C/1948 T1 (Wirtanen)
| Parameter |
Value |
| Designation |
C/1948 T1 (Wirtanen) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1947-09-03T21:00:21.755520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:09Z |
| Obs used |
19 |
| NEO |
- |
| M1 |
6.000 |
| K1 |
8.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1949-11-26.0000000 |
| e |
1.00069715 |
| q (au) |
3.268165 |
| a (au) |
-4687.881007 |
| i (deg) |
155.078426 |
| Ω (om, deg) |
122.125436 |
| ω (w, deg) |
73.549407 |
| M (ma, deg) |
0.002500 |
Magnitude
Scatter + Global Linear
$$
M_a = (-0.036 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-0.036 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| 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 |
16:31:27.58 |
-41:36:38.2 |
HIP 80932 |
2.99 |
| 2026-02-03 12:00 |
16:31:28.23 |
-41:36:44.8 |
HIP 80932 |
2.84 |
| 2026-02-04 00:00 |
16:31:28.87 |
-41:36:51.4 |
HIP 80932 |
2.70 |
| 2026-02-04 12:00 |
16:31:29.49 |
-41:36:58.1 |
HIP 80932 |
2.55 |
| 2026-02-05 00:00 |
16:31:30.11 |
-41:37:04.7 |
HIP 80932 |
2.41 |
| 2026-02-05 12:00 |
16:31:30.71 |
-41:37:11.3 |
HIP 80932 |
2.27 |
| 2026-02-06 00:00 |
16:31:31.30 |
-41:37:17.9 |
HIP 80932 |
2.14 |
| 2026-02-06 12:00 |
16:31:31.88 |
-41:37:24.6 |
HIP 80932 |
2.01 |
| 2026-02-07 00:00 |
16:31:32.44 |
-41:37:31.2 |
HIP 80932 |
1.88 |
| 2026-02-07 12:00 |
16:31:32.99 |
-41:37:37.8 |
HIP 80932 |
1.76 |
| 2026-02-08 00:00 |
16:31:33.53 |
-41:37:44.5 |
HIP 80932 |
1.64 |
| 2026-02-08 12:00 |
16:31:34.06 |
-41:37:51.1 |
HIP 80932 |
1.53 |
| 2026-02-09 00:00 |
16:31:34.57 |
-41:37:57.7 |
HIP 80932 |
1.43 |
| 2026-02-09 12:00 |
16:31:35.07 |
-41:38:04.4 |
HIP 80932 |
1.33 |
| 2026-02-10 00:00 |
16:31:35.56 |
-41:38:11.0 |
HIP 80932 |
1.24 |
| 2026-02-10 12:00 |
16:31:36.03 |
-41:38:17.6 |
HIP 80932 |
1.16 |
| 2026-02-11 00:00 |
16:31:36.49 |
-41:38:24.2 |
HIP 80932 |
1.09 |
| 2026-02-11 12:00 |
16:31:36.94 |
-41:38:30.8 |
HIP 80932 |
1.04 |
| 2026-02-12 00:00 |
16:31:37.37 |
-41:38:37.5 |
HIP 80932 |
1.00 |
| 2026-02-12 12:00 |
16:31:37.80 |
-41:38:44.1 |
HIP 80932 |
0.98 |
| 2026-02-13 00:00 |
16:31:38.20 |
-41:38:50.7 |
HIP 80932 |
0.97 |
| 2026-02-13 12:00 |
16:31:38.60 |
-41:38:57.3 |
HIP 80932 |
0.98 |
| 2026-02-14 00:00 |
16:31:38.98 |
-41:39:03.8 |
HIP 80932 |
1.00 |
| 2026-02-14 12:00 |
16:31:39.35 |
-41:39:10.4 |
HIP 80932 |
1.04 |
| 2026-02-15 00:00 |
16:31:39.71 |
-41:39:17.0 |
HIP 80932 |
1.09 |
| 2026-02-15 12:00 |
16:31:40.05 |
-41:39:23.6 |
HIP 80932 |
1.15 |
| 2026-02-16 00:00 |
16:31:40.38 |
-41:39:30.1 |
HIP 80932 |
1.22 |
| 2026-02-16 12:00 |
16:31:40.69 |
-41:39:36.7 |
HIP 80932 |
1.29 |
| 2026-02-17 00:00 |
16:31:40.99 |
-41:39:43.2 |
HIP 80932 |
1.37 |
| 2026-02-17 12:00 |
16:31:41.28 |
-41:39:49.7 |
HIP 80932 |
1.45 |
| 2026-02-18 00:00 |
16:31:41.56 |
-41:39:56.2 |
HIP 80932 |
1.53 |
| 2026-02-18 12:00 |
16:31:41.82 |
-41:40:02.7 |
HIP 80932 |
1.62 |
| 2026-02-19 00:00 |
16:31:42.06 |
-41:40:09.2 |
HIP 80932 |
1.71 |
| 2026-02-19 12:00 |
16:31:42.30 |
-41:40:15.7 |
HIP 80932 |
1.80 |
| 2026-02-20 00:00 |
16:31:42.52 |
-41:40:22.2 |
HIP 80932 |
1.89 |
| 2026-02-20 12:00 |
16:31:42.72 |
-41:40:28.6 |
HIP 80932 |
1.98 |
| 2026-02-21 00:00 |
16:31:42.91 |
-41:40:35.1 |
HIP 80932 |
2.07 |
| 2026-02-21 12:00 |
16:31:43.09 |
-41:40:41.5 |
HIP 80932 |
2.16 |
| 2026-02-22 00:00 |
16:31:43.26 |
-41:40:47.9 |
HIP 80932 |
2.25 |
| 2026-02-22 12:00 |
16:31:43.41 |
-41:40:54.3 |
HIP 80932 |
2.34 |
| 2026-02-23 00:00 |
16:31:43.55 |
-41:41:00.7 |
HIP 80932 |
2.43 |
| 2026-02-23 12:00 |
16:31:43.67 |
-41:41:07.1 |
HIP 80932 |
2.52 |
| 2026-02-24 00:00 |
16:31:43.78 |
-41:41:13.4 |
HIP 80932 |
2.61 |