| Parameter |
Value |
| Designation |
327P/Van Ness |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2022-09-02T13:33:36.086400Z |
| Orbit solution date (soln_date, UTC) |
2024-06-21T13:42:21Z |
| Obs used |
900 |
| NEO |
- |
| M1 |
14.800 |
| K1 |
11.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-09-26.0000000 |
| e |
0.56283038 |
| q (au) |
1.557541 |
| a (au) |
3.562783 |
| i (deg) |
36.245156 |
| Ω (om, deg) |
173.974419 |
| ω (w, deg) |
185.022025 |
| M (ma, deg) |
256.444765 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.825 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.825 |
| n |
6.000 |
| gf |
0.995 |
| gb |
-0.647 |
| k |
0.800 |
| δ90 |
2.043 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2020-05-30 |
2022-09-02 |
-11.8557 |
+2.478 |
| 2022-09-03 |
2023-01-20 |
-0.5923 |
+0.111 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
12:38:11.88 |
+05:26:21.4 |
HIP 61793 |
25.40 |
| 2026-09-20 12:00 |
12:38:33.77 |
+05:24:43.0 |
HIP 61793 |
20.06 |
| 2026-09-21 00:00 |
12:38:55.69 |
+05:23:04.6 |
HIP 61793 |
14.96 |
| 2026-09-21 12:00 |
12:39:17.63 |
+05:21:26.4 |
HIP 61793 |
10.48 |
| 2026-09-22 00:00 |
12:39:39.60 |
+05:19:48.4 |
HIP 61793 |
7.81 |
| 2026-09-22 12:00 |
12:40:01.60 |
+05:18:10.5 |
HIP 61793 |
8.78 |
| 2026-09-23 00:00 |
12:40:23.62 |
+05:16:32.8 |
HIP 61793 |
12.59 |
| 2026-09-23 12:00 |
12:40:45.66 |
+05:14:55.2 |
HIP 61793 |
17.48 |
| 2026-09-24 00:00 |
12:41:07.73 |
+05:13:17.9 |
HIP 61970 |
17.30 |
| 2026-09-24 12:00 |
12:41:29.83 |
+05:11:40.7 |
HIP 61970 |
15.16 |
| 2026-09-25 00:00 |
12:41:51.95 |
+05:10:03.7 |
HIP 61970 |
15.04 |
| 2026-09-25 12:00 |
12:42:14.09 |
+05:08:26.8 |
HIP 62034 |
12.76 |
| 2026-09-26 00:00 |
12:42:36.25 |
+05:06:50.2 |
HIP 62034 |
10.33 |
| 2026-09-26 12:00 |
12:42:58.43 |
+05:05:13.8 |
HIP 62034 |
10.80 |
| 2026-09-27 00:00 |
12:43:20.64 |
+05:03:37.5 |
HIP 62034 |
13.88 |
| 2026-09-27 12:00 |
12:43:42.86 |
+05:02:01.5 |
HIP 62034 |
18.30 |
| 2026-09-28 00:00 |
12:44:05.11 |
+05:00:25.7 |
HIP 62034 |
23.32 |
| 2026-09-28 12:00 |
12:44:27.38 |
+04:58:50.1 |
HIP 62034 |
28.62 |
| 2026-09-29 00:00 |
12:44:49.66 |
+04:57:14.7 |
HIP 62034 |
34.07 |
| 2026-09-29 12:00 |
12:45:11.97 |
+04:55:39.6 |
HIP 62240 |
34.15 |
| 2026-09-30 00:00 |
12:45:34.29 |
+04:54:04.6 |
HIP 62240 |
32.56 |
| 2026-09-30 12:00 |
12:45:56.63 |
+04:52:30.0 |
HIP 62240 |
31.97 |
| 2026-10-01 00:00 |
12:46:18.99 |
+04:50:55.5 |
HIP 62477 |
30.85 |
| 2026-10-01 12:00 |
12:46:41.37 |
+04:49:21.3 |
HIP 62477 |
26.46 |
| 2026-10-02 00:00 |
12:47:03.76 |
+04:47:47.4 |
HIP 62477 |
22.71 |
| 2026-10-02 12:00 |
12:47:26.17 |
+04:46:13.7 |
HIP 62477 |
19.94 |
| 2026-10-03 00:00 |
12:47:48.59 |
+04:44:40.3 |
HIP 62477 |
18.63 |
| 2026-10-03 12:00 |
12:48:11.03 |
+04:43:07.2 |
HIP 62477 |
19.06 |
| 2026-10-04 00:00 |
12:48:33.48 |
+04:41:34.3 |
HIP 62477 |
21.13 |
| 2026-10-04 12:00 |
12:48:55.95 |
+04:40:01.7 |
HIP 62477 |
24.44 |
| 2026-10-05 00:00 |
12:49:18.43 |
+04:38:29.4 |
HIP 62477 |
28.55 |
| 2026-10-05 12:00 |
12:49:40.92 |
+04:36:57.4 |
HIP 62477 |
33.17 |
| 2026-10-06 00:00 |
12:50:03.42 |
+04:35:25.7 |
HIP 62585 |
36.07 |
| 2026-10-06 12:00 |
12:50:25.94 |
+04:33:54.4 |
HIP 62585 |
39.28 |
| 2026-10-07 00:00 |
12:50:48.47 |
+04:32:23.3 |
HIP 62585 |
43.03 |
| 2026-10-07 12:00 |
12:51:11.00 |
+04:30:52.5 |
HIP 62917 |
40.72 |
| 2026-10-08 00:00 |
12:51:33.55 |
+04:29:22.1 |
HIP 62917 |
34.98 |
| 2026-10-08 12:00 |
12:51:56.10 |
+04:27:52.0 |
HIP 62917 |
29.28 |
| 2026-10-09 00:00 |
12:52:18.67 |
+04:26:22.3 |
HIP 62917 |
23.64 |
| 2026-10-09 12:00 |
12:52:41.24 |
+04:24:52.9 |
HIP 62917 |
18.12 |
| 2026-10-10 00:00 |
12:53:03.81 |
+04:23:23.8 |
HIP 62917 |
12.86 |
| 2026-10-10 12:00 |
12:53:26.40 |
+04:21:55.1 |
HIP 62917 |
8.38 |
| 2026-10-11 00:00 |
12:53:48.99 |
+04:20:26.8 |
HIP 62917 |
6.56 |