C/1998 M2 (LINEAR)
| 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) |
| 2026-02-03 00:00 |
05:39:48.35 |
+14:17:54.3 |
HIP 26590 |
18.38 |
| 2026-02-03 12:00 |
05:39:46.69 |
+14:17:56.4 |
HIP 26590 |
18.14 |
| 2026-02-04 00:00 |
05:39:45.04 |
+14:17:58.5 |
HIP 26590 |
17.91 |
| 2026-02-04 12:00 |
05:39:43.42 |
+14:18:00.6 |
HIP 26590 |
17.68 |
| 2026-02-05 00:00 |
05:39:41.81 |
+14:18:02.8 |
HIP 26590 |
17.46 |
| 2026-02-05 12:00 |
05:39:40.22 |
+14:18:05.0 |
HIP 26590 |
17.25 |
| 2026-02-06 00:00 |
05:39:38.65 |
+14:18:07.2 |
HIP 26590 |
17.04 |
| 2026-02-06 12:00 |
05:39:37.09 |
+14:18:09.5 |
HIP 26590 |
16.84 |
| 2026-02-07 00:00 |
05:39:35.56 |
+14:18:11.9 |
HIP 26590 |
16.65 |
| 2026-02-07 12:00 |
05:39:34.04 |
+14:18:14.2 |
HIP 26590 |
16.47 |
| 2026-02-08 00:00 |
05:39:32.54 |
+14:18:16.7 |
HIP 26590 |
16.29 |
| 2026-02-08 12:00 |
05:39:31.06 |
+14:18:19.1 |
HIP 26590 |
16.13 |
| 2026-02-09 00:00 |
05:39:29.60 |
+14:18:21.6 |
HIP 26590 |
15.97 |
| 2026-02-09 12:00 |
05:39:28.16 |
+14:18:24.1 |
HIP 26590 |
15.81 |
| 2026-02-10 00:00 |
05:39:26.73 |
+14:18:26.7 |
HIP 26590 |
15.67 |
| 2026-02-10 12:00 |
05:39:25.33 |
+14:18:29.3 |
HIP 26590 |
15.53 |
| 2026-02-11 00:00 |
05:39:23.94 |
+14:18:31.9 |
HIP 26590 |
15.39 |
| 2026-02-11 12:00 |
05:39:22.58 |
+14:18:34.6 |
HIP 26590 |
15.27 |
| 2026-02-12 00:00 |
05:39:21.23 |
+14:18:37.3 |
HIP 26590 |
15.15 |
| 2026-02-12 12:00 |
05:39:19.91 |
+14:18:40.1 |
HIP 26590 |
15.04 |
| 2026-02-13 00:00 |
05:39:18.60 |
+14:18:42.9 |
HIP 26590 |
14.93 |
| 2026-02-13 12:00 |
05:39:17.31 |
+14:18:45.7 |
HIP 26590 |
14.83 |
| 2026-02-14 00:00 |
05:39:16.04 |
+14:18:48.6 |
HIP 26590 |
14.74 |
| 2026-02-14 12:00 |
05:39:14.80 |
+14:18:51.5 |
HIP 26590 |
14.65 |
| 2026-02-15 00:00 |
05:39:13.57 |
+14:18:54.4 |
HIP 26590 |
14.57 |
| 2026-02-15 12:00 |
05:39:12.36 |
+14:18:57.4 |
HIP 26590 |
14.50 |
| 2026-02-16 00:00 |
05:39:11.18 |
+14:19:00.4 |
HIP 26590 |
14.43 |
| 2026-02-16 12:00 |
05:39:10.01 |
+14:19:03.4 |
HIP 26590 |
14.36 |
| 2026-02-17 00:00 |
05:39:08.86 |
+14:19:06.4 |
HIP 26590 |
14.30 |
| 2026-02-17 12:00 |
05:39:07.74 |
+14:19:09.5 |
HIP 26590 |
14.25 |
| 2026-02-18 00:00 |
05:39:06.63 |
+14:19:12.7 |
HIP 26590 |
14.20 |
| 2026-02-18 12:00 |
05:39:05.55 |
+14:19:15.8 |
HIP 26590 |
14.15 |
| 2026-02-19 00:00 |
05:39:04.49 |
+14:19:19.0 |
HIP 26590 |
14.11 |
| 2026-02-19 12:00 |
05:39:03.44 |
+14:19:22.3 |
HIP 26590 |
14.07 |
| 2026-02-20 00:00 |
05:39:02.42 |
+14:19:25.5 |
HIP 26590 |
14.04 |
| 2026-02-20 12:00 |
05:39:01.42 |
+14:19:28.8 |
HIP 26590 |
14.00 |
| 2026-02-21 00:00 |
05:39:00.44 |
+14:19:32.1 |
HIP 26590 |
13.98 |
| 2026-02-21 12:00 |
05:38:59.48 |
+14:19:35.4 |
HIP 26590 |
13.95 |
| 2026-02-22 00:00 |
05:38:58.55 |
+14:19:38.8 |
HIP 26590 |
13.93 |
| 2026-02-22 12:00 |
05:38:57.63 |
+14:19:42.2 |
HIP 26590 |
13.91 |
| 2026-02-23 00:00 |
05:38:56.74 |
+14:19:45.6 |
HIP 26590 |
13.89 |
| 2026-02-23 12:00 |
05:38:55.86 |
+14:19:49.1 |
HIP 26590 |
13.88 |
| 2026-02-24 00:00 |
05:38:55.01 |
+14:19:52.6 |
HIP 26590 |
13.87 |