| 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) |
| 2026-06-01 00:00 |
20:47:57.66 |
-24:25:45.0 |
HIP 102822 |
34.57 |
| 2026-06-01 12:00 |
20:47:56.31 |
-24:25:54.6 |
HIP 102822 |
34.69 |
| 2026-06-02 00:00 |
20:47:54.94 |
-24:26:04.2 |
HIP 102516 |
34.44 |
| 2026-06-02 12:00 |
20:47:53.55 |
-24:26:13.9 |
HIP 102516 |
34.13 |
| 2026-06-03 00:00 |
20:47:52.14 |
-24:26:23.7 |
HIP 102516 |
33.82 |
| 2026-06-03 12:00 |
20:47:50.72 |
-24:26:33.5 |
HIP 102516 |
33.51 |
| 2026-06-04 00:00 |
20:47:49.28 |
-24:26:43.3 |
HIP 102516 |
33.20 |
| 2026-06-04 12:00 |
20:47:47.82 |
-24:26:53.2 |
HIP 102516 |
32.88 |
| 2026-06-05 00:00 |
20:47:46.34 |
-24:27:03.2 |
HIP 102516 |
32.57 |
| 2026-06-05 12:00 |
20:47:44.84 |
-24:27:13.2 |
HIP 102516 |
32.25 |
| 2026-06-06 00:00 |
20:47:43.33 |
-24:27:23.2 |
HIP 102516 |
31.93 |
| 2026-06-06 12:00 |
20:47:41.80 |
-24:27:33.3 |
HIP 102516 |
31.61 |
| 2026-06-07 00:00 |
20:47:40.25 |
-24:27:43.4 |
HIP 102516 |
31.28 |
| 2026-06-07 12:00 |
20:47:38.68 |
-24:27:53.6 |
HIP 102516 |
30.96 |
| 2026-06-08 00:00 |
20:47:37.10 |
-24:28:03.8 |
HIP 102516 |
30.64 |
| 2026-06-08 12:00 |
20:47:35.49 |
-24:28:14.1 |
HIP 102516 |
30.31 |
| 2026-06-09 00:00 |
20:47:33.88 |
-24:28:24.4 |
HIP 102516 |
29.99 |
| 2026-06-09 12:00 |
20:47:32.24 |
-24:28:34.7 |
HIP 102516 |
29.66 |
| 2026-06-10 00:00 |
20:47:30.59 |
-24:28:45.1 |
HIP 102516 |
29.33 |
| 2026-06-10 12:00 |
20:47:28.92 |
-24:28:55.6 |
HIP 102516 |
29.01 |
| 2026-06-11 00:00 |
20:47:27.23 |
-24:29:06.0 |
HIP 102516 |
28.68 |
| 2026-06-11 12:00 |
20:47:25.53 |
-24:29:16.5 |
HIP 102516 |
28.35 |
| 2026-06-12 00:00 |
20:47:23.81 |
-24:29:27.1 |
HIP 102516 |
28.03 |
| 2026-06-12 12:00 |
20:47:22.08 |
-24:29:37.7 |
HIP 102516 |
27.70 |
| 2026-06-13 00:00 |
20:47:20.33 |
-24:29:48.3 |
HIP 102516 |
27.38 |
| 2026-06-13 12:00 |
20:47:18.56 |
-24:29:59.0 |
HIP 102516 |
27.06 |
| 2026-06-14 00:00 |
20:47:16.77 |
-24:30:09.6 |
HIP 102516 |
26.73 |
| 2026-06-14 12:00 |
20:47:14.97 |
-24:30:20.4 |
HIP 102516 |
26.41 |
| 2026-06-15 00:00 |
20:47:13.16 |
-24:30:31.1 |
HIP 102516 |
26.10 |
| 2026-06-15 12:00 |
20:47:11.33 |
-24:30:41.9 |
HIP 102516 |
25.78 |
| 2026-06-16 00:00 |
20:47:09.48 |
-24:30:52.8 |
HIP 102516 |
25.47 |
| 2026-06-16 12:00 |
20:47:07.62 |
-24:31:03.6 |
HIP 102516 |
25.16 |
| 2026-06-17 00:00 |
20:47:05.74 |
-24:31:14.5 |
HIP 102516 |
24.85 |
| 2026-06-17 12:00 |
20:47:03.85 |
-24:31:25.4 |
HIP 102516 |
24.55 |
| 2026-06-18 00:00 |
20:47:01.94 |
-24:31:36.4 |
HIP 102516 |
24.24 |
| 2026-06-18 12:00 |
20:47:00.02 |
-24:31:47.4 |
HIP 102516 |
23.95 |
| 2026-06-19 00:00 |
20:46:58.08 |
-24:31:58.4 |
HIP 102516 |
23.66 |
| 2026-06-19 12:00 |
20:46:56.13 |
-24:32:09.4 |
HIP 102516 |
23.37 |
| 2026-06-20 00:00 |
20:46:54.16 |
-24:32:20.5 |
HIP 102516 |
23.09 |
| 2026-06-20 12:00 |
20:46:52.18 |
-24:32:31.6 |
HIP 102516 |
22.81 |
| 2026-06-21 00:00 |
20:46:50.19 |
-24:32:42.7 |
HIP 102516 |
22.54 |
| 2026-06-21 12:00 |
20:46:48.18 |
-24:32:53.8 |
HIP 102516 |
22.28 |
| 2026-06-22 00:00 |
20:46:46.16 |
-24:33:05.0 |
HIP 102516 |
22.02 |