| Parameter |
Value |
| Designation |
C/1999 S4 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2000-07-26T03:54:28.607040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:02Z |
| Obs used |
1230 |
| NEO |
- |
| M1 |
9.600 |
| K1 |
6.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2000-02-13.0000000 |
| e |
1.00010829 |
| q (au) |
0.765089 |
| a (au) |
-7064.946187 |
| i (deg) |
149.384928 |
| Ω (om, deg) |
83.180585 |
| ω (w, deg) |
151.049994 |
| M (ma, deg) |
-0.000272 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.703 + 2.930\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.703 |
| n |
2.930 |
| gf |
0.800 |
| gb |
-0.588 |
| k |
0.800 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1999-09-27 |
1999-12-05 |
+5.1833 |
-3.118 |
| 1999-12-05 |
2000-06-22 |
+2.2171 |
-1.141 |
| 2000-06-22 |
2000-07-26 |
-14.5392 |
-1.393 |
| 2000-07-26 |
2000-08-30 |
+15.4677 |
+2.517 |
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 |
08:03:27.61 |
-00:12:12.7 |
HIP 39262 |
28.03 |
| 2026-09-20 12:00 |
08:03:28.76 |
-00:12:26.6 |
HIP 39262 |
28.38 |
| 2026-09-21 00:00 |
08:03:29.89 |
-00:12:40.5 |
HIP 39262 |
28.73 |
| 2026-09-21 12:00 |
08:03:31.00 |
-00:12:54.4 |
HIP 39262 |
29.07 |
| 2026-09-22 00:00 |
08:03:32.10 |
-00:13:08.3 |
HIP 39262 |
29.41 |
| 2026-09-22 12:00 |
08:03:33.18 |
-00:13:22.2 |
HIP 39262 |
29.75 |
| 2026-09-23 00:00 |
08:03:34.25 |
-00:13:36.2 |
HIP 39262 |
30.09 |
| 2026-09-23 12:00 |
08:03:35.29 |
-00:13:50.1 |
HIP 39262 |
30.42 |
| 2026-09-24 00:00 |
08:03:36.32 |
-00:14:04.0 |
HIP 39262 |
30.74 |
| 2026-09-24 12:00 |
08:03:37.33 |
-00:14:18.0 |
HIP 39262 |
31.07 |
| 2026-09-25 00:00 |
08:03:38.33 |
-00:14:31.9 |
HIP 39262 |
31.39 |
| 2026-09-25 12:00 |
08:03:39.30 |
-00:14:45.8 |
HIP 39262 |
31.70 |
| 2026-09-26 00:00 |
08:03:40.26 |
-00:14:59.8 |
HIP 39262 |
32.01 |
| 2026-09-26 12:00 |
08:03:41.20 |
-00:15:13.7 |
HIP 39262 |
32.32 |
| 2026-09-27 00:00 |
08:03:42.12 |
-00:15:27.6 |
HIP 39262 |
32.63 |
| 2026-09-27 12:00 |
08:03:43.03 |
-00:15:41.6 |
HIP 39262 |
32.93 |
| 2026-09-28 00:00 |
08:03:43.91 |
-00:15:55.5 |
HIP 39262 |
33.23 |
| 2026-09-28 12:00 |
08:03:44.78 |
-00:16:09.4 |
HIP 39262 |
33.52 |
| 2026-09-29 00:00 |
08:03:45.63 |
-00:16:23.3 |
HIP 39262 |
33.81 |
| 2026-09-29 12:00 |
08:03:46.46 |
-00:16:37.2 |
HIP 39262 |
34.10 |
| 2026-09-30 00:00 |
08:03:47.28 |
-00:16:51.1 |
HIP 39262 |
34.38 |
| 2026-09-30 12:00 |
08:03:48.07 |
-00:17:05.0 |
HIP 39262 |
34.66 |
| 2026-10-01 00:00 |
08:03:48.85 |
-00:17:18.9 |
HIP 39625 |
34.70 |
| 2026-10-01 12:00 |
08:03:49.60 |
-00:17:32.7 |
HIP 39625 |
34.42 |
| 2026-10-02 00:00 |
08:03:50.34 |
-00:17:46.6 |
HIP 39625 |
34.14 |
| 2026-10-02 12:00 |
08:03:51.06 |
-00:18:00.4 |
HIP 39625 |
33.87 |
| 2026-10-03 00:00 |
08:03:51.76 |
-00:18:14.2 |
HIP 39625 |
33.61 |
| 2026-10-03 12:00 |
08:03:52.44 |
-00:18:28.0 |
HIP 39625 |
33.35 |
| 2026-10-04 00:00 |
08:03:53.11 |
-00:18:41.8 |
HIP 39625 |
33.09 |
| 2026-10-04 12:00 |
08:03:53.75 |
-00:18:55.6 |
HIP 39625 |
32.84 |
| 2026-10-05 00:00 |
08:03:54.38 |
-00:19:09.4 |
HIP 39625 |
32.60 |
| 2026-10-05 12:00 |
08:03:54.98 |
-00:19:23.1 |
HIP 39625 |
32.36 |
| 2026-10-06 00:00 |
08:03:55.57 |
-00:19:36.8 |
HIP 39625 |
32.12 |
| 2026-10-06 12:00 |
08:03:56.13 |
-00:19:50.5 |
HIP 39625 |
31.89 |
| 2026-10-07 00:00 |
08:03:56.68 |
-00:20:04.2 |
HIP 39625 |
31.67 |
| 2026-10-07 12:00 |
08:03:57.21 |
-00:20:17.8 |
HIP 39625 |
31.45 |
| 2026-10-08 00:00 |
08:03:57.71 |
-00:20:31.4 |
HIP 39625 |
31.23 |
| 2026-10-08 12:00 |
08:03:58.20 |
-00:20:45.0 |
HIP 39625 |
31.02 |
| 2026-10-09 00:00 |
08:03:58.67 |
-00:20:58.6 |
HIP 39625 |
30.82 |
| 2026-10-09 12:00 |
08:03:59.12 |
-00:21:12.1 |
HIP 39625 |
30.62 |
| 2026-10-10 00:00 |
08:03:59.55 |
-00:21:25.6 |
HIP 39625 |
30.43 |
| 2026-10-10 12:00 |
08:03:59.96 |
-00:21:39.1 |
HIP 39625 |
30.24 |
| 2026-10-11 00:00 |
08:04:00.34 |
-00:21:52.5 |
HIP 39625 |
30.06 |