| Parameter |
Value |
| Designation |
C/1999 L3 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2000-01-04T21:48:00.221760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:00Z |
| Obs used |
340 |
| NEO |
- |
| M1 |
8.300 |
| K1 |
15.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1999-12-24.0000000 |
| e |
0.97436453 |
| q (au) |
1.988918 |
| a (au) |
77.584594 |
| i (deg) |
166.099275 |
| Ω (om, deg) |
140.161317 |
| ω (w, deg) |
353.297874 |
| M (ma, deg) |
359.982825 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.988 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.988 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.905 |
| k |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1999-06-09 |
2000-01-04 |
+8.4713 |
-3.326 |
| 2000-01-05 |
2000-04-23 |
-5.4078 |
+1.574 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
23:00:34.27 |
+00:33:28.7 |
HIP 113610 |
22.35 |
| 2026-09-20 12:00 |
23:00:31.78 |
+00:33:11.6 |
HIP 113610 |
22.10 |
| 2026-09-21 00:00 |
23:00:29.29 |
+00:32:54.5 |
HIP 113610 |
21.86 |
| 2026-09-21 12:00 |
23:00:26.81 |
+00:32:37.5 |
HIP 113610 |
21.65 |
| 2026-09-22 00:00 |
23:00:24.33 |
+00:32:20.4 |
HIP 113610 |
21.46 |
| 2026-09-22 12:00 |
23:00:21.86 |
+00:32:03.3 |
HIP 113610 |
21.28 |
| 2026-09-23 00:00 |
23:00:19.40 |
+00:31:46.2 |
HIP 113610 |
21.13 |
| 2026-09-23 12:00 |
23:00:16.94 |
+00:31:29.1 |
HIP 113610 |
21.00 |
| 2026-09-24 00:00 |
23:00:14.49 |
+00:31:12.1 |
HIP 113610 |
20.89 |
| 2026-09-24 12:00 |
23:00:12.05 |
+00:30:55.0 |
HIP 113610 |
20.79 |
| 2026-09-25 00:00 |
23:00:09.61 |
+00:30:37.9 |
HIP 113610 |
20.72 |
| 2026-09-25 12:00 |
23:00:07.18 |
+00:30:20.8 |
HIP 113610 |
20.67 |
| 2026-09-26 00:00 |
23:00:04.75 |
+00:30:03.7 |
HIP 113610 |
20.65 |
| 2026-09-26 12:00 |
23:00:02.34 |
+00:29:46.7 |
HIP 113610 |
20.64 |
| 2026-09-27 00:00 |
22:59:59.93 |
+00:29:29.6 |
HIP 113610 |
20.65 |
| 2026-09-27 12:00 |
22:59:57.53 |
+00:29:12.6 |
HIP 113610 |
20.69 |
| 2026-09-28 00:00 |
22:59:55.13 |
+00:28:55.5 |
HIP 113610 |
20.74 |
| 2026-09-28 12:00 |
22:59:52.75 |
+00:28:38.5 |
HIP 113610 |
20.81 |
| 2026-09-29 00:00 |
22:59:50.37 |
+00:28:21.5 |
HIP 113610 |
20.91 |
| 2026-09-29 12:00 |
22:59:48.00 |
+00:28:04.5 |
HIP 113610 |
21.02 |
| 2026-09-30 00:00 |
22:59:45.64 |
+00:27:47.5 |
HIP 113610 |
21.15 |
| 2026-09-30 12:00 |
22:59:43.29 |
+00:27:30.5 |
HIP 113610 |
21.30 |
| 2026-10-01 00:00 |
22:59:40.95 |
+00:27:13.6 |
HIP 113610 |
21.47 |
| 2026-10-01 12:00 |
22:59:38.61 |
+00:26:56.6 |
HIP 113610 |
21.66 |
| 2026-10-02 00:00 |
22:59:36.29 |
+00:26:39.7 |
HIP 113610 |
21.86 |
| 2026-10-02 12:00 |
22:59:33.97 |
+00:26:22.8 |
HIP 113610 |
22.07 |
| 2026-10-03 00:00 |
22:59:31.66 |
+00:26:06.0 |
HIP 113610 |
22.30 |
| 2026-10-03 12:00 |
22:59:29.37 |
+00:25:49.1 |
HIP 113610 |
22.55 |
| 2026-10-04 00:00 |
22:59:27.08 |
+00:25:32.3 |
HIP 113610 |
22.81 |
| 2026-10-04 12:00 |
22:59:24.80 |
+00:25:15.5 |
HIP 113610 |
23.08 |
| 2026-10-05 00:00 |
22:59:22.54 |
+00:24:58.7 |
HIP 113610 |
23.37 |
| 2026-10-05 12:00 |
22:59:20.28 |
+00:24:41.9 |
HIP 113610 |
23.66 |
| 2026-10-06 00:00 |
22:59:18.03 |
+00:24:25.2 |
HIP 113610 |
23.97 |
| 2026-10-06 12:00 |
22:59:15.80 |
+00:24:08.5 |
HIP 113610 |
24.29 |
| 2026-10-07 00:00 |
22:59:13.57 |
+00:23:51.9 |
HIP 113610 |
24.61 |
| 2026-10-07 12:00 |
22:59:11.36 |
+00:23:35.3 |
HIP 113610 |
24.95 |
| 2026-10-08 00:00 |
22:59:09.16 |
+00:23:18.7 |
HIP 113610 |
25.29 |
| 2026-10-08 12:00 |
22:59:06.97 |
+00:23:02.1 |
HIP 113610 |
25.65 |
| 2026-10-09 00:00 |
22:59:04.79 |
+00:22:45.6 |
HIP 113610 |
26.01 |
| 2026-10-09 12:00 |
22:59:02.62 |
+00:22:29.1 |
HIP 113610 |
26.37 |
| 2026-10-10 00:00 |
22:59:00.47 |
+00:22:12.7 |
HIP 113610 |
26.75 |
| 2026-10-10 12:00 |
22:58:58.33 |
+00:21:56.3 |
HIP 113610 |
27.13 |
| 2026-10-11 00:00 |
22:58:56.20 |
+00:21:39.9 |
HIP 113610 |
27.51 |