| Parameter |
Value |
| Designation |
C/1947 O1 (Wirtanen) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1947-07-16T20:09:37.615680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:07Z |
| Obs used |
3 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1948-03-29.0000000 |
| e |
1.01675158 |
| q (au) |
2.807881 |
| a (au) |
-167.618847 |
| i (deg) |
97.324802 |
| Ω (om, deg) |
311.764379 |
| ω (w, deg) |
8.848565 |
| M (ma, deg) |
0.116341 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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) |
| 2026-06-01 00:00 |
09:17:18.68 |
+28:40:32.5 |
HIP 45617 |
10.24 |
| 2026-06-01 12:00 |
09:17:19.13 |
+28:40:27.0 |
HIP 45617 |
10.11 |
| 2026-06-02 00:00 |
09:17:19.59 |
+28:40:21.4 |
HIP 45617 |
9.97 |
| 2026-06-02 12:00 |
09:17:20.06 |
+28:40:15.8 |
HIP 45617 |
9.83 |
| 2026-06-03 00:00 |
09:17:20.54 |
+28:40:10.1 |
HIP 45617 |
9.69 |
| 2026-06-03 12:00 |
09:17:21.03 |
+28:40:04.5 |
HIP 45617 |
9.55 |
| 2026-06-04 00:00 |
09:17:21.53 |
+28:39:58.8 |
HIP 45617 |
9.40 |
| 2026-06-04 12:00 |
09:17:22.03 |
+28:39:53.1 |
HIP 45617 |
9.26 |
| 2026-06-05 00:00 |
09:17:22.55 |
+28:39:47.4 |
HIP 45617 |
9.11 |
| 2026-06-05 12:00 |
09:17:23.07 |
+28:39:41.6 |
HIP 45617 |
8.96 |
| 2026-06-06 00:00 |
09:17:23.60 |
+28:39:35.9 |
HIP 45617 |
8.81 |
| 2026-06-06 12:00 |
09:17:24.14 |
+28:39:30.1 |
HIP 45617 |
8.65 |
| 2026-06-07 00:00 |
09:17:24.69 |
+28:39:24.3 |
HIP 45617 |
8.50 |
| 2026-06-07 12:00 |
09:17:25.25 |
+28:39:18.5 |
HIP 45617 |
8.34 |
| 2026-06-08 00:00 |
09:17:25.81 |
+28:39:12.6 |
HIP 45617 |
8.19 |
| 2026-06-08 12:00 |
09:17:26.39 |
+28:39:06.8 |
HIP 45617 |
8.03 |
| 2026-06-09 00:00 |
09:17:26.97 |
+28:39:00.9 |
HIP 45617 |
7.87 |
| 2026-06-09 12:00 |
09:17:27.56 |
+28:38:55.0 |
HIP 45617 |
7.71 |
| 2026-06-10 00:00 |
09:17:28.16 |
+28:38:49.1 |
HIP 45617 |
7.54 |
| 2026-06-10 12:00 |
09:17:28.77 |
+28:38:43.1 |
HIP 45617 |
7.38 |
| 2026-06-11 00:00 |
09:17:29.39 |
+28:38:37.2 |
HIP 45617 |
7.21 |
| 2026-06-11 12:00 |
09:17:30.02 |
+28:38:31.2 |
HIP 45617 |
7.04 |
| 2026-06-12 00:00 |
09:17:30.65 |
+28:38:25.2 |
HIP 45617 |
6.87 |
| 2026-06-12 12:00 |
09:17:31.29 |
+28:38:19.2 |
HIP 45617 |
6.70 |
| 2026-06-13 00:00 |
09:17:31.94 |
+28:38:13.2 |
HIP 45617 |
6.53 |
| 2026-06-13 12:00 |
09:17:32.60 |
+28:38:07.1 |
HIP 45617 |
6.35 |
| 2026-06-14 00:00 |
09:17:33.27 |
+28:38:01.1 |
HIP 45617 |
6.18 |
| 2026-06-14 12:00 |
09:17:33.94 |
+28:37:55.0 |
HIP 45617 |
6.00 |
| 2026-06-15 00:00 |
09:17:34.62 |
+28:37:48.9 |
HIP 45617 |
5.82 |
| 2026-06-15 12:00 |
09:17:35.31 |
+28:37:42.8 |
HIP 45617 |
5.65 |
| 2026-06-16 00:00 |
09:17:36.01 |
+28:37:36.7 |
HIP 45617 |
5.47 |
| 2026-06-16 12:00 |
09:17:36.72 |
+28:37:30.6 |
HIP 45617 |
5.28 |
| 2026-06-17 00:00 |
09:17:37.43 |
+28:37:24.5 |
HIP 45617 |
5.10 |
| 2026-06-17 12:00 |
09:17:38.15 |
+28:37:18.3 |
HIP 45617 |
4.92 |
| 2026-06-18 00:00 |
09:17:38.88 |
+28:37:12.2 |
HIP 45617 |
4.74 |
| 2026-06-18 12:00 |
09:17:39.62 |
+28:37:06.0 |
HIP 45617 |
4.55 |
| 2026-06-19 00:00 |
09:17:40.36 |
+28:36:59.8 |
HIP 45617 |
4.37 |
| 2026-06-19 12:00 |
09:17:41.12 |
+28:36:53.7 |
HIP 45617 |
4.18 |
| 2026-06-20 00:00 |
09:17:41.87 |
+28:36:47.5 |
HIP 45617 |
3.99 |
| 2026-06-20 12:00 |
09:17:42.64 |
+28:36:41.3 |
HIP 45617 |
3.81 |
| 2026-06-21 00:00 |
09:17:43.41 |
+28:36:35.0 |
HIP 45617 |
3.62 |
| 2026-06-21 12:00 |
09:17:44.20 |
+28:36:28.8 |
HIP 45617 |
3.44 |
| 2026-06-22 00:00 |
09:17:44.98 |
+28:36:22.6 |
HIP 45617 |
3.25 |