| 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) |
| 2026-03-26 00:00 |
12:10:24.73 |
+05:39:01.6 |
HIP 59309 |
10.77 |
| 2026-03-26 12:00 |
12:10:07.92 |
+05:41:57.8 |
HIP 59309 |
6.55 |
| 2026-03-27 00:00 |
12:09:51.13 |
+05:44:53.6 |
HIP 59309 |
4.68 |
| 2026-03-27 12:00 |
12:09:34.35 |
+05:47:48.7 |
HIP 59309 |
7.28 |
| 2026-03-28 00:00 |
12:09:17.58 |
+05:50:43.3 |
HIP 59309 |
11.65 |
| 2026-03-28 12:00 |
12:09:00.84 |
+05:53:37.3 |
HIP 59309 |
16.43 |
| 2026-03-29 00:00 |
12:08:44.11 |
+05:56:30.7 |
HIP 59170 |
11.78 |
| 2026-03-29 12:00 |
12:08:27.41 |
+05:59:23.5 |
HIP 59170 |
6.77 |
| 2026-03-30 00:00 |
12:08:10.74 |
+06:02:15.6 |
HIP 59170 |
2.02 |
| 2026-03-30 12:00 |
12:07:54.10 |
+06:05:07.1 |
HIP 59170 |
3.62 |
| 2026-03-31 00:00 |
12:07:37.48 |
+06:07:57.8 |
HIP 59170 |
8.51 |
| 2026-03-31 12:00 |
12:07:20.90 |
+06:10:47.9 |
HIP 59170 |
13.48 |
| 2026-04-01 00:00 |
12:07:04.36 |
+06:13:37.3 |
HIP 59170 |
18.45 |
| 2026-04-01 12:00 |
12:06:47.86 |
+06:16:25.9 |
HIP 58958 |
21.33 |
| 2026-04-02 00:00 |
12:06:31.40 |
+06:19:13.8 |
HIP 58958 |
17.91 |
| 2026-04-02 12:00 |
12:06:14.98 |
+06:22:00.9 |
HIP 58958 |
15.34 |
| 2026-04-03 00:00 |
12:05:58.61 |
+06:24:47.2 |
HIP 58958 |
14.10 |
| 2026-04-03 12:00 |
12:05:42.28 |
+06:27:32.7 |
HIP 58958 |
14.51 |
| 2026-04-04 00:00 |
12:05:26.01 |
+06:30:17.4 |
HIP 58958 |
16.44 |
| 2026-04-04 12:00 |
12:05:09.79 |
+06:33:01.3 |
HIP 58958 |
19.41 |
| 2026-04-05 00:00 |
12:04:53.62 |
+06:35:44.3 |
HIP 58958 |
23.02 |
| 2026-04-05 12:00 |
12:04:37.52 |
+06:38:26.5 |
HIP 58958 |
27.00 |
| 2026-04-06 00:00 |
12:04:21.47 |
+06:41:07.7 |
HIP 58958 |
31.20 |
| 2026-04-06 12:00 |
12:04:05.49 |
+06:43:48.1 |
HIP 58958 |
35.54 |
| 2026-04-07 00:00 |
12:03:49.57 |
+06:46:27.5 |
HIP 58864 |
38.17 |
| 2026-04-07 12:00 |
12:03:33.71 |
+06:49:06.1 |
HIP 58638 |
36.47 |
| 2026-04-08 00:00 |
12:03:17.93 |
+06:51:43.6 |
HIP 58638 |
34.72 |
| 2026-04-08 12:00 |
12:03:02.22 |
+06:54:20.2 |
HIP 58638 |
33.55 |
| 2026-04-09 00:00 |
12:02:46.58 |
+06:56:55.8 |
HIP 58638 |
33.01 |
| 2026-04-09 12:00 |
12:02:31.02 |
+06:59:30.5 |
HIP 58638 |
33.12 |
| 2026-04-10 00:00 |
12:02:15.54 |
+07:02:04.1 |
HIP 58590 |
32.58 |
| 2026-04-10 12:00 |
12:02:00.14 |
+07:04:36.7 |
HIP 58590 |
32.45 |
| 2026-04-11 00:00 |
12:01:44.82 |
+07:07:08.3 |
HIP 58590 |
32.95 |
| 2026-04-11 12:00 |
12:01:29.59 |
+07:09:38.8 |
HIP 58590 |
34.06 |
| 2026-04-12 00:00 |
12:01:14.44 |
+07:12:08.2 |
HIP 58473 |
32.26 |
| 2026-04-12 12:00 |
12:00:59.39 |
+07:14:36.6 |
HIP 58473 |
30.90 |
| 2026-04-13 00:00 |
12:00:44.42 |
+07:17:03.8 |
HIP 58473 |
30.16 |
| 2026-04-13 12:00 |
12:00:29.55 |
+07:19:30.0 |
HIP 58473 |
30.06 |
| 2026-04-14 00:00 |
12:00:14.78 |
+07:21:55.0 |
HIP 58473 |
30.60 |
| 2026-04-14 12:00 |
12:00:00.10 |
+07:24:18.9 |
HIP 58372 |
28.72 |
| 2026-04-15 00:00 |
11:59:45.53 |
+07:26:41.7 |
HIP 58372 |
24.59 |
| 2026-04-15 12:00 |
11:59:31.05 |
+07:29:03.3 |
HIP 58372 |
20.58 |
| 2026-04-16 00:00 |
11:59:16.69 |
+07:31:23.7 |
HIP 58372 |
16.74 |