| Parameter |
Value |
| Designation |
C/1998 K5 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-07-17T10:42:32.613120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:53Z |
| Obs used |
627 |
| NEO |
- |
| M1 |
15.300 |
| K1 |
28.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1998-07-27.0000000 |
| e |
0.98669128 |
| q (au) |
0.963547 |
| a (au) |
72.399650 |
| i (deg) |
9.927137 |
| Ω (om, deg) |
211.117668 |
| ω (w, deg) |
99.460270 |
| M (ma, deg) |
0.015285 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.295 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.295 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-0.851 |
| k |
0.939 |
| 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 |
| 1998-05-26 |
1998-06-15 |
+45.9853 |
-1.403 |
| 1998-06-15 |
1998-07-16 |
+6.3263 |
+0.583 |
| 1998-07-17 |
1998-09-22 |
-11.0269 |
-0.952 |
| 1998-09-22 |
1998-10-31 |
+26.5628 |
-7.342 |
| 1998-10-31 |
1998-12-19 |
-18.5111 |
+5.933 |
| 1998-12-19 |
1999-02-14 |
-0.4311 |
-1.229 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
07:43:35.55 |
+11:10:01.3 |
HIP 37492 |
31.93 |
| 2026-03-26 12:00 |
07:43:34.76 |
+11:10:09.7 |
HIP 37492 |
31.84 |
| 2026-03-27 00:00 |
07:43:33.99 |
+11:10:18.1 |
HIP 37492 |
31.76 |
| 2026-03-27 12:00 |
07:43:33.25 |
+11:10:26.4 |
HIP 37492 |
31.68 |
| 2026-03-28 00:00 |
07:43:32.53 |
+11:10:34.7 |
HIP 37492 |
31.61 |
| 2026-03-28 12:00 |
07:43:31.82 |
+11:10:43.0 |
HIP 37492 |
31.54 |
| 2026-03-29 00:00 |
07:43:31.15 |
+11:10:51.2 |
HIP 37492 |
31.48 |
| 2026-03-29 12:00 |
07:43:30.49 |
+11:10:59.3 |
HIP 37492 |
31.42 |
| 2026-03-30 00:00 |
07:43:29.85 |
+11:11:07.5 |
HIP 37492 |
31.37 |
| 2026-03-30 12:00 |
07:43:29.24 |
+11:11:15.5 |
HIP 37492 |
31.33 |
| 2026-03-31 00:00 |
07:43:28.64 |
+11:11:23.6 |
HIP 37492 |
31.29 |
| 2026-03-31 12:00 |
07:43:28.07 |
+11:11:31.6 |
HIP 37492 |
31.25 |
| 2026-04-01 00:00 |
07:43:27.52 |
+11:11:39.5 |
HIP 37492 |
31.22 |
| 2026-04-01 12:00 |
07:43:26.99 |
+11:11:47.4 |
HIP 37492 |
31.20 |
| 2026-04-02 00:00 |
07:43:26.49 |
+11:11:55.3 |
HIP 37492 |
31.18 |
| 2026-04-02 12:00 |
07:43:26.00 |
+11:12:03.1 |
HIP 37492 |
31.16 |
| 2026-04-03 00:00 |
07:43:25.54 |
+11:12:10.9 |
HIP 37492 |
31.15 |
| 2026-04-03 12:00 |
07:43:25.10 |
+11:12:18.6 |
HIP 37492 |
31.14 |
| 2026-04-04 00:00 |
07:43:24.68 |
+11:12:26.2 |
HIP 37492 |
31.14 |
| 2026-04-04 12:00 |
07:43:24.28 |
+11:12:33.9 |
HIP 37492 |
31.14 |
| 2026-04-05 00:00 |
07:43:23.91 |
+11:12:41.4 |
HIP 37492 |
31.15 |
| 2026-04-05 12:00 |
07:43:23.56 |
+11:12:49.0 |
HIP 37492 |
31.16 |
| 2026-04-06 00:00 |
07:43:23.22 |
+11:12:56.4 |
HIP 37492 |
31.18 |
| 2026-04-06 12:00 |
07:43:22.92 |
+11:13:03.9 |
HIP 37492 |
31.20 |
| 2026-04-07 00:00 |
07:43:22.63 |
+11:13:11.2 |
HIP 37492 |
31.22 |
| 2026-04-07 12:00 |
07:43:22.36 |
+11:13:18.5 |
HIP 37492 |
31.25 |
| 2026-04-08 00:00 |
07:43:22.12 |
+11:13:25.8 |
HIP 37492 |
31.29 |
| 2026-04-08 12:00 |
07:43:21.90 |
+11:13:33.0 |
HIP 37492 |
31.32 |
| 2026-04-09 00:00 |
07:43:21.70 |
+11:13:40.2 |
HIP 37492 |
31.36 |
| 2026-04-09 12:00 |
07:43:21.52 |
+11:13:47.3 |
HIP 37492 |
31.41 |
| 2026-04-10 00:00 |
07:43:21.37 |
+11:13:54.4 |
HIP 37492 |
31.46 |
| 2026-04-10 12:00 |
07:43:21.23 |
+11:14:01.4 |
HIP 37492 |
31.51 |
| 2026-04-11 00:00 |
07:43:21.12 |
+11:14:08.3 |
HIP 37492 |
31.57 |
| 2026-04-11 12:00 |
07:43:21.03 |
+11:14:15.2 |
HIP 37492 |
31.63 |
| 2026-04-12 00:00 |
07:43:20.97 |
+11:14:22.0 |
HIP 37492 |
31.69 |
| 2026-04-12 12:00 |
07:43:20.92 |
+11:14:28.8 |
HIP 37492 |
31.76 |
| 2026-04-13 00:00 |
07:43:20.90 |
+11:14:35.5 |
HIP 37492 |
31.83 |
| 2026-04-13 12:00 |
07:43:20.90 |
+11:14:42.2 |
HIP 37492 |
31.90 |
| 2026-04-14 00:00 |
07:43:20.92 |
+11:14:48.8 |
HIP 37492 |
31.98 |
| 2026-04-14 12:00 |
07:43:20.96 |
+11:14:55.4 |
HIP 37492 |
32.06 |
| 2026-04-15 00:00 |
07:43:21.02 |
+11:15:01.9 |
HIP 37492 |
32.15 |
| 2026-04-15 12:00 |
07:43:21.11 |
+11:15:08.3 |
HIP 37492 |
32.24 |
| 2026-04-16 00:00 |
07:43:21.22 |
+11:15:14.7 |
HIP 37492 |
32.33 |