| Parameter |
Value |
| Designation |
C/2001 Q1 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2001-09-20T20:53:33.852480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:10Z |
| Obs used |
77 |
| NEO |
- |
| M1 |
11.900 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2001-09-28.0000000 |
| e |
0.96593590 |
| q (au) |
5.833970 |
| a (au) |
171.264460 |
| i (deg) |
66.950479 |
| Ω (om, deg) |
139.261335 |
| ω (w, deg) |
175.461635 |
| M (ma, deg) |
0.003135 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.306 + 3.356\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.306 |
| n |
3.356 |
| gf |
0.883 |
| gb |
-0.935 |
| k |
1.000 |
| δ90 |
4.130 |
| 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 |
07:30:40.37 |
-19:44:11.5 |
HIP 36452 |
15.48 |
| 2026-09-20 12:00 |
07:30:41.68 |
-19:44:36.6 |
HIP 36452 |
16.00 |
| 2026-09-21 00:00 |
07:30:42.97 |
-19:45:01.7 |
HIP 36452 |
16.51 |
| 2026-09-21 12:00 |
07:30:44.23 |
-19:45:26.9 |
HIP 36452 |
17.03 |
| 2026-09-22 00:00 |
07:30:45.47 |
-19:45:52.2 |
HIP 36452 |
17.54 |
| 2026-09-22 12:00 |
07:30:46.69 |
-19:46:17.5 |
HIP 36452 |
18.05 |
| 2026-09-23 00:00 |
07:30:47.89 |
-19:46:42.8 |
HIP 36452 |
18.56 |
| 2026-09-23 12:00 |
07:30:49.06 |
-19:47:08.2 |
HIP 36452 |
19.06 |
| 2026-09-24 00:00 |
07:30:50.21 |
-19:47:33.7 |
HIP 36586 |
19.33 |
| 2026-09-24 12:00 |
07:30:51.33 |
-19:47:59.2 |
HIP 36586 |
19.58 |
| 2026-09-25 00:00 |
07:30:52.43 |
-19:48:24.8 |
HIP 36586 |
19.84 |
| 2026-09-25 12:00 |
07:30:53.51 |
-19:48:50.4 |
HIP 36586 |
20.11 |
| 2026-09-26 00:00 |
07:30:54.57 |
-19:49:16.0 |
HIP 36586 |
20.39 |
| 2026-09-26 12:00 |
07:30:55.60 |
-19:49:41.7 |
HIP 36586 |
20.69 |
| 2026-09-27 00:00 |
07:30:56.60 |
-19:50:07.5 |
HIP 36586 |
20.99 |
| 2026-09-27 12:00 |
07:30:57.59 |
-19:50:33.2 |
HIP 36586 |
21.30 |
| 2026-09-28 00:00 |
07:30:58.55 |
-19:50:59.0 |
HIP 36617 |
21.56 |
| 2026-09-28 12:00 |
07:30:59.48 |
-19:51:24.9 |
HIP 36617 |
21.08 |
| 2026-09-29 00:00 |
07:31:00.40 |
-19:51:50.7 |
HIP 36617 |
20.60 |
| 2026-09-29 12:00 |
07:31:01.28 |
-19:52:16.6 |
HIP 36617 |
20.13 |
| 2026-09-30 00:00 |
07:31:02.15 |
-19:52:42.6 |
HIP 36617 |
19.66 |
| 2026-09-30 12:00 |
07:31:02.99 |
-19:53:08.5 |
HIP 36617 |
19.19 |
| 2026-10-01 00:00 |
07:31:03.80 |
-19:53:34.5 |
HIP 36617 |
18.72 |
| 2026-10-01 12:00 |
07:31:04.59 |
-19:54:00.5 |
HIP 36617 |
18.26 |
| 2026-10-02 00:00 |
07:31:05.36 |
-19:54:26.5 |
HIP 36617 |
17.80 |
| 2026-10-02 12:00 |
07:31:06.10 |
-19:54:52.5 |
HIP 36617 |
17.35 |
| 2026-10-03 00:00 |
07:31:06.81 |
-19:55:18.6 |
HIP 36617 |
16.90 |
| 2026-10-03 12:00 |
07:31:07.51 |
-19:55:44.7 |
HIP 36617 |
16.45 |
| 2026-10-04 00:00 |
07:31:08.17 |
-19:56:10.8 |
HIP 36617 |
16.01 |
| 2026-10-04 12:00 |
07:31:08.82 |
-19:56:36.9 |
HIP 36617 |
15.57 |
| 2026-10-05 00:00 |
07:31:09.43 |
-19:57:03.0 |
HIP 36617 |
15.14 |
| 2026-10-05 12:00 |
07:31:10.03 |
-19:57:29.1 |
HIP 36617 |
14.71 |
| 2026-10-06 00:00 |
07:31:10.59 |
-19:57:55.2 |
HIP 36617 |
14.29 |
| 2026-10-06 12:00 |
07:31:11.13 |
-19:58:21.3 |
HIP 36617 |
13.87 |
| 2026-10-07 00:00 |
07:31:11.65 |
-19:58:47.4 |
HIP 36617 |
13.46 |
| 2026-10-07 12:00 |
07:31:12.14 |
-19:59:13.5 |
HIP 36617 |
13.05 |
| 2026-10-08 00:00 |
07:31:12.61 |
-19:59:39.7 |
HIP 36617 |
12.66 |
| 2026-10-08 12:00 |
07:31:13.05 |
-20:00:05.8 |
HIP 36617 |
12.27 |
| 2026-10-09 00:00 |
07:31:13.46 |
-20:00:31.9 |
HIP 36617 |
11.89 |
| 2026-10-09 12:00 |
07:31:13.85 |
-20:00:57.9 |
HIP 36617 |
11.52 |
| 2026-10-10 00:00 |
07:31:14.22 |
-20:01:24.0 |
HIP 36617 |
11.16 |
| 2026-10-10 12:00 |
07:31:14.56 |
-20:01:50.1 |
HIP 36617 |
10.81 |
| 2026-10-11 00:00 |
07:31:14.87 |
-20:02:16.1 |
HIP 36617 |
10.47 |