| 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) |
| 2026-07-29 00:00 |
02:28:53.94 |
-54:38:18.5 |
HIP 11387 |
19.58 |
| 2026-07-29 12:00 |
02:28:54.12 |
-54:38:58.7 |
HIP 11387 |
19.81 |
| 2026-07-30 00:00 |
02:28:54.26 |
-54:39:38.9 |
HIP 11387 |
20.05 |
| 2026-07-30 12:00 |
02:28:54.36 |
-54:40:19.3 |
HIP 11387 |
20.31 |
| 2026-07-31 00:00 |
02:28:54.41 |
-54:40:59.6 |
HIP 11387 |
20.58 |
| 2026-07-31 12:00 |
02:28:54.42 |
-54:41:40.1 |
HIP 11387 |
20.87 |
| 2026-08-01 00:00 |
02:28:54.39 |
-54:42:20.6 |
HIP 11387 |
21.16 |
| 2026-08-01 12:00 |
02:28:54.31 |
-54:43:01.2 |
HIP 11387 |
21.47 |
| 2026-08-02 00:00 |
02:28:54.19 |
-54:43:41.8 |
HIP 11387 |
21.79 |
| 2026-08-02 12:00 |
02:28:54.02 |
-54:44:22.5 |
HIP 11387 |
22.12 |
| 2026-08-03 00:00 |
02:28:53.81 |
-54:45:03.2 |
HIP 11387 |
22.46 |
| 2026-08-03 12:00 |
02:28:53.56 |
-54:45:44.0 |
HIP 11387 |
22.82 |
| 2026-08-04 00:00 |
02:28:53.27 |
-54:46:24.8 |
HIP 11387 |
23.18 |
| 2026-08-04 12:00 |
02:28:52.93 |
-54:47:05.7 |
HIP 11387 |
23.55 |
| 2026-08-05 00:00 |
02:28:52.54 |
-54:47:46.6 |
HIP 11387 |
23.93 |
| 2026-08-05 12:00 |
02:28:52.12 |
-54:48:27.5 |
HIP 11387 |
24.32 |
| 2026-08-06 00:00 |
02:28:51.65 |
-54:49:08.4 |
HIP 11387 |
24.72 |
| 2026-08-06 12:00 |
02:28:51.13 |
-54:49:49.4 |
HIP 11387 |
25.13 |
| 2026-08-07 00:00 |
02:28:50.57 |
-54:50:30.4 |
HIP 11387 |
25.55 |
| 2026-08-07 12:00 |
02:28:49.97 |
-54:51:11.4 |
HIP 11387 |
25.97 |
| 2026-08-08 00:00 |
02:28:49.32 |
-54:51:52.5 |
HIP 11387 |
26.40 |
| 2026-08-08 12:00 |
02:28:48.63 |
-54:52:33.5 |
HIP 11387 |
26.83 |
| 2026-08-09 00:00 |
02:28:47.89 |
-54:53:14.6 |
HIP 11387 |
27.28 |
| 2026-08-09 12:00 |
02:28:47.11 |
-54:53:55.7 |
HIP 11387 |
27.73 |
| 2026-08-10 00:00 |
02:28:46.29 |
-54:54:36.8 |
HIP 11387 |
28.18 |
| 2026-08-10 12:00 |
02:28:45.42 |
-54:55:17.8 |
HIP 11387 |
28.64 |
| 2026-08-11 00:00 |
02:28:44.51 |
-54:55:58.9 |
HIP 11387 |
29.11 |
| 2026-08-11 12:00 |
02:28:43.55 |
-54:56:40.0 |
HIP 11387 |
29.58 |
| 2026-08-12 00:00 |
02:28:42.55 |
-54:57:21.0 |
HIP 11387 |
30.06 |
| 2026-08-12 12:00 |
02:28:41.50 |
-54:58:02.1 |
HIP 11387 |
30.54 |
| 2026-08-13 00:00 |
02:28:40.41 |
-54:58:43.1 |
HIP 11387 |
31.02 |
| 2026-08-13 12:00 |
02:28:39.28 |
-54:59:24.1 |
HIP 11387 |
31.51 |
| 2026-08-14 00:00 |
02:28:38.10 |
-55:00:05.1 |
HIP 11387 |
32.01 |
| 2026-08-14 12:00 |
02:28:36.88 |
-55:00:46.0 |
HIP 11387 |
32.51 |
| 2026-08-15 00:00 |
02:28:35.61 |
-55:01:26.9 |
HIP 11387 |
33.01 |
| 2026-08-15 12:00 |
02:28:34.30 |
-55:02:07.8 |
HIP 11387 |
33.52 |
| 2026-08-16 00:00 |
02:28:32.94 |
-55:02:48.7 |
HIP 11528 |
33.88 |
| 2026-08-16 12:00 |
02:28:31.54 |
-55:03:29.5 |
HIP 11528 |
33.20 |
| 2026-08-17 00:00 |
02:28:30.10 |
-55:04:10.2 |
HIP 11528 |
32.53 |
| 2026-08-17 12:00 |
02:28:28.61 |
-55:04:50.9 |
HIP 11528 |
31.86 |
| 2026-08-18 00:00 |
02:28:27.08 |
-55:05:31.5 |
HIP 11528 |
31.20 |
| 2026-08-18 12:00 |
02:28:25.50 |
-55:06:12.1 |
HIP 11528 |
30.54 |
| 2026-08-19 00:00 |
02:28:23.89 |
-55:06:52.7 |
HIP 11528 |
29.88 |