| Parameter |
Value |
| Designation |
C/1999 J4 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1999-11-17T10:01:47.156160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:00Z |
| Obs used |
40 |
| NEO |
- |
| M1 |
8.500 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1999-05-20.0000000 |
| e |
0.99971322 |
| q (au) |
3.781074 |
| a (au) |
13184.435879 |
| i (deg) |
118.909155 |
| Ω (om, deg) |
264.479748 |
| ω (w, deg) |
95.116153 |
| M (ma, deg) |
359.999882 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.599 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.599 |
| n |
6.000 |
| gf |
0.980 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
9.996 |
| 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) |
| 2026-03-26 00:00 |
03:38:46.29 |
-32:24:14.4 |
HIP 16993 |
3.10 |
| 2026-03-26 12:00 |
03:38:47.99 |
-32:23:49.2 |
HIP 16993 |
3.27 |
| 2026-03-27 00:00 |
03:38:49.71 |
-32:23:24.2 |
HIP 16993 |
3.53 |
| 2026-03-27 12:00 |
03:38:51.45 |
-32:22:59.3 |
HIP 16993 |
3.85 |
| 2026-03-28 00:00 |
03:38:53.21 |
-32:22:34.6 |
HIP 16993 |
4.22 |
| 2026-03-28 12:00 |
03:38:54.99 |
-32:22:10.0 |
HIP 16993 |
4.63 |
| 2026-03-29 00:00 |
03:38:56.78 |
-32:21:45.5 |
HIP 16993 |
5.07 |
| 2026-03-29 12:00 |
03:38:58.59 |
-32:21:21.1 |
HIP 16993 |
5.54 |
| 2026-03-30 00:00 |
03:39:00.42 |
-32:20:56.9 |
HIP 16993 |
6.03 |
| 2026-03-30 12:00 |
03:39:02.27 |
-32:20:32.9 |
HIP 16993 |
6.53 |
| 2026-03-31 00:00 |
03:39:04.14 |
-32:20:09.0 |
HIP 16993 |
7.04 |
| 2026-03-31 12:00 |
03:39:06.02 |
-32:19:45.2 |
HIP 16993 |
7.56 |
| 2026-04-01 00:00 |
03:39:07.93 |
-32:19:21.5 |
HIP 16993 |
8.09 |
| 2026-04-01 12:00 |
03:39:09.85 |
-32:18:58.1 |
HIP 16993 |
8.63 |
| 2026-04-02 00:00 |
03:39:11.78 |
-32:18:34.7 |
HIP 16993 |
9.17 |
| 2026-04-02 12:00 |
03:39:13.74 |
-32:18:11.6 |
HIP 16993 |
9.71 |
| 2026-04-03 00:00 |
03:39:15.71 |
-32:17:48.5 |
HIP 16993 |
10.26 |
| 2026-04-03 12:00 |
03:39:17.69 |
-32:17:25.6 |
HIP 16993 |
10.82 |
| 2026-04-04 00:00 |
03:39:19.70 |
-32:17:02.9 |
HIP 16993 |
11.37 |
| 2026-04-04 12:00 |
03:39:21.72 |
-32:16:40.4 |
HIP 16993 |
11.93 |
| 2026-04-05 00:00 |
03:39:23.76 |
-32:16:18.0 |
HIP 16993 |
12.49 |
| 2026-04-05 12:00 |
03:39:25.81 |
-32:15:55.7 |
HIP 16993 |
13.06 |
| 2026-04-06 00:00 |
03:39:27.88 |
-32:15:33.6 |
HIP 16993 |
13.62 |
| 2026-04-06 12:00 |
03:39:29.96 |
-32:15:11.7 |
HIP 16993 |
14.19 |
| 2026-04-07 00:00 |
03:39:32.07 |
-32:14:49.9 |
HIP 16993 |
14.76 |
| 2026-04-07 12:00 |
03:39:34.18 |
-32:14:28.3 |
HIP 16993 |
15.33 |
| 2026-04-08 00:00 |
03:39:36.31 |
-32:14:06.9 |
HIP 16993 |
15.90 |
| 2026-04-08 12:00 |
03:39:38.46 |
-32:13:45.7 |
HIP 16993 |
16.48 |
| 2026-04-09 00:00 |
03:39:40.62 |
-32:13:24.6 |
HIP 16993 |
17.05 |
| 2026-04-09 12:00 |
03:39:42.80 |
-32:13:03.7 |
HIP 17198 |
17.08 |
| 2026-04-10 00:00 |
03:39:44.99 |
-32:12:42.9 |
HIP 17198 |
16.52 |
| 2026-04-10 12:00 |
03:39:47.20 |
-32:12:22.3 |
HIP 17198 |
15.96 |
| 2026-04-11 00:00 |
03:39:49.42 |
-32:12:02.0 |
HIP 17198 |
15.39 |
| 2026-04-11 12:00 |
03:39:51.66 |
-32:11:41.7 |
HIP 17198 |
14.83 |
| 2026-04-12 00:00 |
03:39:53.91 |
-32:11:21.7 |
HIP 17198 |
14.26 |
| 2026-04-12 12:00 |
03:39:56.17 |
-32:11:01.9 |
HIP 17198 |
13.70 |
| 2026-04-13 00:00 |
03:39:58.45 |
-32:10:42.2 |
HIP 17198 |
13.13 |
| 2026-04-13 12:00 |
03:40:00.74 |
-32:10:22.7 |
HIP 17198 |
12.57 |
| 2026-04-14 00:00 |
03:40:03.04 |
-32:10:03.4 |
HIP 17198 |
12.00 |
| 2026-04-14 12:00 |
03:40:05.36 |
-32:09:44.3 |
HIP 17198 |
11.43 |
| 2026-04-15 00:00 |
03:40:07.69 |
-32:09:25.4 |
HIP 17198 |
10.87 |
| 2026-04-15 12:00 |
03:40:10.04 |
-32:09:06.6 |
HIP 17198 |
10.30 |
| 2026-04-16 00:00 |
03:40:12.40 |
-32:08:48.1 |
HIP 17198 |
9.74 |