| Parameter |
Value |
| Designation |
C/1998 Q1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-06-29T12:12:45.789120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:57Z |
| Obs used |
147 |
| NEO |
- |
| M1 |
14.000 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1998-09-07.0000000 |
| e |
0.99559540 |
| q (au) |
1.577877 |
| a (au) |
358.233578 |
| i (deg) |
32.305811 |
| Ω (om, deg) |
159.784650 |
| ω (w, deg) |
134.732300 |
| M (ma, deg) |
0.010101 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.841 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.841 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.819 |
| k |
0.987 |
| 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 |
06:32:18.34 |
-05:13:05.8 |
HIP 31195 |
9.15 |
| 2026-07-29 12:00 |
06:32:20.47 |
-05:13:15.1 |
HIP 31195 |
8.71 |
| 2026-07-30 00:00 |
06:32:22.58 |
-05:13:24.5 |
HIP 31195 |
8.29 |
| 2026-07-30 12:00 |
06:32:24.69 |
-05:13:34.0 |
HIP 31195 |
7.89 |
| 2026-07-31 00:00 |
06:32:26.79 |
-05:13:43.7 |
HIP 31195 |
7.50 |
| 2026-07-31 12:00 |
06:32:28.88 |
-05:13:53.5 |
HIP 31195 |
7.13 |
| 2026-08-01 00:00 |
06:32:30.96 |
-05:14:03.3 |
HIP 31195 |
6.79 |
| 2026-08-01 12:00 |
06:32:33.02 |
-05:14:13.3 |
HIP 31195 |
6.47 |
| 2026-08-02 00:00 |
06:32:35.08 |
-05:14:23.4 |
HIP 31195 |
6.18 |
| 2026-08-02 12:00 |
06:32:37.13 |
-05:14:33.6 |
HIP 31195 |
5.93 |
| 2026-08-03 00:00 |
06:32:39.17 |
-05:14:44.0 |
HIP 31195 |
5.71 |
| 2026-08-03 12:00 |
06:32:41.19 |
-05:14:54.4 |
HIP 31195 |
5.53 |
| 2026-08-04 00:00 |
06:32:43.21 |
-05:15:04.9 |
HIP 31195 |
5.40 |
| 2026-08-04 12:00 |
06:32:45.22 |
-05:15:15.6 |
HIP 31195 |
5.32 |
| 2026-08-05 00:00 |
06:32:47.21 |
-05:15:26.4 |
HIP 31195 |
5.29 |
| 2026-08-05 12:00 |
06:32:49.20 |
-05:15:37.2 |
HIP 31195 |
5.30 |
| 2026-08-06 00:00 |
06:32:51.17 |
-05:15:48.2 |
HIP 31195 |
5.37 |
| 2026-08-06 12:00 |
06:32:53.13 |
-05:15:59.3 |
HIP 31195 |
5.48 |
| 2026-08-07 00:00 |
06:32:55.08 |
-05:16:10.5 |
HIP 31195 |
5.64 |
| 2026-08-07 12:00 |
06:32:57.02 |
-05:16:21.8 |
HIP 31195 |
5.83 |
| 2026-08-08 00:00 |
06:32:58.95 |
-05:16:33.2 |
HIP 31195 |
6.06 |
| 2026-08-08 12:00 |
06:33:00.86 |
-05:16:44.8 |
HIP 31195 |
6.32 |
| 2026-08-09 00:00 |
06:33:02.77 |
-05:16:56.4 |
HIP 31195 |
6.60 |
| 2026-08-09 12:00 |
06:33:04.66 |
-05:17:08.1 |
HIP 31195 |
6.91 |
| 2026-08-10 00:00 |
06:33:06.54 |
-05:17:19.9 |
HIP 31195 |
7.24 |
| 2026-08-10 12:00 |
06:33:08.40 |
-05:17:31.9 |
HIP 31195 |
7.58 |
| 2026-08-11 00:00 |
06:33:10.26 |
-05:17:43.9 |
HIP 31195 |
7.94 |
| 2026-08-11 12:00 |
06:33:12.10 |
-05:17:56.0 |
HIP 31195 |
8.31 |
| 2026-08-12 00:00 |
06:33:13.93 |
-05:18:08.2 |
HIP 31195 |
8.69 |
| 2026-08-12 12:00 |
06:33:15.75 |
-05:18:20.6 |
HIP 31195 |
9.08 |
| 2026-08-13 00:00 |
06:33:17.55 |
-05:18:33.0 |
HIP 31195 |
9.47 |
| 2026-08-13 12:00 |
06:33:19.34 |
-05:18:45.5 |
HIP 31195 |
9.87 |
| 2026-08-14 00:00 |
06:33:21.11 |
-05:18:58.2 |
HIP 31195 |
10.27 |
| 2026-08-14 12:00 |
06:33:22.88 |
-05:19:10.9 |
HIP 31195 |
10.68 |
| 2026-08-15 00:00 |
06:33:24.63 |
-05:19:23.7 |
HIP 31195 |
11.09 |
| 2026-08-15 12:00 |
06:33:26.36 |
-05:19:36.6 |
HIP 31195 |
11.50 |
| 2026-08-16 00:00 |
06:33:28.08 |
-05:19:49.6 |
HIP 31195 |
11.92 |
| 2026-08-16 12:00 |
06:33:29.79 |
-05:20:02.7 |
HIP 31339 |
12.12 |
| 2026-08-17 00:00 |
06:33:31.48 |
-05:20:15.8 |
HIP 31339 |
11.71 |
| 2026-08-17 12:00 |
06:33:33.16 |
-05:20:29.1 |
HIP 31339 |
11.30 |
| 2026-08-18 00:00 |
06:33:34.83 |
-05:20:42.5 |
HIP 31339 |
10.91 |
| 2026-08-18 12:00 |
06:33:36.48 |
-05:20:55.9 |
HIP 31339 |
10.52 |
| 2026-08-19 00:00 |
06:33:38.12 |
-05:21:09.4 |
HIP 31339 |
10.15 |