C/1999 J4 (LINEAR)
| 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) |
| 2026-02-03 00:00 |
03:37:54.05 |
-33:11:59.6 |
HIP 16884 |
8.61 |
| 2026-02-03 12:00 |
03:37:53.28 |
-33:11:32.5 |
HIP 16884 |
8.68 |
| 2026-02-04 00:00 |
03:37:52.53 |
-33:11:05.3 |
HIP 16884 |
8.79 |
| 2026-02-04 12:00 |
03:37:51.81 |
-33:10:38.0 |
HIP 16884 |
8.92 |
| 2026-02-05 00:00 |
03:37:51.11 |
-33:10:10.6 |
HIP 16884 |
9.08 |
| 2026-02-05 12:00 |
03:37:50.44 |
-33:09:43.1 |
HIP 16884 |
9.27 |
| 2026-02-06 00:00 |
03:37:49.80 |
-33:09:15.6 |
HIP 16884 |
9.49 |
| 2026-02-06 12:00 |
03:37:49.18 |
-33:08:47.9 |
HIP 16884 |
9.73 |
| 2026-02-07 00:00 |
03:37:48.59 |
-33:08:20.2 |
HIP 16884 |
9.99 |
| 2026-02-07 12:00 |
03:37:48.03 |
-33:07:52.3 |
HIP 16884 |
10.27 |
| 2026-02-08 00:00 |
03:37:47.49 |
-33:07:24.4 |
HIP 16884 |
10.57 |
| 2026-02-08 12:00 |
03:37:46.98 |
-33:06:56.5 |
HIP 16884 |
10.89 |
| 2026-02-09 00:00 |
03:37:46.50 |
-33:06:28.4 |
HIP 16884 |
11.22 |
| 2026-02-09 12:00 |
03:37:46.04 |
-33:06:00.3 |
HIP 16884 |
11.57 |
| 2026-02-10 00:00 |
03:37:45.61 |
-33:05:32.1 |
HIP 16884 |
11.93 |
| 2026-02-10 12:00 |
03:37:45.20 |
-33:05:03.8 |
HIP 16884 |
12.30 |
| 2026-02-11 00:00 |
03:37:44.82 |
-33:04:35.5 |
HIP 16884 |
12.68 |
| 2026-02-11 12:00 |
03:37:44.47 |
-33:04:07.1 |
HIP 16884 |
13.07 |
| 2026-02-12 00:00 |
03:37:44.14 |
-33:03:38.7 |
HIP 16884 |
13.47 |
| 2026-02-12 12:00 |
03:37:43.84 |
-33:03:10.2 |
HIP 16884 |
13.88 |
| 2026-02-13 00:00 |
03:37:43.57 |
-33:02:41.6 |
HIP 16884 |
14.29 |
| 2026-02-13 12:00 |
03:37:43.32 |
-33:02:13.0 |
HIP 16884 |
14.72 |
| 2026-02-14 00:00 |
03:37:43.10 |
-33:01:44.3 |
HIP 16884 |
15.15 |
| 2026-02-14 12:00 |
03:37:42.91 |
-33:01:15.6 |
HIP 16884 |
15.58 |
| 2026-02-15 00:00 |
03:37:42.74 |
-33:00:46.8 |
HIP 16884 |
16.02 |
| 2026-02-15 12:00 |
03:37:42.60 |
-33:00:18.0 |
HIP 16946 |
16.42 |
| 2026-02-16 00:00 |
03:37:42.49 |
-32:59:49.2 |
HIP 16946 |
15.96 |
| 2026-02-16 12:00 |
03:37:42.40 |
-32:59:20.3 |
HIP 16946 |
15.51 |
| 2026-02-17 00:00 |
03:37:42.34 |
-32:58:51.3 |
HIP 16946 |
15.05 |
| 2026-02-17 12:00 |
03:37:42.30 |
-32:58:22.4 |
HIP 16946 |
14.59 |
| 2026-02-18 00:00 |
03:37:42.29 |
-32:57:53.4 |
HIP 16946 |
14.13 |
| 2026-02-18 12:00 |
03:37:42.31 |
-32:57:24.4 |
HIP 16946 |
13.67 |
| 2026-02-19 00:00 |
03:37:42.36 |
-32:56:55.3 |
HIP 16946 |
13.21 |
| 2026-02-19 12:00 |
03:37:42.43 |
-32:56:26.3 |
HIP 16946 |
12.75 |
| 2026-02-20 00:00 |
03:37:42.52 |
-32:55:57.2 |
HIP 16946 |
12.29 |
| 2026-02-20 12:00 |
03:37:42.64 |
-32:55:28.1 |
HIP 16946 |
11.83 |
| 2026-02-21 00:00 |
03:37:42.79 |
-32:54:58.9 |
HIP 16946 |
11.37 |
| 2026-02-21 12:00 |
03:37:42.97 |
-32:54:29.8 |
HIP 16946 |
10.91 |
| 2026-02-22 00:00 |
03:37:43.17 |
-32:54:00.7 |
HIP 16946 |
10.44 |
| 2026-02-22 12:00 |
03:37:43.39 |
-32:53:31.5 |
HIP 16946 |
9.98 |
| 2026-02-23 00:00 |
03:37:43.65 |
-32:53:02.3 |
HIP 16946 |
9.52 |
| 2026-02-23 12:00 |
03:37:43.92 |
-32:52:33.2 |
HIP 16946 |
9.06 |
| 2026-02-24 00:00 |
03:37:44.23 |
-32:52:04.0 |
HIP 16946 |
8.60 |