C/1997 A1 (NEAT)
| Parameter |
Value |
| Designation |
C/1997 A1 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1997-06-19T14:28:23.399040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:50Z |
| Obs used |
197 |
| NEO |
- |
| M1 |
9.500 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1997-03-14.0000000 |
| e |
1.00212808 |
| q (au) |
3.157173 |
| a (au) |
-1483.580380 |
| i (deg) |
145.071692 |
| Ω (om, deg) |
135.766697 |
| ω (w, deg) |
40.016058 |
| M (ma, deg) |
-0.001683 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.011 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.011 |
| n |
6.000 |
| 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) |
| 2026-02-03 00:00 |
20:44:29.72 |
-24:22:53.4 |
HIP 102290 |
22.50 |
| 2026-02-03 12:00 |
20:44:32.13 |
-24:22:45.9 |
HIP 102290 |
22.92 |
| 2026-02-04 00:00 |
20:44:34.54 |
-24:22:38.5 |
HIP 102290 |
23.34 |
| 2026-02-04 12:00 |
20:44:36.95 |
-24:22:31.1 |
HIP 102290 |
23.76 |
| 2026-02-05 00:00 |
20:44:39.35 |
-24:22:23.7 |
HIP 102290 |
24.19 |
| 2026-02-05 12:00 |
20:44:41.76 |
-24:22:16.4 |
HIP 102290 |
24.63 |
| 2026-02-06 00:00 |
20:44:44.16 |
-24:22:09.1 |
HIP 102290 |
25.07 |
| 2026-02-06 12:00 |
20:44:46.55 |
-24:22:01.8 |
HIP 102290 |
25.51 |
| 2026-02-07 00:00 |
20:44:48.95 |
-24:21:54.6 |
HIP 102290 |
25.95 |
| 2026-02-07 12:00 |
20:44:51.34 |
-24:21:47.5 |
HIP 102290 |
26.40 |
| 2026-02-08 00:00 |
20:44:53.72 |
-24:21:40.4 |
HIP 102290 |
26.85 |
| 2026-02-08 12:00 |
20:44:56.11 |
-24:21:33.3 |
HIP 102290 |
27.31 |
| 2026-02-09 00:00 |
20:44:58.49 |
-24:21:26.3 |
HIP 102290 |
27.77 |
| 2026-02-09 12:00 |
20:45:00.86 |
-24:21:19.3 |
HIP 102290 |
28.23 |
| 2026-02-10 00:00 |
20:45:03.23 |
-24:21:12.4 |
HIP 102290 |
28.69 |
| 2026-02-10 12:00 |
20:45:05.60 |
-24:21:05.5 |
HIP 102290 |
29.15 |
| 2026-02-11 00:00 |
20:45:07.96 |
-24:20:58.6 |
HIP 102290 |
29.61 |
| 2026-02-11 12:00 |
20:45:10.31 |
-24:20:51.8 |
HIP 102290 |
30.08 |
| 2026-02-12 00:00 |
20:45:12.66 |
-24:20:45.1 |
HIP 102290 |
30.55 |
| 2026-02-12 12:00 |
20:45:15.01 |
-24:20:38.4 |
HIP 102290 |
31.02 |
| 2026-02-13 00:00 |
20:45:17.35 |
-24:20:31.8 |
HIP 102290 |
31.49 |
| 2026-02-13 12:00 |
20:45:19.69 |
-24:20:25.2 |
HIP 102290 |
31.96 |
| 2026-02-14 00:00 |
20:45:22.02 |
-24:20:18.6 |
HIP 102290 |
32.43 |
| 2026-02-14 12:00 |
20:45:24.34 |
-24:20:12.2 |
HIP 102290 |
32.90 |
| 2026-02-15 00:00 |
20:45:26.66 |
-24:20:05.7 |
HIP 102290 |
33.37 |
| 2026-02-15 12:00 |
20:45:28.97 |
-24:19:59.3 |
HIP 102290 |
33.85 |
| 2026-02-16 00:00 |
20:45:31.27 |
-24:19:53.0 |
HIP 102290 |
34.32 |
| 2026-02-16 12:00 |
20:45:33.57 |
-24:19:46.7 |
HIP 102290 |
34.79 |
| 2026-02-17 00:00 |
20:45:35.86 |
-24:19:40.5 |
HIP 102290 |
35.26 |
| 2026-02-17 12:00 |
20:45:38.14 |
-24:19:34.4 |
HIP 102290 |
35.74 |
| 2026-02-18 00:00 |
20:45:40.42 |
-24:19:28.3 |
HIP 102290 |
36.21 |
| 2026-02-18 12:00 |
20:45:42.69 |
-24:19:22.2 |
HIP 102290 |
36.68 |
| 2026-02-19 00:00 |
20:45:44.95 |
-24:19:16.2 |
HIP 102494 |
36.56 |
| 2026-02-19 12:00 |
20:45:47.20 |
-24:19:10.3 |
HIP 102494 |
36.36 |
| 2026-02-20 00:00 |
20:45:49.45 |
-24:19:04.4 |
HIP 102494 |
36.17 |
| 2026-02-20 12:00 |
20:45:51.69 |
-24:18:58.6 |
HIP 102494 |
35.99 |
| 2026-02-21 00:00 |
20:45:53.91 |
-24:18:52.9 |
HIP 102494 |
35.82 |
| 2026-02-21 12:00 |
20:45:56.14 |
-24:18:47.2 |
HIP 102494 |
35.66 |
| 2026-02-22 00:00 |
20:45:58.35 |
-24:18:41.6 |
HIP 102494 |
35.50 |
| 2026-02-22 12:00 |
20:46:00.55 |
-24:18:36.0 |
HIP 102494 |
35.35 |
| 2026-02-23 00:00 |
20:46:02.74 |
-24:18:30.5 |
HIP 102494 |
35.21 |
| 2026-02-23 12:00 |
20:46:04.93 |
-24:18:25.1 |
HIP 102494 |
35.08 |
| 2026-02-24 00:00 |
20:46:07.11 |
-24:18:19.7 |
HIP 102494 |
34.96 |