| Parameter |
Value |
| Designation |
C/1998 W3 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-10-06T17:14:54.798720Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:57Z |
| Obs used |
162 |
| NEO |
- |
| M1 |
6.500 |
| K1 |
10.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1999-02-19.0000000 |
| e |
1.00089959 |
| q (au) |
4.914592 |
| a (au) |
-5463.131541 |
| i (deg) |
129.186877 |
| Ω (om, deg) |
123.916981 |
| ω (w, deg) |
6.886773 |
| M (ma, deg) |
0.000330 |
Magnitude
Scatter + Global Linear
$$
M_a = (2.412 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
2.412 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
21:17:32.99 |
+09:13:12.8 |
HIP 105093 |
13.10 |
| 2026-07-29 12:00 |
21:17:30.53 |
+09:13:03.2 |
HIP 105093 |
12.81 |
| 2026-07-30 00:00 |
21:17:28.07 |
+09:12:53.5 |
HIP 105093 |
12.55 |
| 2026-07-30 12:00 |
21:17:25.60 |
+09:12:43.7 |
HIP 105093 |
12.30 |
| 2026-07-31 00:00 |
21:17:23.13 |
+09:12:33.6 |
HIP 105093 |
12.09 |
| 2026-07-31 12:00 |
21:17:20.65 |
+09:12:23.5 |
HIP 105093 |
11.90 |
| 2026-08-01 00:00 |
21:17:18.18 |
+09:12:13.2 |
HIP 105093 |
11.74 |
| 2026-08-01 12:00 |
21:17:15.70 |
+09:12:02.7 |
HIP 105093 |
11.61 |
| 2026-08-02 00:00 |
21:17:13.21 |
+09:11:52.1 |
HIP 105093 |
11.51 |
| 2026-08-02 12:00 |
21:17:10.73 |
+09:11:41.4 |
HIP 105093 |
11.45 |
| 2026-08-03 00:00 |
21:17:08.24 |
+09:11:30.5 |
HIP 105093 |
11.41 |
| 2026-08-03 12:00 |
21:17:05.74 |
+09:11:19.4 |
HIP 105093 |
11.42 |
| 2026-08-04 00:00 |
21:17:03.25 |
+09:11:08.3 |
HIP 105093 |
11.45 |
| 2026-08-04 12:00 |
21:17:00.76 |
+09:10:56.9 |
HIP 105093 |
11.52 |
| 2026-08-05 00:00 |
21:16:58.26 |
+09:10:45.5 |
HIP 105093 |
11.62 |
| 2026-08-05 12:00 |
21:16:55.76 |
+09:10:33.9 |
HIP 105093 |
11.76 |
| 2026-08-06 00:00 |
21:16:53.26 |
+09:10:22.1 |
HIP 105093 |
11.93 |
| 2026-08-06 12:00 |
21:16:50.75 |
+09:10:10.2 |
HIP 105093 |
12.13 |
| 2026-08-07 00:00 |
21:16:48.25 |
+09:09:58.2 |
HIP 105093 |
12.35 |
| 2026-08-07 12:00 |
21:16:45.75 |
+09:09:46.0 |
HIP 105093 |
12.61 |
| 2026-08-08 00:00 |
21:16:43.24 |
+09:09:33.7 |
HIP 105093 |
12.89 |
| 2026-08-08 12:00 |
21:16:40.74 |
+09:09:21.2 |
HIP 105093 |
13.20 |
| 2026-08-09 00:00 |
21:16:38.23 |
+09:09:08.6 |
HIP 105093 |
13.53 |
| 2026-08-09 12:00 |
21:16:35.72 |
+09:08:55.9 |
HIP 105093 |
13.88 |
| 2026-08-10 00:00 |
21:16:33.22 |
+09:08:43.0 |
HIP 105093 |
14.25 |
| 2026-08-10 12:00 |
21:16:30.71 |
+09:08:30.0 |
HIP 105093 |
14.64 |
| 2026-08-11 00:00 |
21:16:28.21 |
+09:08:16.8 |
HIP 105093 |
15.04 |
| 2026-08-11 12:00 |
21:16:25.70 |
+09:08:03.5 |
HIP 105093 |
15.47 |
| 2026-08-12 00:00 |
21:16:23.20 |
+09:07:50.1 |
HIP 105093 |
15.91 |
| 2026-08-12 12:00 |
21:16:20.69 |
+09:07:36.6 |
HIP 105038 |
16.29 |
| 2026-08-13 00:00 |
21:16:18.19 |
+09:07:22.9 |
HIP 105038 |
16.64 |
| 2026-08-13 12:00 |
21:16:15.69 |
+09:07:09.1 |
HIP 105038 |
17.00 |
| 2026-08-14 00:00 |
21:16:13.19 |
+09:06:55.1 |
HIP 105038 |
17.39 |
| 2026-08-14 12:00 |
21:16:10.69 |
+09:06:41.0 |
HIP 105038 |
17.79 |
| 2026-08-15 00:00 |
21:16:08.20 |
+09:06:26.8 |
HIP 105038 |
18.21 |
| 2026-08-15 12:00 |
21:16:05.70 |
+09:06:12.5 |
HIP 105038 |
18.64 |
| 2026-08-16 00:00 |
21:16:03.21 |
+09:05:58.1 |
HIP 104895 |
18.32 |
| 2026-08-16 12:00 |
21:16:00.72 |
+09:05:43.5 |
HIP 104895 |
17.66 |
| 2026-08-17 00:00 |
21:15:58.24 |
+09:05:28.8 |
HIP 104895 |
17.00 |
| 2026-08-17 12:00 |
21:15:55.75 |
+09:05:13.9 |
HIP 104895 |
16.34 |
| 2026-08-18 00:00 |
21:15:53.27 |
+09:04:59.0 |
HIP 104895 |
15.68 |
| 2026-08-18 12:00 |
21:15:50.80 |
+09:04:43.9 |
HIP 104895 |
15.02 |
| 2026-08-19 00:00 |
21:15:48.32 |
+09:04:28.7 |
HIP 104895 |
14.36 |