| Parameter |
Value |
| Designation |
C/1937 D1 (Wilk) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1937-02-21T12:38:22.404480Z |
| Orbit solution date (soln_date, UTC) |
2024-02-20T20:16:49Z |
| Obs used |
17 |
| NEO |
Yes |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1937-03-17.0000000 |
| e |
0.98064326 |
| q (au) |
0.618890 |
| a (au) |
31.972825 |
| i (deg) |
26.014023 |
| Ω (om, deg) |
58.270037 |
| ω (w, deg) |
31.457951 |
| M (ma, deg) |
0.127970 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.016 + 4.637\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.016 |
| n |
4.637 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
0.940 |
| δ90 |
1.000 |
| 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) |
| 2026-07-29 00:00 |
17:42:37.71 |
-36:44:49.5 |
HIP 86698 |
12.20 |
| 2026-07-29 12:00 |
17:42:35.97 |
-36:44:45.0 |
HIP 86698 |
12.36 |
| 2026-07-30 00:00 |
17:42:34.24 |
-36:44:40.3 |
HIP 86698 |
12.52 |
| 2026-07-30 12:00 |
17:42:32.53 |
-36:44:35.6 |
HIP 86698 |
12.69 |
| 2026-07-31 00:00 |
17:42:30.82 |
-36:44:30.9 |
HIP 86698 |
12.87 |
| 2026-07-31 12:00 |
17:42:29.14 |
-36:44:26.2 |
HIP 86698 |
13.06 |
| 2026-08-01 00:00 |
17:42:27.46 |
-36:44:21.4 |
HIP 86698 |
13.25 |
| 2026-08-01 12:00 |
17:42:25.80 |
-36:44:16.6 |
HIP 86698 |
13.44 |
| 2026-08-02 00:00 |
17:42:24.15 |
-36:44:11.7 |
HIP 86698 |
13.64 |
| 2026-08-02 12:00 |
17:42:22.52 |
-36:44:06.9 |
HIP 86698 |
13.85 |
| 2026-08-03 00:00 |
17:42:20.90 |
-36:44:01.9 |
HIP 86698 |
14.06 |
| 2026-08-03 12:00 |
17:42:19.29 |
-36:43:57.0 |
HIP 86698 |
14.28 |
| 2026-08-04 00:00 |
17:42:17.70 |
-36:43:52.0 |
HIP 86698 |
14.50 |
| 2026-08-04 12:00 |
17:42:16.12 |
-36:43:47.0 |
HIP 86698 |
14.72 |
| 2026-08-05 00:00 |
17:42:14.56 |
-36:43:41.9 |
HIP 86698 |
14.94 |
| 2026-08-05 12:00 |
17:42:13.01 |
-36:43:36.8 |
HIP 86698 |
15.17 |
| 2026-08-06 00:00 |
17:42:11.48 |
-36:43:31.7 |
HIP 86698 |
15.40 |
| 2026-08-06 12:00 |
17:42:09.96 |
-36:43:26.5 |
HIP 86698 |
15.63 |
| 2026-08-07 00:00 |
17:42:08.46 |
-36:43:21.3 |
HIP 86698 |
15.86 |
| 2026-08-07 12:00 |
17:42:06.97 |
-36:43:16.1 |
HIP 86698 |
16.10 |
| 2026-08-08 00:00 |
17:42:05.49 |
-36:43:10.9 |
HIP 86698 |
16.34 |
| 2026-08-08 12:00 |
17:42:04.03 |
-36:43:05.6 |
HIP 86698 |
16.57 |
| 2026-08-09 00:00 |
17:42:02.59 |
-36:43:00.3 |
HIP 86698 |
16.81 |
| 2026-08-09 12:00 |
17:42:01.16 |
-36:42:54.9 |
HIP 86698 |
17.05 |
| 2026-08-10 00:00 |
17:41:59.75 |
-36:42:49.5 |
HIP 86698 |
17.29 |
| 2026-08-10 12:00 |
17:41:58.35 |
-36:42:44.1 |
HIP 86698 |
17.53 |
| 2026-08-11 00:00 |
17:41:56.97 |
-36:42:38.7 |
HIP 86698 |
17.77 |
| 2026-08-11 12:00 |
17:41:55.61 |
-36:42:33.3 |
HIP 86698 |
18.01 |
| 2026-08-12 00:00 |
17:41:54.26 |
-36:42:27.8 |
HIP 86698 |
18.25 |
| 2026-08-12 12:00 |
17:41:52.93 |
-36:42:22.3 |
HIP 86698 |
18.48 |
| 2026-08-13 00:00 |
17:41:51.61 |
-36:42:16.7 |
HIP 86698 |
18.72 |
| 2026-08-13 12:00 |
17:41:50.31 |
-36:42:11.2 |
HIP 86698 |
18.96 |
| 2026-08-14 00:00 |
17:41:49.03 |
-36:42:05.6 |
HIP 86698 |
19.20 |
| 2026-08-14 12:00 |
17:41:47.76 |
-36:42:00.0 |
HIP 86698 |
19.43 |
| 2026-08-15 00:00 |
17:41:46.51 |
-36:41:54.3 |
HIP 86698 |
19.67 |
| 2026-08-15 12:00 |
17:41:45.28 |
-36:41:48.6 |
HIP 86698 |
19.90 |
| 2026-08-16 00:00 |
17:41:44.06 |
-36:41:43.0 |
HIP 86698 |
20.13 |
| 2026-08-16 12:00 |
17:41:42.86 |
-36:41:37.2 |
HIP 86698 |
20.37 |
| 2026-08-17 00:00 |
17:41:41.68 |
-36:41:31.5 |
HIP 86698 |
20.60 |
| 2026-08-17 12:00 |
17:41:40.52 |
-36:41:25.8 |
HIP 86698 |
20.82 |
| 2026-08-18 00:00 |
17:41:39.37 |
-36:41:20.0 |
HIP 86698 |
21.05 |
| 2026-08-18 12:00 |
17:41:38.24 |
-36:41:14.2 |
HIP 86698 |
21.28 |
| 2026-08-19 00:00 |
17:41:37.13 |
-36:41:08.4 |
HIP 86698 |
21.50 |