| 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
$$
M_a = (14.824 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.824 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-0.648 |
| k |
0.800 |
| δ90 |
2.020 |
| 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 |
-11.8540 |
+2.478 |
| 2022-09-03 |
2023-01-20 |
-0.5936 |
+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) |
| 2026-05-12 00:00 |
11:49:53.58 |
+09:03:03.5 |
HIP 57755 |
30.24 |
| 2026-05-12 12:00 |
11:49:46.83 |
+09:04:12.8 |
HIP 57755 |
29.87 |
| 2026-05-13 00:00 |
11:49:40.26 |
+09:05:20.7 |
HIP 57755 |
29.65 |
| 2026-05-13 12:00 |
11:49:33.84 |
+09:06:27.2 |
HIP 57755 |
29.55 |
| 2026-05-14 00:00 |
11:49:27.60 |
+09:07:32.3 |
HIP 57755 |
29.57 |
| 2026-05-14 12:00 |
11:49:21.53 |
+09:08:36.0 |
HIP 57755 |
29.69 |
| 2026-05-15 00:00 |
11:49:15.63 |
+09:09:38.3 |
HIP 57755 |
29.92 |
| 2026-05-15 12:00 |
11:49:09.90 |
+09:10:39.3 |
HIP 57755 |
30.24 |
| 2026-05-16 00:00 |
11:49:04.34 |
+09:11:38.8 |
HIP 57755 |
30.63 |
| 2026-05-16 12:00 |
11:48:58.95 |
+09:12:37.0 |
HIP 57501 |
30.92 |
| 2026-05-17 00:00 |
11:48:53.74 |
+09:13:33.7 |
HIP 57501 |
29.34 |
| 2026-05-17 12:00 |
11:48:48.70 |
+09:14:29.1 |
HIP 57501 |
27.80 |
| 2026-05-18 00:00 |
11:48:43.82 |
+09:15:23.1 |
HIP 57501 |
26.31 |
| 2026-05-18 12:00 |
11:48:39.13 |
+09:16:15.7 |
HIP 57501 |
24.87 |
| 2026-05-19 00:00 |
11:48:34.60 |
+09:17:07.0 |
HIP 57501 |
23.48 |
| 2026-05-19 12:00 |
11:48:30.25 |
+09:17:56.9 |
HIP 57501 |
22.14 |
| 2026-05-20 00:00 |
11:48:26.07 |
+09:18:45.4 |
HIP 57501 |
20.86 |
| 2026-05-20 12:00 |
11:48:22.07 |
+09:19:32.5 |
HIP 57501 |
19.62 |
| 2026-05-21 00:00 |
11:48:18.24 |
+09:20:18.3 |
HIP 57501 |
18.44 |
| 2026-05-21 12:00 |
11:48:14.58 |
+09:21:02.8 |
HIP 57501 |
17.31 |
| 2026-05-22 00:00 |
11:48:11.09 |
+09:21:45.9 |
HIP 57501 |
16.23 |
| 2026-05-22 12:00 |
11:48:07.78 |
+09:22:27.7 |
HIP 57501 |
15.21 |
| 2026-05-23 00:00 |
11:48:04.64 |
+09:23:08.1 |
HIP 57501 |
14.24 |
| 2026-05-23 12:00 |
11:48:01.68 |
+09:23:47.2 |
HIP 57501 |
13.33 |
| 2026-05-24 00:00 |
11:47:58.88 |
+09:24:24.9 |
HIP 57501 |
12.48 |
| 2026-05-24 12:00 |
11:47:56.26 |
+09:25:01.4 |
HIP 57501 |
11.68 |
| 2026-05-25 00:00 |
11:47:53.81 |
+09:25:36.5 |
HIP 57501 |
10.95 |
| 2026-05-25 12:00 |
11:47:51.54 |
+09:26:10.4 |
HIP 57501 |
10.28 |
| 2026-05-26 00:00 |
11:47:49.43 |
+09:26:42.9 |
HIP 57501 |
9.67 |
| 2026-05-26 12:00 |
11:47:47.50 |
+09:27:14.1 |
HIP 57501 |
9.13 |
| 2026-05-27 00:00 |
11:47:45.74 |
+09:27:44.1 |
HIP 57501 |
8.66 |
| 2026-05-27 12:00 |
11:47:44.15 |
+09:28:12.8 |
HIP 57501 |
8.25 |
| 2026-05-28 00:00 |
11:47:42.73 |
+09:28:40.1 |
HIP 57501 |
7.92 |
| 2026-05-28 12:00 |
11:47:41.48 |
+09:29:06.3 |
HIP 57501 |
7.65 |
| 2026-05-29 00:00 |
11:47:40.40 |
+09:29:31.1 |
HIP 57501 |
7.45 |
| 2026-05-29 12:00 |
11:47:39.49 |
+09:29:54.7 |
HIP 57501 |
7.31 |
| 2026-05-30 00:00 |
11:47:38.75 |
+09:30:17.0 |
HIP 57501 |
7.23 |
| 2026-05-30 12:00 |
11:47:38.18 |
+09:30:38.1 |
HIP 57501 |
7.21 |
| 2026-05-31 00:00 |
11:47:37.78 |
+09:30:58.0 |
HIP 57501 |
7.23 |
| 2026-05-31 12:00 |
11:47:37.55 |
+09:31:16.6 |
HIP 57501 |
7.31 |
| 2026-06-01 00:00 |
11:47:37.48 |
+09:31:33.9 |
HIP 57501 |
7.42 |
| 2026-06-01 12:00 |
11:47:37.59 |
+09:31:50.1 |
HIP 57501 |
7.57 |
| 2026-06-02 00:00 |
11:47:37.86 |
+09:32:05.0 |
HIP 57501 |
7.75 |