| Parameter |
Value |
| Designation |
C/1998 U1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-05-02T12:00:10.497600Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:57Z |
| Obs used |
122 |
| NEO |
- |
| M1 |
9.500 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1998-11-12.0000000 |
| e |
1.00043848 |
| q (au) |
3.975445 |
| a (au) |
-9066.409392 |
| i (deg) |
156.428505 |
| Ω (om, deg) |
210.457099 |
| ω (w, deg) |
124.645648 |
| M (ma, deg) |
0.000221 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.174 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.174 |
| n |
2.000 |
| gf |
0.858 |
| gb |
-0.501 |
| k |
1.000 |
| δ90 |
2.819 |
| 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) |
| 2026-06-01 00:00 |
20:32:27.61 |
-43:21:15.7 |
HIP 101415 |
7.57 |
| 2026-06-01 12:00 |
20:32:25.56 |
-43:21:33.6 |
HIP 101415 |
8.01 |
| 2026-06-02 00:00 |
20:32:23.48 |
-43:21:51.5 |
HIP 101415 |
8.45 |
| 2026-06-02 12:00 |
20:32:21.38 |
-43:22:09.3 |
HIP 101415 |
8.90 |
| 2026-06-03 00:00 |
20:32:19.26 |
-43:22:27.2 |
HIP 101415 |
9.36 |
| 2026-06-03 12:00 |
20:32:17.12 |
-43:22:45.0 |
HIP 101415 |
9.82 |
| 2026-06-04 00:00 |
20:32:14.95 |
-43:23:02.8 |
HIP 101415 |
10.29 |
| 2026-06-04 12:00 |
20:32:12.76 |
-43:23:20.6 |
HIP 101415 |
10.77 |
| 2026-06-05 00:00 |
20:32:10.55 |
-43:23:38.3 |
HIP 101415 |
11.25 |
| 2026-06-05 12:00 |
20:32:08.31 |
-43:23:56.1 |
HIP 101415 |
11.74 |
| 2026-06-06 00:00 |
20:32:06.06 |
-43:24:13.8 |
HIP 101415 |
12.23 |
| 2026-06-06 12:00 |
20:32:03.78 |
-43:24:31.5 |
HIP 101415 |
12.72 |
| 2026-06-07 00:00 |
20:32:01.47 |
-43:24:49.1 |
HIP 101415 |
13.22 |
| 2026-06-07 12:00 |
20:31:59.15 |
-43:25:06.7 |
HIP 101415 |
13.73 |
| 2026-06-08 00:00 |
20:31:56.80 |
-43:25:24.3 |
HIP 101415 |
14.24 |
| 2026-06-08 12:00 |
20:31:54.43 |
-43:25:41.9 |
HIP 101415 |
14.75 |
| 2026-06-09 00:00 |
20:31:52.04 |
-43:25:59.4 |
HIP 101415 |
15.27 |
| 2026-06-09 12:00 |
20:31:49.63 |
-43:26:16.9 |
HIP 101415 |
15.79 |
| 2026-06-10 00:00 |
20:31:47.20 |
-43:26:34.3 |
HIP 101415 |
16.31 |
| 2026-06-10 12:00 |
20:31:44.75 |
-43:26:51.7 |
HIP 101415 |
16.84 |
| 2026-06-11 00:00 |
20:31:42.27 |
-43:27:09.1 |
HIP 101415 |
17.37 |
| 2026-06-11 12:00 |
20:31:39.77 |
-43:27:26.4 |
HIP 101415 |
17.90 |
| 2026-06-12 00:00 |
20:31:37.26 |
-43:27:43.7 |
HIP 101415 |
18.44 |
| 2026-06-12 12:00 |
20:31:34.72 |
-43:28:00.9 |
HIP 101415 |
18.98 |
| 2026-06-13 00:00 |
20:31:32.16 |
-43:28:18.1 |
HIP 101415 |
19.52 |
| 2026-06-13 12:00 |
20:31:29.58 |
-43:28:35.3 |
HIP 101415 |
20.07 |
| 2026-06-14 00:00 |
20:31:26.99 |
-43:28:52.4 |
HIP 101415 |
20.62 |
| 2026-06-14 12:00 |
20:31:24.37 |
-43:29:09.4 |
HIP 101415 |
21.17 |
| 2026-06-15 00:00 |
20:31:21.73 |
-43:29:26.4 |
HIP 101415 |
21.72 |
| 2026-06-15 12:00 |
20:31:19.07 |
-43:29:43.4 |
HIP 101415 |
22.28 |
| 2026-06-16 00:00 |
20:31:16.40 |
-43:30:00.3 |
HIP 101415 |
22.84 |
| 2026-06-16 12:00 |
20:31:13.70 |
-43:30:17.1 |
HIP 101415 |
23.40 |
| 2026-06-17 00:00 |
20:31:10.99 |
-43:30:33.9 |
HIP 101415 |
23.97 |
| 2026-06-17 12:00 |
20:31:08.25 |
-43:30:50.6 |
HIP 101415 |
24.54 |
| 2026-06-18 00:00 |
20:31:05.50 |
-43:31:07.3 |
HIP 101415 |
25.11 |
| 2026-06-18 12:00 |
20:31:02.73 |
-43:31:23.9 |
HIP 101415 |
25.68 |
| 2026-06-19 00:00 |
20:30:59.94 |
-43:31:40.4 |
HIP 101415 |
26.26 |
| 2026-06-19 12:00 |
20:30:57.14 |
-43:31:56.9 |
HIP 101415 |
26.84 |
| 2026-06-20 00:00 |
20:30:54.31 |
-43:32:13.3 |
HIP 101415 |
27.42 |
| 2026-06-20 12:00 |
20:30:51.47 |
-43:32:29.6 |
HIP 101415 |
28.00 |
| 2026-06-21 00:00 |
20:30:48.61 |
-43:32:45.9 |
HIP 101415 |
28.58 |
| 2026-06-21 12:00 |
20:30:45.74 |
-43:33:02.1 |
HIP 101415 |
29.17 |
| 2026-06-22 00:00 |
20:30:42.85 |
-43:33:18.3 |
HIP 101415 |
29.76 |