| Parameter |
Value |
| Designation |
C/1999 H3 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1999-08-18T05:16:31.920960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:59Z |
| Obs used |
847 |
| NEO |
- |
| M1 |
10.300 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2000-02-08.0000000 |
| e |
1.00296415 |
| q (au) |
3.500834 |
| a (au) |
-1181.056590 |
| i (deg) |
115.837319 |
| Ω (om, deg) |
332.729392 |
| ω (w, deg) |
101.910427 |
| M (ma, deg) |
0.004220 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.667 + 4.199\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.667 |
| n |
4.199 |
| gf |
0.907 |
| gb |
-0.935 |
| k |
1.000 |
| δ90 |
1.000 |
| 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) |
| 2026-07-29 00:00 |
06:34:05.87 |
-33:52:36.3 |
HIP 31374 |
11.13 |
| 2026-07-29 12:00 |
06:34:08.30 |
-33:52:53.1 |
HIP 31374 |
10.58 |
| 2026-07-30 00:00 |
06:34:10.72 |
-33:53:10.0 |
HIP 31374 |
10.03 |
| 2026-07-30 12:00 |
06:34:13.12 |
-33:53:27.2 |
HIP 31374 |
9.49 |
| 2026-07-31 00:00 |
06:34:15.51 |
-33:53:44.5 |
HIP 31374 |
8.94 |
| 2026-07-31 12:00 |
06:34:17.89 |
-33:54:02.1 |
HIP 31374 |
8.40 |
| 2026-08-01 00:00 |
06:34:20.26 |
-33:54:19.9 |
HIP 31374 |
7.86 |
| 2026-08-01 12:00 |
06:34:22.62 |
-33:54:38.0 |
HIP 31374 |
7.33 |
| 2026-08-02 00:00 |
06:34:24.96 |
-33:54:56.2 |
HIP 31374 |
6.80 |
| 2026-08-02 12:00 |
06:34:27.30 |
-33:55:14.7 |
HIP 31374 |
6.28 |
| 2026-08-03 00:00 |
06:34:29.61 |
-33:55:33.3 |
HIP 31374 |
5.77 |
| 2026-08-03 12:00 |
06:34:31.92 |
-33:55:52.2 |
HIP 31374 |
5.26 |
| 2026-08-04 00:00 |
06:34:34.21 |
-33:56:11.3 |
HIP 31374 |
4.77 |
| 2026-08-04 12:00 |
06:34:36.49 |
-33:56:30.6 |
HIP 31374 |
4.30 |
| 2026-08-05 00:00 |
06:34:38.76 |
-33:56:50.1 |
HIP 31374 |
3.85 |
| 2026-08-05 12:00 |
06:34:41.01 |
-33:57:09.8 |
HIP 31374 |
3.44 |
| 2026-08-06 00:00 |
06:34:43.25 |
-33:57:29.7 |
HIP 31374 |
3.07 |
| 2026-08-06 12:00 |
06:34:45.48 |
-33:57:49.9 |
HIP 31374 |
2.77 |
| 2026-08-07 00:00 |
06:34:47.69 |
-33:58:10.2 |
HIP 31374 |
2.56 |
| 2026-08-07 12:00 |
06:34:49.89 |
-33:58:30.8 |
HIP 31374 |
2.46 |
| 2026-08-08 00:00 |
06:34:52.07 |
-33:58:51.5 |
HIP 31374 |
2.49 |
| 2026-08-08 12:00 |
06:34:54.24 |
-33:59:12.4 |
HIP 31374 |
2.63 |
| 2026-08-09 00:00 |
06:34:56.39 |
-33:59:33.6 |
HIP 31374 |
2.88 |
| 2026-08-09 12:00 |
06:34:58.53 |
-33:59:54.9 |
HIP 31374 |
3.21 |
| 2026-08-10 00:00 |
06:35:00.65 |
-34:00:16.5 |
HIP 31374 |
3.59 |
| 2026-08-10 12:00 |
06:35:02.76 |
-34:00:38.2 |
HIP 31374 |
4.02 |
| 2026-08-11 00:00 |
06:35:04.85 |
-34:01:00.2 |
HIP 31374 |
4.47 |
| 2026-08-11 12:00 |
06:35:06.93 |
-34:01:22.3 |
HIP 31374 |
4.95 |
| 2026-08-12 00:00 |
06:35:08.99 |
-34:01:44.6 |
HIP 31374 |
5.44 |
| 2026-08-12 12:00 |
06:35:11.03 |
-34:02:07.1 |
HIP 31374 |
5.94 |
| 2026-08-13 00:00 |
06:35:13.06 |
-34:02:29.8 |
HIP 31374 |
6.45 |
| 2026-08-13 12:00 |
06:35:15.07 |
-34:02:52.7 |
HIP 31374 |
6.96 |
| 2026-08-14 00:00 |
06:35:17.07 |
-34:03:15.8 |
HIP 31374 |
7.49 |
| 2026-08-14 12:00 |
06:35:19.05 |
-34:03:39.1 |
HIP 31374 |
8.01 |
| 2026-08-15 00:00 |
06:35:21.01 |
-34:04:02.5 |
HIP 31374 |
8.54 |
| 2026-08-15 12:00 |
06:35:22.96 |
-34:04:26.1 |
HIP 31374 |
9.07 |
| 2026-08-16 00:00 |
06:35:24.88 |
-34:04:49.9 |
HIP 31374 |
9.60 |
| 2026-08-16 12:00 |
06:35:26.79 |
-34:05:13.9 |
HIP 31374 |
10.13 |
| 2026-08-17 00:00 |
06:35:28.69 |
-34:05:38.1 |
HIP 31374 |
10.67 |
| 2026-08-17 12:00 |
06:35:30.56 |
-34:06:02.4 |
HIP 31374 |
11.20 |
| 2026-08-18 00:00 |
06:35:32.42 |
-34:06:26.9 |
HIP 31374 |
11.74 |
| 2026-08-18 12:00 |
06:35:34.26 |
-34:06:51.6 |
HIP 31374 |
12.28 |
| 2026-08-19 00:00 |
06:35:36.08 |
-34:07:16.5 |
HIP 31374 |
12.81 |