| Parameter |
Value |
| Designation |
213P/Van Ness |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2017-09-24T09:09:50.725440Z |
| Orbit solution date (soln_date, UTC) |
2025-04-11T15:15:55Z |
| Obs used |
367 |
| NEO |
- |
| M1 |
10.800 |
| K1 |
16.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-02-12.0000000 |
| e |
0.40755795 |
| q (au) |
1.983344 |
| a (au) |
3.347744 |
| i (deg) |
10.377842 |
| Ω (om, deg) |
311.315921 |
| ω (w, deg) |
5.559827 |
| M (ma, deg) |
22.626485 |
Magnitude
Scatter + Global Linear
$$
M_a = (18.185 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
18.185 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.598 |
| k |
0.800 |
| 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) |
| 2026-05-12 00:00 |
07:30:31.13 |
+23:19:22.4 |
HIP 36560 |
10.56 |
| 2026-05-12 12:00 |
07:30:52.26 |
+23:18:06.3 |
HIP 36560 |
5.62 |
| 2026-05-13 00:00 |
07:31:13.49 |
+23:16:49.9 |
HIP 36560 |
1.40 |
| 2026-05-13 12:00 |
07:31:34.85 |
+23:15:33.2 |
HIP 36560 |
4.84 |
| 2026-05-14 00:00 |
07:31:56.31 |
+23:14:16.2 |
HIP 36560 |
9.84 |
| 2026-05-14 12:00 |
07:32:17.88 |
+23:12:58.9 |
HIP 36560 |
14.93 |
| 2026-05-15 00:00 |
07:32:39.56 |
+23:11:41.2 |
HIP 36690 |
18.60 |
| 2026-05-15 12:00 |
07:33:01.35 |
+23:10:23.3 |
HIP 36690 |
17.31 |
| 2026-05-16 00:00 |
07:33:23.25 |
+23:09:05.0 |
HIP 36690 |
17.51 |
| 2026-05-16 12:00 |
07:33:45.25 |
+23:07:46.4 |
HIP 36864 |
17.24 |
| 2026-05-17 00:00 |
07:34:07.35 |
+23:06:27.5 |
HIP 36864 |
12.59 |
| 2026-05-17 12:00 |
07:34:29.56 |
+23:05:08.3 |
HIP 36864 |
8.65 |
| 2026-05-18 00:00 |
07:34:51.87 |
+23:03:48.8 |
HIP 36898 |
4.60 |
| 2026-05-18 12:00 |
07:35:14.28 |
+23:02:29.0 |
HIP 36898 |
0.73 |
| 2026-05-19 00:00 |
07:35:36.79 |
+23:01:08.8 |
HIP 36898 |
6.08 |
| 2026-05-19 12:00 |
07:35:59.40 |
+22:59:48.3 |
HIP 36898 |
11.45 |
| 2026-05-20 00:00 |
07:36:22.11 |
+22:58:27.5 |
HIP 36898 |
16.85 |
| 2026-05-20 12:00 |
07:36:44.91 |
+22:57:06.4 |
HIP 36898 |
22.26 |
| 2026-05-21 00:00 |
07:37:07.80 |
+22:55:44.9 |
HIP 36898 |
27.71 |
| 2026-05-21 12:00 |
07:37:30.79 |
+22:54:23.2 |
HIP 36898 |
33.17 |
| 2026-05-22 00:00 |
07:37:53.87 |
+22:53:01.1 |
HIP 37121 |
32.76 |
| 2026-05-22 12:00 |
07:38:17.04 |
+22:51:38.7 |
HIP 37121 |
32.37 |
| 2026-05-23 00:00 |
07:38:40.31 |
+22:50:16.0 |
HIP 37203 |
31.83 |
| 2026-05-23 12:00 |
07:39:03.66 |
+22:48:52.9 |
HIP 37428 |
29.14 |
| 2026-05-24 00:00 |
07:39:27.09 |
+22:47:29.5 |
HIP 37428 |
25.08 |
| 2026-05-24 12:00 |
07:39:50.62 |
+22:46:05.8 |
HIP 37428 |
21.68 |
| 2026-05-25 00:00 |
07:40:14.23 |
+22:44:41.8 |
HIP 37428 |
19.33 |
| 2026-05-25 12:00 |
07:40:37.92 |
+22:43:17.5 |
HIP 37428 |
18.44 |
| 2026-05-26 00:00 |
07:41:01.70 |
+22:41:52.8 |
HIP 37428 |
19.25 |
| 2026-05-26 12:00 |
07:41:25.56 |
+22:40:27.8 |
HIP 37522 |
17.78 |
| 2026-05-27 00:00 |
07:41:49.50 |
+22:39:02.5 |
HIP 37522 |
17.07 |
| 2026-05-27 12:00 |
07:42:13.52 |
+22:37:36.9 |
HIP 37522 |
18.22 |
| 2026-05-28 00:00 |
07:42:37.62 |
+22:36:10.9 |
HIP 37636 |
15.98 |
| 2026-05-28 12:00 |
07:43:01.80 |
+22:34:44.6 |
HIP 37636 |
11.76 |
| 2026-05-29 00:00 |
07:43:26.06 |
+22:33:18.0 |
HIP 37636 |
9.38 |
| 2026-05-29 12:00 |
07:43:50.39 |
+22:31:51.1 |
HIP 37636 |
10.23 |
| 2026-05-30 00:00 |
07:44:14.80 |
+22:30:23.8 |
HIP 37636 |
13.75 |
| 2026-05-30 12:00 |
07:44:39.28 |
+22:28:56.2 |
HIP 37636 |
18.49 |
| 2026-05-31 00:00 |
07:45:03.84 |
+22:27:28.2 |
HIP 37636 |
23.75 |
| 2026-05-31 12:00 |
07:45:28.47 |
+22:26:00.0 |
HIP 37636 |
29.25 |
| 2026-06-01 00:00 |
07:45:53.17 |
+22:24:31.4 |
HIP 37986 |
25.03 |
| 2026-06-01 12:00 |
07:46:17.94 |
+22:23:02.4 |
HIP 37986 |
20.25 |
| 2026-06-02 00:00 |
07:46:42.78 |
+22:21:33.2 |
HIP 37986 |
16.24 |