| 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) |
| 2026-03-26 00:00 |
20:47:55.22 |
-24:15:08.4 |
HIP 102494 |
38.88 |
| 2026-03-26 12:00 |
20:47:56.57 |
-24:15:07.6 |
HIP 102494 |
39.05 |
| 2026-03-27 00:00 |
20:47:57.89 |
-24:15:06.9 |
HIP 102494 |
39.21 |
| 2026-03-27 12:00 |
20:47:59.20 |
-24:15:06.3 |
HIP 102494 |
39.38 |
| 2026-03-28 00:00 |
20:48:00.49 |
-24:15:05.8 |
HIP 102494 |
39.55 |
| 2026-03-28 12:00 |
20:48:01.76 |
-24:15:05.4 |
HIP 102494 |
39.72 |
| 2026-03-29 00:00 |
20:48:03.02 |
-24:15:05.1 |
HIP 102494 |
39.89 |
| 2026-03-29 12:00 |
20:48:04.25 |
-24:15:04.8 |
HIP 102494 |
40.06 |
| 2026-03-30 00:00 |
20:48:05.47 |
-24:15:04.6 |
HIP 102494 |
40.23 |
| 2026-03-30 12:00 |
20:48:06.67 |
-24:15:04.5 |
HIP 102494 |
40.40 |
| 2026-03-31 00:00 |
20:48:07.85 |
-24:15:04.5 |
HIP 102494 |
40.57 |
| 2026-03-31 12:00 |
20:48:09.01 |
-24:15:04.6 |
HIP 102494 |
40.73 |
| 2026-04-01 00:00 |
20:48:10.16 |
-24:15:04.8 |
HIP 102494 |
40.90 |
| 2026-04-01 12:00 |
20:48:11.29 |
-24:15:05.0 |
HIP 102822 |
40.80 |
| 2026-04-02 00:00 |
20:48:12.40 |
-24:15:05.4 |
HIP 102822 |
40.66 |
| 2026-04-02 12:00 |
20:48:13.48 |
-24:15:05.8 |
HIP 102822 |
40.52 |
| 2026-04-03 00:00 |
20:48:14.56 |
-24:15:06.3 |
HIP 102822 |
40.38 |
| 2026-04-03 12:00 |
20:48:15.61 |
-24:15:06.9 |
HIP 102822 |
40.25 |
| 2026-04-04 00:00 |
20:48:16.64 |
-24:15:07.6 |
HIP 102822 |
40.11 |
| 2026-04-04 12:00 |
20:48:17.66 |
-24:15:08.4 |
HIP 102822 |
39.98 |
| 2026-04-05 00:00 |
20:48:18.65 |
-24:15:09.2 |
HIP 102822 |
39.85 |
| 2026-04-05 12:00 |
20:48:19.63 |
-24:15:10.2 |
HIP 102822 |
39.72 |
| 2026-04-06 00:00 |
20:48:20.59 |
-24:15:11.2 |
HIP 102822 |
39.60 |
| 2026-04-06 12:00 |
20:48:21.52 |
-24:15:12.3 |
HIP 102822 |
39.47 |
| 2026-04-07 00:00 |
20:48:22.44 |
-24:15:13.5 |
HIP 102822 |
39.35 |
| 2026-04-07 12:00 |
20:48:23.34 |
-24:15:14.8 |
HIP 102822 |
39.23 |
| 2026-04-08 00:00 |
20:48:24.22 |
-24:15:16.2 |
HIP 102822 |
39.11 |
| 2026-04-08 12:00 |
20:48:25.08 |
-24:15:17.7 |
HIP 102822 |
39.00 |
| 2026-04-09 00:00 |
20:48:25.93 |
-24:15:19.2 |
HIP 102822 |
38.88 |
| 2026-04-09 12:00 |
20:48:26.75 |
-24:15:20.9 |
HIP 102822 |
38.77 |
| 2026-04-10 00:00 |
20:48:27.55 |
-24:15:22.6 |
HIP 102822 |
38.65 |
| 2026-04-10 12:00 |
20:48:28.33 |
-24:15:24.4 |
HIP 102822 |
38.54 |
| 2026-04-11 00:00 |
20:48:29.09 |
-24:15:26.3 |
HIP 102822 |
38.43 |
| 2026-04-11 12:00 |
20:48:29.83 |
-24:15:28.3 |
HIP 102822 |
38.32 |
| 2026-04-12 00:00 |
20:48:30.56 |
-24:15:30.4 |
HIP 102822 |
38.21 |
| 2026-04-12 12:00 |
20:48:31.26 |
-24:15:32.5 |
HIP 102822 |
38.11 |
| 2026-04-13 00:00 |
20:48:31.94 |
-24:15:34.8 |
HIP 102822 |
38.00 |
| 2026-04-13 12:00 |
20:48:32.60 |
-24:15:37.1 |
HIP 102822 |
37.90 |
| 2026-04-14 00:00 |
20:48:33.24 |
-24:15:39.5 |
HIP 102822 |
37.80 |
| 2026-04-14 12:00 |
20:48:33.86 |
-24:15:42.0 |
HIP 102822 |
37.70 |
| 2026-04-15 00:00 |
20:48:34.46 |
-24:15:44.6 |
HIP 102822 |
37.59 |
| 2026-04-15 12:00 |
20:48:35.04 |
-24:15:47.3 |
HIP 102822 |
37.50 |
| 2026-04-16 00:00 |
20:48:35.60 |
-24:15:50.1 |
HIP 102822 |
37.40 |