| 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) |
| 2026-09-20 00:00 |
06:50:33.88 |
+46:41:05.4 |
HIP 32949 |
16.87 |
| 2026-09-20 12:00 |
06:50:34.26 |
+46:41:12.3 |
HIP 32949 |
16.89 |
| 2026-09-21 00:00 |
06:50:34.63 |
+46:41:19.3 |
HIP 32949 |
16.92 |
| 2026-09-21 12:00 |
06:50:34.98 |
+46:41:26.3 |
HIP 32949 |
16.96 |
| 2026-09-22 00:00 |
06:50:35.32 |
+46:41:33.3 |
HIP 32949 |
16.99 |
| 2026-09-22 12:00 |
06:50:35.65 |
+46:41:40.4 |
HIP 32949 |
17.03 |
| 2026-09-23 00:00 |
06:50:35.96 |
+46:41:47.5 |
HIP 32949 |
17.07 |
| 2026-09-23 12:00 |
06:50:36.26 |
+46:41:54.6 |
HIP 32949 |
17.12 |
| 2026-09-24 00:00 |
06:50:36.54 |
+46:42:01.7 |
HIP 32949 |
17.17 |
| 2026-09-24 12:00 |
06:50:36.81 |
+46:42:08.8 |
HIP 32949 |
17.22 |
| 2026-09-25 00:00 |
06:50:37.06 |
+46:42:16.0 |
HIP 32949 |
17.27 |
| 2026-09-25 12:00 |
06:50:37.30 |
+46:42:23.2 |
HIP 32949 |
17.33 |
| 2026-09-26 00:00 |
06:50:37.53 |
+46:42:30.4 |
HIP 32949 |
17.39 |
| 2026-09-26 12:00 |
06:50:37.74 |
+46:42:37.7 |
HIP 32949 |
17.45 |
| 2026-09-27 00:00 |
06:50:37.93 |
+46:42:45.0 |
HIP 32949 |
17.51 |
| 2026-09-27 12:00 |
06:50:38.12 |
+46:42:52.2 |
HIP 32949 |
17.58 |
| 2026-09-28 00:00 |
06:50:38.28 |
+46:42:59.6 |
HIP 32949 |
17.65 |
| 2026-09-28 12:00 |
06:50:38.44 |
+46:43:06.9 |
HIP 32949 |
17.72 |
| 2026-09-29 00:00 |
06:50:38.57 |
+46:43:14.2 |
HIP 32949 |
17.80 |
| 2026-09-29 12:00 |
06:50:38.70 |
+46:43:21.6 |
HIP 32949 |
17.88 |
| 2026-09-30 00:00 |
06:50:38.80 |
+46:43:29.0 |
HIP 32949 |
17.96 |
| 2026-09-30 12:00 |
06:50:38.90 |
+46:43:36.4 |
HIP 32949 |
18.04 |
| 2026-10-01 00:00 |
06:50:38.98 |
+46:43:43.8 |
HIP 32949 |
18.12 |
| 2026-10-01 12:00 |
06:50:39.04 |
+46:43:51.3 |
HIP 32949 |
18.21 |
| 2026-10-02 00:00 |
06:50:39.09 |
+46:43:58.7 |
HIP 32949 |
18.30 |
| 2026-10-02 12:00 |
06:50:39.12 |
+46:44:06.2 |
HIP 32949 |
18.39 |
| 2026-10-03 00:00 |
06:50:39.14 |
+46:44:13.7 |
HIP 32949 |
18.48 |
| 2026-10-03 12:00 |
06:50:39.15 |
+46:44:21.2 |
HIP 32949 |
18.58 |
| 2026-10-04 00:00 |
06:50:39.14 |
+46:44:28.8 |
HIP 32949 |
18.68 |
| 2026-10-04 12:00 |
06:50:39.11 |
+46:44:36.3 |
HIP 32949 |
18.78 |
| 2026-10-05 00:00 |
06:50:39.07 |
+46:44:43.9 |
HIP 32949 |
18.88 |
| 2026-10-05 12:00 |
06:50:39.02 |
+46:44:51.4 |
HIP 32949 |
18.98 |
| 2026-10-06 00:00 |
06:50:38.95 |
+46:44:59.0 |
HIP 32949 |
19.09 |
| 2026-10-06 12:00 |
06:50:38.86 |
+46:45:06.6 |
HIP 32949 |
19.20 |
| 2026-10-07 00:00 |
06:50:38.76 |
+46:45:14.2 |
HIP 32949 |
19.31 |
| 2026-10-07 12:00 |
06:50:38.65 |
+46:45:21.8 |
HIP 32949 |
19.42 |
| 2026-10-08 00:00 |
06:50:38.52 |
+46:45:29.5 |
HIP 32949 |
19.54 |
| 2026-10-08 12:00 |
06:50:38.37 |
+46:45:37.1 |
HIP 32949 |
19.65 |
| 2026-10-09 00:00 |
06:50:38.21 |
+46:45:44.8 |
HIP 32949 |
19.77 |
| 2026-10-09 12:00 |
06:50:38.04 |
+46:45:52.4 |
HIP 32949 |
19.89 |
| 2026-10-10 00:00 |
06:50:37.85 |
+46:46:00.1 |
HIP 32949 |
20.01 |
| 2026-10-10 12:00 |
06:50:37.64 |
+46:46:07.8 |
HIP 32949 |
20.13 |
| 2026-10-11 00:00 |
06:50:37.42 |
+46:46:15.5 |
HIP 32949 |
20.26 |