| 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) |
| 2026-03-26 00:00 |
12:34:59.18 |
-73:53:06.1 |
HIP 61440 |
11.43 |
| 2026-03-26 12:00 |
12:34:50.71 |
-73:53:05.7 |
HIP 61440 |
11.55 |
| 2026-03-27 00:00 |
12:34:42.22 |
-73:53:05.0 |
HIP 61440 |
11.70 |
| 2026-03-27 12:00 |
12:34:33.74 |
-73:53:03.9 |
HIP 61440 |
11.88 |
| 2026-03-28 00:00 |
12:34:25.25 |
-73:53:02.5 |
HIP 61440 |
12.09 |
| 2026-03-28 12:00 |
12:34:16.75 |
-73:53:00.7 |
HIP 61440 |
12.33 |
| 2026-03-29 00:00 |
12:34:08.26 |
-73:52:58.6 |
HIP 61440 |
12.60 |
| 2026-03-29 12:00 |
12:33:59.76 |
-73:52:56.2 |
HIP 61440 |
12.90 |
| 2026-03-30 00:00 |
12:33:51.26 |
-73:52:53.4 |
HIP 61440 |
13.22 |
| 2026-03-30 12:00 |
12:33:42.77 |
-73:52:50.3 |
HIP 61440 |
13.57 |
| 2026-03-31 00:00 |
12:33:34.27 |
-73:52:46.9 |
HIP 61216 |
13.92 |
| 2026-03-31 12:00 |
12:33:25.78 |
-73:52:43.1 |
HIP 61216 |
13.71 |
| 2026-04-01 00:00 |
12:33:17.28 |
-73:52:38.9 |
HIP 61216 |
13.52 |
| 2026-04-01 12:00 |
12:33:08.79 |
-73:52:34.5 |
HIP 61216 |
13.34 |
| 2026-04-02 00:00 |
12:33:00.31 |
-73:52:29.7 |
HIP 61216 |
13.19 |
| 2026-04-02 12:00 |
12:32:51.83 |
-73:52:24.5 |
HIP 61216 |
13.05 |
| 2026-04-03 00:00 |
12:32:43.35 |
-73:52:19.0 |
HIP 61216 |
12.94 |
| 2026-04-03 12:00 |
12:32:34.88 |
-73:52:13.2 |
HIP 61216 |
12.84 |
| 2026-04-04 00:00 |
12:32:26.42 |
-73:52:07.1 |
HIP 61216 |
12.77 |
| 2026-04-04 12:00 |
12:32:17.97 |
-73:52:00.6 |
HIP 61216 |
12.72 |
| 2026-04-05 00:00 |
12:32:09.52 |
-73:51:53.8 |
HIP 61216 |
12.69 |
| 2026-04-05 12:00 |
12:32:01.09 |
-73:51:46.6 |
HIP 61216 |
12.69 |
| 2026-04-06 00:00 |
12:31:52.66 |
-73:51:39.1 |
HIP 61216 |
12.71 |
| 2026-04-06 12:00 |
12:31:44.24 |
-73:51:31.3 |
HIP 61216 |
12.75 |
| 2026-04-07 00:00 |
12:31:35.84 |
-73:51:23.2 |
HIP 61216 |
12.81 |
| 2026-04-07 12:00 |
12:31:27.45 |
-73:51:14.7 |
HIP 61216 |
12.90 |
| 2026-04-08 00:00 |
12:31:19.07 |
-73:51:05.9 |
HIP 61216 |
13.01 |
| 2026-04-08 12:00 |
12:31:10.70 |
-73:50:56.8 |
HIP 61216 |
13.14 |
| 2026-04-09 00:00 |
12:31:02.35 |
-73:50:47.3 |
HIP 61216 |
13.29 |
| 2026-04-09 12:00 |
12:30:54.02 |
-73:50:37.5 |
HIP 61216 |
13.47 |
| 2026-04-10 00:00 |
12:30:45.70 |
-73:50:27.4 |
HIP 61216 |
13.66 |
| 2026-04-10 12:00 |
12:30:37.40 |
-73:50:17.0 |
HIP 61216 |
13.87 |
| 2026-04-11 00:00 |
12:30:29.11 |
-73:50:06.2 |
HIP 61216 |
14.10 |
| 2026-04-11 12:00 |
12:30:20.85 |
-73:49:55.2 |
HIP 61216 |
14.35 |
| 2026-04-12 00:00 |
12:30:12.60 |
-73:49:43.8 |
HIP 61216 |
14.61 |
| 2026-04-12 12:00 |
12:30:04.37 |
-73:49:32.0 |
HIP 61216 |
14.89 |
| 2026-04-13 00:00 |
12:29:56.16 |
-73:49:20.0 |
HIP 61216 |
15.18 |
| 2026-04-13 12:00 |
12:29:47.98 |
-73:49:07.6 |
HIP 61216 |
15.49 |
| 2026-04-14 00:00 |
12:29:39.82 |
-73:48:55.0 |
HIP 61216 |
15.81 |
| 2026-04-14 12:00 |
12:29:31.68 |
-73:48:42.0 |
HIP 61216 |
16.15 |
| 2026-04-15 00:00 |
12:29:23.56 |
-73:48:28.7 |
HIP 61216 |
16.49 |
| 2026-04-15 12:00 |
12:29:15.47 |
-73:48:15.0 |
HIP 61216 |
16.85 |
| 2026-04-16 00:00 |
12:29:07.40 |
-73:48:01.1 |
HIP 61216 |
17.21 |