| Parameter |
Value |
| Designation |
C/1998 M5 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1999-01-24T13:39:13.763520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:54Z |
| Obs used |
1238 |
| NEO |
- |
| M1 |
9.500 |
| K1 |
5.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1998-11-27.0000000 |
| e |
0.99602466 |
| q (au) |
1.742289 |
| a (au) |
438.273933 |
| i (deg) |
82.228882 |
| Ω (om, deg) |
333.376703 |
| ω (w, deg) |
101.282943 |
| M (ma, deg) |
359.993709 |
Magnitude
Scatter + Global Linear
$$
M_a = (4.498 + 5.665\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
4.498 |
| n |
5.665 |
| gf |
1.000 |
| gb |
-0.954 |
| k |
0.996 |
| 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 |
07:56:56.92 |
-65:04:17.7 |
HIP 38605 |
18.87 |
| 2026-06-01 12:00 |
07:57:00.60 |
-65:03:52.9 |
HIP 38605 |
19.06 |
| 2026-06-02 00:00 |
07:57:04.31 |
-65:03:28.3 |
HIP 38605 |
19.27 |
| 2026-06-02 12:00 |
07:57:08.05 |
-65:03:04.0 |
HIP 38605 |
19.50 |
| 2026-06-03 00:00 |
07:57:11.82 |
-65:02:39.8 |
HIP 38605 |
19.75 |
| 2026-06-03 12:00 |
07:57:15.62 |
-65:02:15.8 |
HIP 38605 |
20.02 |
| 2026-06-04 00:00 |
07:57:19.45 |
-65:01:52.1 |
HIP 38605 |
20.30 |
| 2026-06-04 12:00 |
07:57:23.32 |
-65:01:28.6 |
HIP 38605 |
20.60 |
| 2026-06-05 00:00 |
07:57:27.21 |
-65:01:05.2 |
HIP 38605 |
20.91 |
| 2026-06-05 12:00 |
07:57:31.13 |
-65:00:42.2 |
HIP 39146 |
20.90 |
| 2026-06-06 00:00 |
07:57:35.09 |
-65:00:19.3 |
HIP 39146 |
20.35 |
| 2026-06-06 12:00 |
07:57:39.07 |
-64:59:56.6 |
HIP 39146 |
19.80 |
| 2026-06-07 00:00 |
07:57:43.08 |
-64:59:34.2 |
HIP 39146 |
19.25 |
| 2026-06-07 12:00 |
07:57:47.12 |
-64:59:12.0 |
HIP 39146 |
18.70 |
| 2026-06-08 00:00 |
07:57:51.19 |
-64:58:50.0 |
HIP 39146 |
18.15 |
| 2026-06-08 12:00 |
07:57:55.29 |
-64:58:28.3 |
HIP 39146 |
17.60 |
| 2026-06-09 00:00 |
07:57:59.42 |
-64:58:06.8 |
HIP 39146 |
17.05 |
| 2026-06-09 12:00 |
07:58:03.57 |
-64:57:45.5 |
HIP 39146 |
16.50 |
| 2026-06-10 00:00 |
07:58:07.75 |
-64:57:24.5 |
HIP 39146 |
15.95 |
| 2026-06-10 12:00 |
07:58:11.96 |
-64:57:03.7 |
HIP 39146 |
15.40 |
| 2026-06-11 00:00 |
07:58:16.20 |
-64:56:43.1 |
HIP 39146 |
14.85 |
| 2026-06-11 12:00 |
07:58:20.46 |
-64:56:22.8 |
HIP 39146 |
14.30 |
| 2026-06-12 00:00 |
07:58:24.75 |
-64:56:02.7 |
HIP 39146 |
13.75 |
| 2026-06-12 12:00 |
07:58:29.07 |
-64:55:42.8 |
HIP 39146 |
13.20 |
| 2026-06-13 00:00 |
07:58:33.41 |
-64:55:23.2 |
HIP 39146 |
12.65 |
| 2026-06-13 12:00 |
07:58:37.77 |
-64:55:03.8 |
HIP 39146 |
12.10 |
| 2026-06-14 00:00 |
07:58:42.16 |
-64:54:44.7 |
HIP 39146 |
11.56 |
| 2026-06-14 12:00 |
07:58:46.58 |
-64:54:25.8 |
HIP 39146 |
11.01 |
| 2026-06-15 00:00 |
07:58:51.02 |
-64:54:07.2 |
HIP 39146 |
10.46 |
| 2026-06-15 12:00 |
07:58:55.49 |
-64:53:48.8 |
HIP 39146 |
9.91 |
| 2026-06-16 00:00 |
07:58:59.97 |
-64:53:30.7 |
HIP 39146 |
9.36 |
| 2026-06-16 12:00 |
07:59:04.49 |
-64:53:12.8 |
HIP 39146 |
8.82 |
| 2026-06-17 00:00 |
07:59:09.02 |
-64:52:55.2 |
HIP 39146 |
8.27 |
| 2026-06-17 12:00 |
07:59:13.58 |
-64:52:37.8 |
HIP 39146 |
7.73 |
| 2026-06-18 00:00 |
07:59:18.16 |
-64:52:20.7 |
HIP 39146 |
7.19 |
| 2026-06-18 12:00 |
07:59:22.76 |
-64:52:03.8 |
HIP 39146 |
6.65 |
| 2026-06-19 00:00 |
07:59:27.38 |
-64:51:47.2 |
HIP 39146 |
6.11 |
| 2026-06-19 12:00 |
07:59:32.03 |
-64:51:30.9 |
HIP 39146 |
5.57 |
| 2026-06-20 00:00 |
07:59:36.69 |
-64:51:14.8 |
HIP 39146 |
5.04 |
| 2026-06-20 12:00 |
07:59:41.38 |
-64:50:59.0 |
HIP 39146 |
4.52 |
| 2026-06-21 00:00 |
07:59:46.08 |
-64:50:43.4 |
HIP 39146 |
4.01 |
| 2026-06-21 12:00 |
07:59:50.81 |
-64:50:28.1 |
HIP 39146 |
3.50 |
| 2026-06-22 00:00 |
07:59:55.56 |
-64:50:13.1 |
HIP 39146 |
3.02 |