| Parameter |
Value |
| Designation |
C/1998 G1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-11-16T14:59:02.595840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:53Z |
| Obs used |
161 |
| NEO |
- |
| M1 |
13.800 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1998-04-21.0000000 |
| e |
0.82369261 |
| q (au) |
2.133379 |
| a (au) |
12.100336 |
| i (deg) |
109.714727 |
| Ω (om, deg) |
341.383665 |
| ω (w, deg) |
236.322318 |
| M (ma, deg) |
355.091490 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.797 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.797 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1998-04-02 |
1998-11-16 |
+14.8291 |
-7.029 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
19:37:21.06 |
+39:59:22.2 |
HIP 96501 |
13.66 |
| 2026-05-12 12:00 |
19:37:17.03 |
+40:00:30.7 |
HIP 96501 |
12.42 |
| 2026-05-13 00:00 |
19:37:12.94 |
+40:01:38.9 |
HIP 96501 |
11.21 |
| 2026-05-13 12:00 |
19:37:08.79 |
+40:02:46.7 |
HIP 96501 |
10.06 |
| 2026-05-14 00:00 |
19:37:04.59 |
+40:03:54.1 |
HIP 96501 |
8.97 |
| 2026-05-14 12:00 |
19:37:00.32 |
+40:05:01.3 |
HIP 96501 |
7.98 |
| 2026-05-15 00:00 |
19:36:55.99 |
+40:06:08.0 |
HIP 96501 |
7.14 |
| 2026-05-15 12:00 |
19:36:51.61 |
+40:07:14.4 |
HIP 96501 |
6.49 |
| 2026-05-16 00:00 |
19:36:47.16 |
+40:08:20.4 |
HIP 96501 |
6.11 |
| 2026-05-16 12:00 |
19:36:42.66 |
+40:09:26.0 |
HIP 96501 |
6.05 |
| 2026-05-17 00:00 |
19:36:38.11 |
+40:10:31.3 |
HIP 96501 |
6.31 |
| 2026-05-17 12:00 |
19:36:33.49 |
+40:11:36.2 |
HIP 96501 |
6.86 |
| 2026-05-18 00:00 |
19:36:28.82 |
+40:12:40.7 |
HIP 96501 |
7.65 |
| 2026-05-18 12:00 |
19:36:24.09 |
+40:13:44.8 |
HIP 96501 |
8.59 |
| 2026-05-19 00:00 |
19:36:19.30 |
+40:14:48.4 |
HIP 96501 |
9.66 |
| 2026-05-19 12:00 |
19:36:14.46 |
+40:15:51.7 |
HIP 96501 |
10.81 |
| 2026-05-20 00:00 |
19:36:09.56 |
+40:16:54.6 |
HIP 96501 |
12.03 |
| 2026-05-20 12:00 |
19:36:04.60 |
+40:17:57.0 |
HIP 96501 |
13.28 |
| 2026-05-21 00:00 |
19:35:59.59 |
+40:18:59.0 |
HIP 96501 |
14.57 |
| 2026-05-21 12:00 |
19:35:54.53 |
+40:20:00.6 |
HIP 96501 |
15.89 |
| 2026-05-22 00:00 |
19:35:49.41 |
+40:21:01.8 |
HIP 96501 |
17.23 |
| 2026-05-22 12:00 |
19:35:44.23 |
+40:22:02.5 |
HIP 96501 |
18.58 |
| 2026-05-23 00:00 |
19:35:39.01 |
+40:23:02.8 |
HIP 96501 |
19.95 |
| 2026-05-23 12:00 |
19:35:33.72 |
+40:24:02.7 |
HIP 96501 |
21.32 |
| 2026-05-24 00:00 |
19:35:28.39 |
+40:25:02.1 |
HIP 96501 |
22.71 |
| 2026-05-24 12:00 |
19:35:23.00 |
+40:26:01.0 |
HIP 96501 |
24.10 |
| 2026-05-25 00:00 |
19:35:17.56 |
+40:26:59.5 |
HIP 96501 |
25.50 |
| 2026-05-25 12:00 |
19:35:12.07 |
+40:27:57.5 |
HIP 96371 |
26.72 |
| 2026-05-26 00:00 |
19:35:06.53 |
+40:28:55.1 |
HIP 96528 |
27.58 |
| 2026-05-26 12:00 |
19:35:00.93 |
+40:29:52.2 |
HIP 96528 |
28.42 |
| 2026-05-27 00:00 |
19:34:55.28 |
+40:30:48.8 |
HIP 96528 |
29.31 |
| 2026-05-27 12:00 |
19:34:49.58 |
+40:31:45.0 |
HIP 96528 |
30.25 |
| 2026-05-28 00:00 |
19:34:43.84 |
+40:32:40.6 |
HIP 96528 |
31.23 |
| 2026-05-28 12:00 |
19:34:38.04 |
+40:33:35.8 |
HIP 96528 |
32.27 |
| 2026-05-29 00:00 |
19:34:32.19 |
+40:34:30.5 |
HIP 96528 |
33.34 |
| 2026-05-29 12:00 |
19:34:26.29 |
+40:35:24.7 |
HIP 96528 |
34.44 |
| 2026-05-30 00:00 |
19:34:20.35 |
+40:36:18.4 |
HIP 96448 |
34.82 |
| 2026-05-30 12:00 |
19:34:14.35 |
+40:37:11.5 |
HIP 96448 |
35.05 |
| 2026-05-31 00:00 |
19:34:08.31 |
+40:38:04.2 |
HIP 96448 |
35.34 |
| 2026-05-31 12:00 |
19:34:02.22 |
+40:38:56.4 |
HIP 96104 |
34.69 |
| 2026-06-01 00:00 |
19:33:56.08 |
+40:39:48.1 |
HIP 96104 |
33.34 |
| 2026-06-01 12:00 |
19:33:49.89 |
+40:40:39.2 |
HIP 96104 |
32.01 |
| 2026-06-02 00:00 |
19:33:43.66 |
+40:41:29.8 |
HIP 96104 |
30.68 |