C/1948 N1 (Wirtanen)
| Parameter |
Value |
| Designation |
C/1948 N1 (Wirtanen) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1949-05-01T03:57:14.875200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:09Z |
| Obs used |
20 |
| NEO |
- |
| M1 |
11.300 |
| K1 |
4.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1950-03-16.0000000 |
| e |
0.99945965 |
| q (au) |
2.517468 |
| a (au) |
4658.939225 |
| i (deg) |
130.267603 |
| Ω (om, deg) |
120.604872 |
| ω (w, deg) |
229.968351 |
| M (ma, deg) |
0.000988 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.043 + 4.134\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.043 |
| n |
4.134 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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) |
| 2026-02-03 00:00 |
06:45:39.31 |
+46:57:54.4 |
HIP 32373 |
6.58 |
| 2026-02-03 12:00 |
06:45:37.79 |
+46:57:51.7 |
HIP 32373 |
6.53 |
| 2026-02-04 00:00 |
06:45:36.27 |
+46:57:49.0 |
HIP 32373 |
6.49 |
| 2026-02-04 12:00 |
06:45:34.77 |
+46:57:46.2 |
HIP 32373 |
6.47 |
| 2026-02-05 00:00 |
06:45:33.27 |
+46:57:43.4 |
HIP 32373 |
6.45 |
| 2026-02-05 12:00 |
06:45:31.78 |
+46:57:40.5 |
HIP 32361 |
6.31 |
| 2026-02-06 00:00 |
06:45:30.30 |
+46:57:37.5 |
HIP 32361 |
6.17 |
| 2026-02-06 12:00 |
06:45:28.83 |
+46:57:34.5 |
HIP 32361 |
6.03 |
| 2026-02-07 00:00 |
06:45:27.37 |
+46:57:31.4 |
HIP 32361 |
5.91 |
| 2026-02-07 12:00 |
06:45:25.92 |
+46:57:28.2 |
HIP 32361 |
5.79 |
| 2026-02-08 00:00 |
06:45:24.47 |
+46:57:25.0 |
HIP 32361 |
5.68 |
| 2026-02-08 12:00 |
06:45:23.04 |
+46:57:21.8 |
HIP 32361 |
5.57 |
| 2026-02-09 00:00 |
06:45:21.62 |
+46:57:18.5 |
HIP 32361 |
5.48 |
| 2026-02-09 12:00 |
06:45:20.21 |
+46:57:15.1 |
HIP 32361 |
5.40 |
| 2026-02-10 00:00 |
06:45:18.81 |
+46:57:11.6 |
HIP 32361 |
5.32 |
| 2026-02-10 12:00 |
06:45:17.42 |
+46:57:08.2 |
HIP 32361 |
5.26 |
| 2026-02-11 00:00 |
06:45:16.04 |
+46:57:04.6 |
HIP 32361 |
5.20 |
| 2026-02-11 12:00 |
06:45:14.67 |
+46:57:01.0 |
HIP 32361 |
5.16 |
| 2026-02-12 00:00 |
06:45:13.31 |
+46:56:57.3 |
HIP 32361 |
5.12 |
| 2026-02-12 12:00 |
06:45:11.96 |
+46:56:53.6 |
HIP 32361 |
5.09 |
| 2026-02-13 00:00 |
06:45:10.62 |
+46:56:49.8 |
HIP 32361 |
5.08 |
| 2026-02-13 12:00 |
06:45:09.29 |
+46:56:46.0 |
HIP 32361 |
5.07 |
| 2026-02-14 00:00 |
06:45:07.98 |
+46:56:42.1 |
HIP 32361 |
5.07 |
| 2026-02-14 12:00 |
06:45:06.67 |
+46:56:38.2 |
HIP 32361 |
5.08 |
| 2026-02-15 00:00 |
06:45:05.38 |
+46:56:34.2 |
HIP 32361 |
5.10 |
| 2026-02-15 12:00 |
06:45:04.10 |
+46:56:30.1 |
HIP 32361 |
5.13 |
| 2026-02-16 00:00 |
06:45:02.82 |
+46:56:26.0 |
HIP 32361 |
5.17 |
| 2026-02-16 12:00 |
06:45:01.57 |
+46:56:21.9 |
HIP 32361 |
5.22 |
| 2026-02-17 00:00 |
06:45:00.32 |
+46:56:17.7 |
HIP 32361 |
5.27 |
| 2026-02-17 12:00 |
06:44:59.08 |
+46:56:13.4 |
HIP 32361 |
5.33 |
| 2026-02-18 00:00 |
06:44:57.86 |
+46:56:09.1 |
HIP 32361 |
5.40 |
| 2026-02-18 12:00 |
06:44:56.65 |
+46:56:04.7 |
HIP 32361 |
5.47 |
| 2026-02-19 00:00 |
06:44:55.45 |
+46:56:00.3 |
HIP 32361 |
5.55 |
| 2026-02-19 12:00 |
06:44:54.26 |
+46:55:55.9 |
HIP 32361 |
5.63 |
| 2026-02-20 00:00 |
06:44:53.08 |
+46:55:51.3 |
HIP 32361 |
5.72 |
| 2026-02-20 12:00 |
06:44:51.92 |
+46:55:46.8 |
HIP 32361 |
5.82 |
| 2026-02-21 00:00 |
06:44:50.77 |
+46:55:42.2 |
HIP 32361 |
5.91 |
| 2026-02-21 12:00 |
06:44:49.63 |
+46:55:37.5 |
HIP 32361 |
6.01 |
| 2026-02-22 00:00 |
06:44:48.51 |
+46:55:32.8 |
HIP 32361 |
6.12 |
| 2026-02-22 12:00 |
06:44:47.39 |
+46:55:28.0 |
HIP 32361 |
6.22 |
| 2026-02-23 00:00 |
06:44:46.29 |
+46:55:23.2 |
HIP 32361 |
6.33 |
| 2026-02-23 12:00 |
06:44:45.20 |
+46:55:18.4 |
HIP 32361 |
6.45 |
| 2026-02-24 00:00 |
06:44:44.13 |
+46:55:13.5 |
HIP 32361 |
6.56 |