| Parameter |
Value |
| Designation |
C/1999 K8 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2000-04-24T06:58:48.679680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:00Z |
| Obs used |
610 |
| NEO |
- |
| M1 |
9.400 |
| K1 |
5.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2000-03-20.0000000 |
| e |
1.00071246 |
| q (au) |
4.200554 |
| a (au) |
-5895.868027 |
| i (deg) |
52.733975 |
| Ω (om, deg) |
195.394218 |
| ω (w, deg) |
164.619681 |
| M (ma, deg) |
-0.000077 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.474 + 3.588\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.474 |
| n |
3.588 |
| gf |
1.000 |
| gb |
-0.500 |
| 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 |
| 1998-08-19 |
2000-02-01 |
+9.8022 |
-7.106 |
| 2000-05-28 |
2001-08-18 |
+4.3226 |
-3.002 |
| 2001-08-18 |
2003-03-07 |
-5.0352 |
+4.588 |
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 |
09:45:30.29 |
-26:17:23.8 |
HIP 47923 |
7.01 |
| 2026-09-20 12:00 |
09:45:32.66 |
-26:17:44.7 |
HIP 47923 |
6.60 |
| 2026-09-21 00:00 |
09:45:35.02 |
-26:18:05.7 |
HIP 47923 |
6.23 |
| 2026-09-21 12:00 |
09:45:37.36 |
-26:18:26.8 |
HIP 47923 |
5.92 |
| 2026-09-22 00:00 |
09:45:39.70 |
-26:18:48.1 |
HIP 47923 |
5.66 |
| 2026-09-22 12:00 |
09:45:42.02 |
-26:19:09.4 |
HIP 47923 |
5.46 |
| 2026-09-23 00:00 |
09:45:44.33 |
-26:19:30.9 |
HIP 47923 |
5.34 |
| 2026-09-23 12:00 |
09:45:46.62 |
-26:19:52.6 |
HIP 47923 |
5.29 |
| 2026-09-24 00:00 |
09:45:48.91 |
-26:20:14.3 |
HIP 47923 |
5.32 |
| 2026-09-24 12:00 |
09:45:51.17 |
-26:20:36.1 |
HIP 47923 |
5.42 |
| 2026-09-25 00:00 |
09:45:53.43 |
-26:20:58.1 |
HIP 47923 |
5.60 |
| 2026-09-25 12:00 |
09:45:55.67 |
-26:21:20.2 |
HIP 47923 |
5.84 |
| 2026-09-26 00:00 |
09:45:57.90 |
-26:21:42.3 |
HIP 47923 |
6.14 |
| 2026-09-26 12:00 |
09:46:00.12 |
-26:22:04.6 |
HIP 47923 |
6.48 |
| 2026-09-27 00:00 |
09:46:02.32 |
-26:22:27.0 |
HIP 47923 |
6.87 |
| 2026-09-27 12:00 |
09:46:04.50 |
-26:22:49.5 |
HIP 47923 |
7.29 |
| 2026-09-28 00:00 |
09:46:06.68 |
-26:23:12.2 |
HIP 47923 |
7.73 |
| 2026-09-28 12:00 |
09:46:08.83 |
-26:23:34.9 |
HIP 47923 |
8.20 |
| 2026-09-29 00:00 |
09:46:10.98 |
-26:23:57.7 |
HIP 47923 |
8.69 |
| 2026-09-29 12:00 |
09:46:13.11 |
-26:24:20.6 |
HIP 47923 |
9.19 |
| 2026-09-30 00:00 |
09:46:15.22 |
-26:24:43.6 |
HIP 47923 |
9.71 |
| 2026-09-30 12:00 |
09:46:17.32 |
-26:25:06.8 |
HIP 47923 |
10.24 |
| 2026-10-01 00:00 |
09:46:19.41 |
-26:25:30.0 |
HIP 47923 |
10.77 |
| 2026-10-01 12:00 |
09:46:21.48 |
-26:25:53.3 |
HIP 47923 |
11.32 |
| 2026-10-02 00:00 |
09:46:23.53 |
-26:26:16.7 |
HIP 47923 |
11.86 |
| 2026-10-02 12:00 |
09:46:25.57 |
-26:26:40.2 |
HIP 47923 |
12.42 |
| 2026-10-03 00:00 |
09:46:27.59 |
-26:27:03.8 |
HIP 47923 |
12.98 |
| 2026-10-03 12:00 |
09:46:29.60 |
-26:27:27.5 |
HIP 47923 |
13.54 |
| 2026-10-04 00:00 |
09:46:31.59 |
-26:27:51.3 |
HIP 47923 |
14.10 |
| 2026-10-04 12:00 |
09:46:33.57 |
-26:28:15.1 |
HIP 47923 |
14.67 |
| 2026-10-05 00:00 |
09:46:35.53 |
-26:28:39.1 |
HIP 47923 |
15.23 |
| 2026-10-05 12:00 |
09:46:37.47 |
-26:29:03.1 |
HIP 47923 |
15.80 |
| 2026-10-06 00:00 |
09:46:39.40 |
-26:29:27.2 |
HIP 47923 |
16.37 |
| 2026-10-06 12:00 |
09:46:41.31 |
-26:29:51.4 |
HIP 47923 |
16.94 |
| 2026-10-07 00:00 |
09:46:43.20 |
-26:30:15.7 |
HIP 47923 |
17.51 |
| 2026-10-07 12:00 |
09:46:45.08 |
-26:30:40.0 |
HIP 47923 |
18.08 |
| 2026-10-08 00:00 |
09:46:46.93 |
-26:31:04.4 |
HIP 47923 |
18.65 |
| 2026-10-08 12:00 |
09:46:48.78 |
-26:31:28.9 |
HIP 47923 |
19.22 |
| 2026-10-09 00:00 |
09:46:50.60 |
-26:31:53.5 |
HIP 47923 |
19.79 |
| 2026-10-09 12:00 |
09:46:52.41 |
-26:32:18.1 |
HIP 47923 |
20.35 |
| 2026-10-10 00:00 |
09:46:54.20 |
-26:32:42.8 |
HIP 47923 |
20.92 |
| 2026-10-10 12:00 |
09:46:55.97 |
-26:33:07.6 |
HIP 47923 |
21.49 |
| 2026-10-11 00:00 |
09:46:57.72 |
-26:33:32.4 |
HIP 47923 |
22.05 |