP 27504 |
21.77 |
| 2026-10-03 00:00 |
05:48:40.67 |
+14:14:05.3 |
HIP 27504 |
21.72 |
| 2026-10-03 12:00 |
05:48:40.15 |
+14:13:58.0 |
HIP 27504 |
21.68 |
| 2026-10-04 00:00 |
05:48:39.61 |
+14:13:50.7 |
HIP 27504 |
21.65 |
| 2026-10-04 12:00 |
05:48:39.05 |
+14:13:43.4 |
HIP 27504 |
21.61 |
| 2026-10-05 00:00 |
05:48:38.47 |
+14:13:36.1 |
HIP 27504 |
21.58 |
| 2026-10-05 12:00 |
05:48:37.87 |
+14:13:28.9 |
HIP 27504 |
21.56 |
| 2026-10-06 00:00 |
05:48:37.24 |
+14:13:21.6 |
HIP 27504 |
21.54 |
| 2026-10-06 12:00 |
05:48:36.60 |
+14:13:14.3 |
HIP 27504 |
21.52 |
| 2026-10-07 00:00 |
05:48:35.93 |
+14:13:07.1 |
HIP 27504 |
21.51 |
| 2026-10-07 12:00 |
05:48:35.24 |
+14:12:59.8 |
HIP 27504 |
21.51 |
| 2026-10-08 00:00 |
05:48:34.54 |
+14:12:52.5 |
HIP 27504 |
21.51 |
| 2026-10-08 12:00 |
05:48:33.81 |
+14:12:45.3 |
HIP 27504 |
21.51 |
| 2026-10-09 00:00 |
05:48:33.06 |
+14:12:38.1 |
HIP 27504 |
21.52 |
| 2026-10-09 12:00 |
05:48:32.29 |
+14:12:30.8 |
HIP 27504 |
21.54 |
| 2026-10-10 00:00 |
05:48:31.50 |
+14:12:23.6 |
HIP 27504 |
21.56 |
| 2026-10-10 12:00 |
05:48:30.68 |
+14:12:16.4 |
HIP 27504 |
21.58 |
| 2026-10-11 00:00 |
05:48:29.85 |
+14:12:09.2 |
HIP 27364 |
21.45 |