| Parameter |
Value |
| Designation |
C/1999 G1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-08-01T15:27:45.645120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:57Z |
| Obs used |
76 |
| NEO |
- |
| M1 |
8.000 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1999-04-12.0000000 |
| e |
0.85677293 |
| q (au) |
4.048556 |
| a (au) |
28.266698 |
| i (deg) |
76.568197 |
| Ω (om, deg) |
23.462057 |
| ω (w, deg) |
136.125424 |
| M (ma, deg) |
1.661583 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.052 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.052 |
| n |
2.000 |
| 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) |
| 2026-09-20 00:00 |
02:25:14.98 |
-55:45:33.7 |
HIP 11160 |
16.42 |
| 2026-09-20 12:00 |
02:25:10.83 |
-55:46:03.4 |
HIP 11160 |
16.19 |
| 2026-09-21 00:00 |
02:25:06.63 |
-55:46:32.8 |
HIP 11160 |
15.99 |
| 2026-09-21 12:00 |
02:25:02.41 |
-55:47:01.9 |
HIP 11160 |
15.82 |
| 2026-09-22 00:00 |
02:24:58.16 |
-55:47:30.8 |
HIP 11160 |
15.68 |
| 2026-09-22 12:00 |
02:24:53.88 |
-55:47:59.4 |
HIP 11160 |
15.57 |
| 2026-09-23 00:00 |
02:24:49.56 |
-55:48:27.8 |
HIP 11160 |
15.49 |
| 2026-09-23 12:00 |
02:24:45.22 |
-55:48:55.8 |
HIP 11160 |
15.44 |
| 2026-09-24 00:00 |
02:24:40.85 |
-55:49:23.6 |
HIP 11160 |
15.42 |
| 2026-09-24 12:00 |
02:24:36.44 |
-55:49:51.1 |
HIP 11100 |
15.18 |
| 2026-09-25 00:00 |
02:24:32.01 |
-55:50:18.3 |
HIP 11100 |
14.75 |
| 2026-09-25 12:00 |
02:24:27.55 |
-55:50:45.2 |
HIP 11100 |
14.34 |
| 2026-09-26 00:00 |
02:24:23.06 |
-55:51:11.8 |
HIP 11100 |
13.96 |
| 2026-09-26 12:00 |
02:24:18.54 |
-55:51:38.1 |
HIP 11100 |
13.61 |
| 2026-09-27 00:00 |
02:24:14.00 |
-55:52:04.1 |
HIP 11100 |
13.28 |
| 2026-09-27 12:00 |
02:24:09.43 |
-55:52:29.8 |
HIP 11100 |
12.99 |
| 2026-09-28 00:00 |
02:24:04.83 |
-55:52:55.2 |
HIP 11100 |
12.73 |
| 2026-09-28 12:00 |
02:24:00.20 |
-55:53:20.3 |
HIP 11100 |
12.51 |
| 2026-09-29 00:00 |
02:23:55.55 |
-55:53:45.1 |
HIP 11100 |
12.32 |
| 2026-09-29 12:00 |
02:23:50.87 |
-55:54:09.6 |
HIP 11100 |
12.18 |
| 2026-09-30 00:00 |
02:23:46.16 |
-55:54:33.8 |
HIP 11100 |
12.08 |
| 2026-09-30 12:00 |
02:23:41.43 |
-55:54:57.6 |
HIP 11100 |
12.02 |
| 2026-10-01 00:00 |
02:23:36.68 |
-55:55:21.2 |
HIP 11100 |
12.00 |
| 2026-10-01 12:00 |
02:23:31.89 |
-55:55:44.4 |
HIP 11100 |
12.03 |
| 2026-10-02 00:00 |
02:23:27.09 |
-55:56:07.3 |
HIP 11100 |
12.10 |
| 2026-10-02 12:00 |
02:23:22.26 |
-55:56:29.9 |
HIP 11100 |
12.21 |
| 2026-10-03 00:00 |
02:23:17.41 |
-55:56:52.1 |
HIP 11100 |
12.37 |
| 2026-10-03 12:00 |
02:23:12.53 |
-55:57:14.0 |
HIP 11100 |
12.57 |
| 2026-10-04 00:00 |
02:23:07.63 |
-55:57:35.6 |
HIP 11100 |
12.80 |
| 2026-10-04 12:00 |
02:23:02.71 |
-55:57:56.9 |
HIP 11100 |
13.07 |
| 2026-10-05 00:00 |
02:22:57.76 |
-55:58:17.8 |
HIP 11100 |
13.37 |
| 2026-10-05 12:00 |
02:22:52.80 |
-55:58:38.4 |
HIP 11100 |
13.71 |
| 2026-10-06 00:00 |
02:22:47.81 |
-55:58:58.6 |
HIP 11100 |
14.07 |
| 2026-10-06 12:00 |
02:22:42.80 |
-55:59:18.5 |
HIP 11100 |
14.47 |
| 2026-10-07 00:00 |
02:22:37.77 |
-55:59:38.1 |
HIP 11100 |
14.88 |
| 2026-10-07 12:00 |
02:22:32.72 |
-55:59:57.3 |
HIP 11100 |
15.32 |
| 2026-10-08 00:00 |
02:22:27.65 |
-56:00:16.2 |
HIP 11100 |
15.78 |
| 2026-10-08 12:00 |
02:22:22.56 |
-56:00:34.7 |
HIP 11100 |
16.26 |
| 2026-10-09 00:00 |
02:22:17.45 |
-56:00:52.8 |
HIP 11100 |
16.76 |
| 2026-10-09 12:00 |
02:22:12.32 |
-56:01:10.6 |
HIP 10897 |
16.95 |
| 2026-10-10 00:00 |
02:22:07.17 |
-56:01:28.0 |
HIP 10897 |
16.18 |
| 2026-10-10 12:00 |
02:22:02.01 |
-56:01:45.1 |
HIP 10897 |
15.40 |
| 2026-10-11 00:00 |
02:21:56.83 |
-56:02:01.8 |
HIP 10897 |
14.63 |