C/1998 M1 (LINEAR)
| Parameter |
Value |
| Designation |
C/1998 M1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-10-28T02:41:20.860800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:53Z |
| Obs used |
191 |
| NEO |
- |
| M1 |
6.500 |
| K1 |
14.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1998-09-21.0000000 |
| e |
0.99276578 |
| q (au) |
3.118124 |
| a (au) |
431.024098 |
| i (deg) |
20.384564 |
| Ω (om, deg) |
256.067464 |
| ω (w, deg) |
19.403420 |
| M (ma, deg) |
359.995912 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.198 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.198 |
| n |
6.000 |
| gf |
0.986 |
| gb |
-0.501 |
| k |
1.000 |
| δ90 |
9.999 |
| 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 |
04:14:23.52 |
+24:32:31.6 |
HIP 19829 |
16.98 |
| 2026-02-03 12:00 |
04:14:22.65 |
+24:32:26.7 |
HIP 19829 |
17.03 |
| 2026-02-04 00:00 |
04:14:21.79 |
+24:32:21.8 |
HIP 19829 |
17.08 |
| 2026-02-04 12:00 |
04:14:20.95 |
+24:32:17.0 |
HIP 19829 |
17.13 |
| 2026-02-05 00:00 |
04:14:20.14 |
+24:32:12.2 |
HIP 19829 |
17.18 |
| 2026-02-05 12:00 |
04:14:19.36 |
+24:32:07.5 |
HIP 19829 |
17.23 |
| 2026-02-06 00:00 |
04:14:18.59 |
+24:32:02.8 |
HIP 19829 |
17.28 |
| 2026-02-06 12:00 |
04:14:17.85 |
+24:31:58.2 |
HIP 19829 |
17.32 |
| 2026-02-07 00:00 |
04:14:17.13 |
+24:31:53.7 |
HIP 19829 |
17.37 |
| 2026-02-07 12:00 |
04:14:16.43 |
+24:31:49.2 |
HIP 19829 |
17.42 |
| 2026-02-08 00:00 |
04:14:15.76 |
+24:31:44.7 |
HIP 19829 |
17.46 |
| 2026-02-08 12:00 |
04:14:15.11 |
+24:31:40.3 |
HIP 19829 |
17.50 |
| 2026-02-09 00:00 |
04:14:14.49 |
+24:31:36.0 |
HIP 19829 |
17.54 |
| 2026-02-09 12:00 |
04:14:13.88 |
+24:31:31.7 |
HIP 19829 |
17.58 |
| 2026-02-10 00:00 |
04:14:13.30 |
+24:31:27.4 |
HIP 19829 |
17.62 |
| 2026-02-10 12:00 |
04:14:12.75 |
+24:31:23.2 |
HIP 19829 |
17.66 |
| 2026-02-11 00:00 |
04:14:12.22 |
+24:31:19.1 |
HIP 19829 |
17.69 |
| 2026-02-11 12:00 |
04:14:11.71 |
+24:31:15.0 |
HIP 19829 |
17.72 |
| 2026-02-12 00:00 |
04:14:11.22 |
+24:31:11.0 |
HIP 19829 |
17.75 |
| 2026-02-12 12:00 |
04:14:10.76 |
+24:31:07.0 |
HIP 19829 |
17.78 |
| 2026-02-13 00:00 |
04:14:10.33 |
+24:31:03.1 |
HIP 19829 |
17.81 |
| 2026-02-13 12:00 |
04:14:09.91 |
+24:30:59.2 |
HIP 19829 |
17.83 |
| 2026-02-14 00:00 |
04:14:09.52 |
+24:30:55.4 |
HIP 19829 |
17.85 |
| 2026-02-14 12:00 |
04:14:09.16 |
+24:30:51.7 |
HIP 19829 |
17.87 |
| 2026-02-15 00:00 |
04:14:08.81 |
+24:30:48.0 |
HIP 19829 |
17.88 |
| 2026-02-15 12:00 |
04:14:08.49 |
+24:30:44.3 |
HIP 19829 |
17.90 |
| 2026-02-16 00:00 |
04:14:08.20 |
+24:30:40.8 |
HIP 19829 |
17.90 |
| 2026-02-16 12:00 |
04:14:07.93 |
+24:30:37.2 |
HIP 19829 |
17.91 |
| 2026-02-17 00:00 |
04:14:07.68 |
+24:30:33.8 |
HIP 19829 |
17.91 |
| 2026-02-17 12:00 |
04:14:07.46 |
+24:30:30.4 |
HIP 19829 |
17.91 |
| 2026-02-18 00:00 |
04:14:07.26 |
+24:30:27.0 |
HIP 19829 |
17.91 |
| 2026-02-18 12:00 |
04:14:07.09 |
+24:30:23.7 |
HIP 19829 |
17.90 |
| 2026-02-19 00:00 |
04:14:06.93 |
+24:30:20.5 |
HIP 19829 |
17.90 |
| 2026-02-19 12:00 |
04:14:06.81 |
+24:30:17.3 |
HIP 19829 |
17.88 |
| 2026-02-20 00:00 |
04:14:06.70 |
+24:30:14.2 |
HIP 19829 |
17.87 |
| 2026-02-20 12:00 |
04:14:06.62 |
+24:30:11.1 |
HIP 19829 |
17.85 |
| 2026-02-21 00:00 |
04:14:06.57 |
+24:30:08.1 |
HIP 19829 |
17.82 |
| 2026-02-21 12:00 |
04:14:06.54 |
+24:30:05.2 |
HIP 19829 |
17.80 |
| 2026-02-22 00:00 |
04:14:06.53 |
+24:30:02.3 |
HIP 19829 |
17.77 |
| 2026-02-22 12:00 |
04:14:06.55 |
+24:29:59.5 |
HIP 19829 |
17.74 |
| 2026-02-23 00:00 |
04:14:06.59 |
+24:29:56.7 |
HIP 19829 |
17.70 |
| 2026-02-23 12:00 |
04:14:06.65 |
+24:29:54.0 |
HIP 19829 |
17.66 |
| 2026-02-24 00:00 |
04:14:06.74 |
+24:29:51.4 |
HIP 19829 |
17.62 |