C/2001 A1 (LINEAR)
| Parameter |
Value |
| Designation |
C/2001 A1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2000-09-17T14:53:00.830400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:08Z |
| Obs used |
126 |
| NEO |
- |
| M1 |
12.800 |
| K1 |
6.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2001-02-04.0000000 |
| e |
0.99093655 |
| q (au) |
2.406447 |
| a (au) |
265.511207 |
| i (deg) |
59.940739 |
| Ω (om, deg) |
339.594496 |
| ω (w, deg) |
107.889040 |
| M (ma, deg) |
0.031753 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.703 + 3.720\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.703 |
| n |
3.720 |
| gf |
1.000 |
| gb |
-0.555 |
| k |
0.800 |
| 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) |
| 2026-02-03 00:00 |
12:46:38.63 |
-73:25:26.8 |
HIP 62243 |
22.99 |
| 2026-02-03 12:00 |
12:46:34.44 |
-73:25:57.1 |
HIP 62243 |
22.43 |
| 2026-02-04 00:00 |
12:46:30.17 |
-73:26:27.2 |
HIP 62243 |
21.88 |
| 2026-02-04 12:00 |
12:46:25.84 |
-73:26:57.0 |
HIP 62243 |
21.32 |
| 2026-02-05 00:00 |
12:46:21.44 |
-73:27:26.7 |
HIP 62243 |
20.78 |
| 2026-02-05 12:00 |
12:46:16.97 |
-73:27:56.1 |
HIP 62243 |
20.24 |
| 2026-02-06 00:00 |
12:46:12.44 |
-73:28:25.3 |
HIP 62243 |
19.70 |
| 2026-02-06 12:00 |
12:46:07.84 |
-73:28:54.3 |
HIP 62243 |
19.17 |
| 2026-02-07 00:00 |
12:46:03.17 |
-73:29:23.1 |
HIP 62243 |
18.64 |
| 2026-02-07 12:00 |
12:45:58.44 |
-73:29:51.6 |
HIP 62243 |
18.13 |
| 2026-02-08 00:00 |
12:45:53.64 |
-73:30:19.9 |
HIP 62243 |
17.61 |
| 2026-02-08 12:00 |
12:45:48.77 |
-73:30:48.0 |
HIP 62243 |
17.11 |
| 2026-02-09 00:00 |
12:45:43.85 |
-73:31:15.9 |
HIP 62243 |
16.62 |
| 2026-02-09 12:00 |
12:45:38.85 |
-73:31:43.5 |
HIP 62243 |
16.13 |
| 2026-02-10 00:00 |
12:45:33.79 |
-73:32:10.8 |
HIP 62243 |
15.66 |
| 2026-02-10 12:00 |
12:45:28.67 |
-73:32:37.9 |
HIP 62243 |
15.19 |
| 2026-02-11 00:00 |
12:45:23.48 |
-73:33:04.8 |
HIP 62243 |
14.74 |
| 2026-02-11 12:00 |
12:45:18.23 |
-73:33:31.4 |
HIP 62243 |
14.30 |
| 2026-02-12 00:00 |
12:45:12.92 |
-73:33:57.8 |
HIP 62243 |
13.88 |
| 2026-02-12 12:00 |
12:45:07.54 |
-73:34:23.9 |
HIP 62243 |
13.47 |
| 2026-02-13 00:00 |
12:45:02.11 |
-73:34:49.8 |
HIP 62243 |
13.08 |
| 2026-02-13 12:00 |
12:44:56.61 |
-73:35:15.4 |
HIP 62243 |
12.71 |
| 2026-02-14 00:00 |
12:44:51.05 |
-73:35:40.8 |
HIP 62243 |
12.36 |
| 2026-02-14 12:00 |
12:44:45.42 |
-73:36:05.8 |
HIP 62243 |
12.03 |
| 2026-02-15 00:00 |
12:44:39.74 |
-73:36:30.7 |
HIP 62243 |
11.72 |
| 2026-02-15 12:00 |
12:44:34.00 |
-73:36:55.2 |
HIP 62243 |
11.45 |
| 2026-02-16 00:00 |
12:44:28.20 |
-73:37:19.5 |
HIP 62243 |
11.20 |
| 2026-02-16 12:00 |
12:44:22.34 |
-73:37:43.6 |
HIP 62243 |
10.98 |
| 2026-02-17 00:00 |
12:44:16.42 |
-73:38:07.3 |
HIP 62243 |
10.79 |
| 2026-02-17 12:00 |
12:44:10.44 |
-73:38:30.8 |
HIP 62243 |
10.63 |
| 2026-02-18 00:00 |
12:44:04.40 |
-73:38:54.0 |
HIP 62243 |
10.51 |
| 2026-02-18 12:00 |
12:43:58.31 |
-73:39:16.9 |
HIP 62243 |
10.43 |
| 2026-02-19 00:00 |
12:43:52.16 |
-73:39:39.6 |
HIP 62243 |
10.38 |
| 2026-02-19 12:00 |
12:43:45.96 |
-73:40:01.9 |
HIP 62243 |
10.37 |
| 2026-02-20 00:00 |
12:43:39.70 |
-73:40:24.0 |
HIP 62243 |
10.40 |
| 2026-02-20 12:00 |
12:43:33.39 |
-73:40:45.8 |
HIP 62243 |
10.47 |
| 2026-02-21 00:00 |
12:43:27.02 |
-73:41:07.3 |
HIP 62243 |
10.57 |
| 2026-02-21 12:00 |
12:43:20.59 |
-73:41:28.5 |
HIP 62243 |
10.70 |
| 2026-02-22 00:00 |
12:43:14.12 |
-73:41:49.4 |
HIP 62243 |
10.87 |
| 2026-02-22 12:00 |
12:43:07.59 |
-73:42:10.0 |
HIP 62243 |
11.08 |
| 2026-02-23 00:00 |
12:43:01.01 |
-73:42:30.4 |
HIP 62243 |
11.31 |
| 2026-02-23 12:00 |
12:42:54.38 |
-73:42:50.4 |
HIP 62243 |
11.57 |
| 2026-02-24 00:00 |
12:42:47.70 |
-73:43:10.2 |
HIP 62243 |
11.86 |