| Parameter |
Value |
| Designation |
C/2002 A2 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2001-12-05T15:58:53.768640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:12Z |
| Obs used |
204 |
| NEO |
- |
| M1 |
7.500 |
| K1 |
12.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2002-04-19.0000000 |
| e |
0.72650481 |
| q (au) |
4.707082 |
| a (au) |
17.210839 |
| i (deg) |
14.054928 |
| Ω (om, deg) |
81.928817 |
| ω (w, deg) |
19.264638 |
| M (ma, deg) |
1.854331 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.536 + 5.031\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.536 |
| n |
5.031 |
| gf |
1.000 |
| gb |
-0.931 |
| 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 |
17:53:42.00 |
-25:42:38.0 |
HIP 87661 |
17.17 |
| 2026-07-29 12:00 |
17:53:38.51 |
-25:42:37.6 |
HIP 87661 |
17.56 |
| 2026-07-30 00:00 |
17:53:35.05 |
-25:42:37.2 |
HIP 87661 |
17.98 |
| 2026-07-30 12:00 |
17:53:31.61 |
-25:42:36.8 |
HIP 87661 |
18.41 |
| 2026-07-31 00:00 |
17:53:28.21 |
-25:42:36.3 |
HIP 87661 |
18.87 |
| 2026-07-31 12:00 |
17:53:24.83 |
-25:42:35.8 |
HIP 87661 |
19.34 |
| 2026-08-01 00:00 |
17:53:21.48 |
-25:42:35.4 |
HIP 87661 |
19.82 |
| 2026-08-01 12:00 |
17:53:18.16 |
-25:42:34.9 |
HIP 87422 |
19.10 |
| 2026-08-02 00:00 |
17:53:14.87 |
-25:42:34.4 |
HIP 87422 |
18.37 |
| 2026-08-02 12:00 |
17:53:11.61 |
-25:42:33.8 |
HIP 87422 |
17.66 |
| 2026-08-03 00:00 |
17:53:08.38 |
-25:42:33.3 |
HIP 87422 |
16.95 |
| 2026-08-03 12:00 |
17:53:05.18 |
-25:42:32.7 |
HIP 87422 |
16.25 |
| 2026-08-04 00:00 |
17:53:02.01 |
-25:42:32.1 |
HIP 87422 |
15.56 |
| 2026-08-04 12:00 |
17:52:58.87 |
-25:42:31.5 |
HIP 87422 |
14.88 |
| 2026-08-05 00:00 |
17:52:55.76 |
-25:42:30.9 |
HIP 87422 |
14.21 |
| 2026-08-05 12:00 |
17:52:52.69 |
-25:42:30.3 |
HIP 87422 |
13.54 |
| 2026-08-06 00:00 |
17:52:49.64 |
-25:42:29.6 |
HIP 87422 |
12.89 |
| 2026-08-06 12:00 |
17:52:46.62 |
-25:42:29.0 |
HIP 87422 |
12.25 |
| 2026-08-07 00:00 |
17:52:43.64 |
-25:42:28.3 |
HIP 87422 |
11.62 |
| 2026-08-07 12:00 |
17:52:40.69 |
-25:42:27.6 |
HIP 87422 |
11.00 |
| 2026-08-08 00:00 |
17:52:37.78 |
-25:42:26.9 |
HIP 87422 |
10.39 |
| 2026-08-08 12:00 |
17:52:34.89 |
-25:42:26.2 |
HIP 87422 |
9.80 |
| 2026-08-09 00:00 |
17:52:32.04 |
-25:42:25.4 |
HIP 87422 |
9.22 |
| 2026-08-09 12:00 |
17:52:29.22 |
-25:42:24.7 |
HIP 87422 |
8.66 |
| 2026-08-10 00:00 |
17:52:26.44 |
-25:42:24.0 |
HIP 87422 |
8.11 |
| 2026-08-10 12:00 |
17:52:23.69 |
-25:42:23.2 |
HIP 87422 |
7.58 |
| 2026-08-11 00:00 |
17:52:20.97 |
-25:42:22.4 |
HIP 87422 |
7.08 |
| 2026-08-11 12:00 |
17:52:18.29 |
-25:42:21.6 |
HIP 87422 |
6.60 |
| 2026-08-12 00:00 |
17:52:15.64 |
-25:42:20.8 |
HIP 87422 |
6.14 |
| 2026-08-12 12:00 |
17:52:13.03 |
-25:42:20.0 |
HIP 87422 |
5.72 |
| 2026-08-13 00:00 |
17:52:10.45 |
-25:42:19.2 |
HIP 87422 |
5.34 |
| 2026-08-13 12:00 |
17:52:07.91 |
-25:42:18.3 |
HIP 87422 |
4.99 |
| 2026-08-14 00:00 |
17:52:05.40 |
-25:42:17.5 |
HIP 87422 |
4.70 |
| 2026-08-14 12:00 |
17:52:02.93 |
-25:42:16.6 |
HIP 87422 |
4.47 |
| 2026-08-15 00:00 |
17:52:00.50 |
-25:42:15.8 |
HIP 87422 |
4.29 |
| 2026-08-15 12:00 |
17:51:58.10 |
-25:42:14.9 |
HIP 87422 |
4.18 |
| 2026-08-16 00:00 |
17:51:55.74 |
-25:42:14.0 |
HIP 87422 |
4.15 |
| 2026-08-16 12:00 |
17:51:53.41 |
-25:42:13.1 |
HIP 87422 |
4.17 |
| 2026-08-17 00:00 |
17:51:51.12 |
-25:42:12.2 |
HIP 87422 |
4.27 |
| 2026-08-17 12:00 |
17:51:48.87 |
-25:42:11.3 |
HIP 87422 |
4.41 |
| 2026-08-18 00:00 |
17:51:46.66 |
-25:42:10.4 |
HIP 87422 |
4.61 |
| 2026-08-18 12:00 |
17:51:44.48 |
-25:42:09.5 |
HIP 87422 |
4.84 |
| 2026-08-19 00:00 |
17:51:42.34 |
-25:42:08.5 |
HIP 87422 |
5.11 |