| Parameter |
Value |
| Designation |
C/1998 K2 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-09-01T05:31:38.231040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:53Z |
| Obs used |
201 |
| NEO |
- |
| M1 |
10.300 |
| K1 |
5.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1998-10-01.0000000 |
| e |
0.99927629 |
| q (au) |
2.323478 |
| a (au) |
3210.507001 |
| i (deg) |
64.456675 |
| Ω (om, deg) |
68.781077 |
| ω (w, deg) |
221.417912 |
| M (ma, deg) |
0.000161 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.927 + 2.178\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.927 |
| n |
2.178 |
| gf |
1.000 |
| gb |
-0.601 |
| k |
0.800 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
04:56:11.71 |
+37:35:48.2 |
HIP 23013 |
18.66 |
| 2026-07-29 12:00 |
04:56:13.60 |
+37:35:59.0 |
HIP 23013 |
18.32 |
| 2026-07-30 00:00 |
04:56:15.46 |
+37:36:09.9 |
HIP 23013 |
17.98 |
| 2026-07-30 12:00 |
04:56:17.31 |
+37:36:20.8 |
HIP 23013 |
17.65 |
| 2026-07-31 00:00 |
04:56:19.15 |
+37:36:31.7 |
HIP 23013 |
17.32 |
| 2026-07-31 12:00 |
04:56:20.96 |
+37:36:42.7 |
HIP 23013 |
17.00 |
| 2026-08-01 00:00 |
04:56:22.75 |
+37:36:53.6 |
HIP 23013 |
16.68 |
| 2026-08-01 12:00 |
04:56:24.53 |
+37:37:04.6 |
HIP 23013 |
16.36 |
| 2026-08-02 00:00 |
04:56:26.28 |
+37:37:15.6 |
HIP 23013 |
16.06 |
| 2026-08-02 12:00 |
04:56:28.01 |
+37:37:26.6 |
HIP 23013 |
15.75 |
| 2026-08-03 00:00 |
04:56:29.73 |
+37:37:37.7 |
HIP 23013 |
15.45 |
| 2026-08-03 12:00 |
04:56:31.43 |
+37:37:48.7 |
HIP 23013 |
15.16 |
| 2026-08-04 00:00 |
04:56:33.10 |
+37:37:59.8 |
HIP 23013 |
14.87 |
| 2026-08-04 12:00 |
04:56:34.76 |
+37:38:10.9 |
HIP 23013 |
14.58 |
| 2026-08-05 00:00 |
04:56:36.39 |
+37:38:22.0 |
HIP 23013 |
14.30 |
| 2026-08-05 12:00 |
04:56:38.01 |
+37:38:33.2 |
HIP 23013 |
14.03 |
| 2026-08-06 00:00 |
04:56:39.60 |
+37:38:44.3 |
HIP 23013 |
13.76 |
| 2026-08-06 12:00 |
04:56:41.18 |
+37:38:55.5 |
HIP 23013 |
13.50 |
| 2026-08-07 00:00 |
04:56:42.73 |
+37:39:06.7 |
HIP 23013 |
13.24 |
| 2026-08-07 12:00 |
04:56:44.26 |
+37:39:17.9 |
HIP 23013 |
12.99 |
| 2026-08-08 00:00 |
04:56:45.77 |
+37:39:29.1 |
HIP 23013 |
12.74 |
| 2026-08-08 12:00 |
04:56:47.26 |
+37:39:40.3 |
HIP 23013 |
12.50 |
| 2026-08-09 00:00 |
04:56:48.73 |
+37:39:51.5 |
HIP 23013 |
12.27 |
| 2026-08-09 12:00 |
04:56:50.18 |
+37:40:02.8 |
HIP 23013 |
12.04 |
| 2026-08-10 00:00 |
04:56:51.61 |
+37:40:14.0 |
HIP 23013 |
11.81 |
| 2026-08-10 12:00 |
04:56:53.01 |
+37:40:25.3 |
HIP 23013 |
11.60 |
| 2026-08-11 00:00 |
04:56:54.39 |
+37:40:36.6 |
HIP 23013 |
11.38 |
| 2026-08-11 12:00 |
04:56:55.76 |
+37:40:47.9 |
HIP 23013 |
11.18 |
| 2026-08-12 00:00 |
04:56:57.09 |
+37:40:59.2 |
HIP 23013 |
10.98 |
| 2026-08-12 12:00 |
04:56:58.41 |
+37:41:10.5 |
HIP 23013 |
10.78 |
| 2026-08-13 00:00 |
04:56:59.71 |
+37:41:21.8 |
HIP 23013 |
10.60 |
| 2026-08-13 12:00 |
04:57:00.98 |
+37:41:33.2 |
HIP 23013 |
10.41 |
| 2026-08-14 00:00 |
04:57:02.23 |
+37:41:44.5 |
HIP 23013 |
10.24 |
| 2026-08-14 12:00 |
04:57:03.46 |
+37:41:55.8 |
HIP 23013 |
10.07 |
| 2026-08-15 00:00 |
04:57:04.66 |
+37:42:07.2 |
HIP 23013 |
9.90 |
| 2026-08-15 12:00 |
04:57:05.84 |
+37:42:18.5 |
HIP 23013 |
9.74 |
| 2026-08-16 00:00 |
04:57:07.00 |
+37:42:29.9 |
HIP 23013 |
9.59 |
| 2026-08-16 12:00 |
04:57:08.14 |
+37:42:41.2 |
HIP 23013 |
9.45 |
| 2026-08-17 00:00 |
04:57:09.25 |
+37:42:52.6 |
HIP 23013 |
9.31 |
| 2026-08-17 12:00 |
04:57:10.34 |
+37:43:03.9 |
HIP 23013 |
9.17 |
| 2026-08-18 00:00 |
04:57:11.41 |
+37:43:15.3 |
HIP 23013 |
9.04 |
| 2026-08-18 12:00 |
04:57:12.45 |
+37:43:26.7 |
HIP 23013 |
8.92 |
| 2026-08-19 00:00 |
04:57:13.47 |
+37:43:38.0 |
HIP 23013 |
8.80 |