| Parameter |
Value |
| Designation |
C/1940 R2 (Cunningham) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1941-01-16T05:36:57.600000Z |
| Orbit solution date (soln_date, UTC) |
- |
| Obs used |
189 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1941-01-06.0000000 |
| e |
1.00048500 |
| q (au) |
0.367751 |
| a (au) |
-758.249484 |
| i (deg) |
49.894200 |
| Ω (om, deg) |
296.590500 |
| ω (w, deg) |
199.569000 |
| M (ma, deg) |
-0.000483 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.846 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.846 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
1.000 |
| 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) |
| 2026-06-01 00:00 |
20:21:16.60 |
-09:29:32.5 |
HIP 100524 |
27.46 |
| 2026-06-01 12:00 |
20:21:15.98 |
-09:29:32.4 |
HIP 100524 |
27.61 |
| 2026-06-02 00:00 |
20:21:15.35 |
-09:29:32.2 |
HIP 100524 |
27.76 |
| 2026-06-02 12:00 |
20:21:14.71 |
-09:29:32.2 |
HIP 100524 |
27.90 |
| 2026-06-03 00:00 |
20:21:14.06 |
-09:29:32.1 |
HIP 100524 |
28.05 |
| 2026-06-03 12:00 |
20:21:13.41 |
-09:29:32.1 |
HIP 100524 |
28.20 |
| 2026-06-04 00:00 |
20:21:12.75 |
-09:29:32.2 |
HIP 100524 |
28.36 |
| 2026-06-04 12:00 |
20:21:12.08 |
-09:29:32.3 |
HIP 100524 |
28.51 |
| 2026-06-05 00:00 |
20:21:11.41 |
-09:29:32.4 |
HIP 100524 |
28.67 |
| 2026-06-05 12:00 |
20:21:10.73 |
-09:29:32.5 |
HIP 100524 |
28.82 |
| 2026-06-06 00:00 |
20:21:10.04 |
-09:29:32.7 |
HIP 100524 |
28.98 |
| 2026-06-06 12:00 |
20:21:09.34 |
-09:29:32.9 |
HIP 100524 |
29.14 |
| 2026-06-07 00:00 |
20:21:08.64 |
-09:29:33.2 |
HIP 100524 |
29.30 |
| 2026-06-07 12:00 |
20:21:07.94 |
-09:29:33.5 |
HIP 100524 |
29.47 |
| 2026-06-08 00:00 |
20:21:07.22 |
-09:29:33.9 |
HIP 100524 |
29.63 |
| 2026-06-08 12:00 |
20:21:06.50 |
-09:29:34.3 |
HIP 100524 |
29.80 |
| 2026-06-09 00:00 |
20:21:05.78 |
-09:29:34.7 |
HIP 100524 |
29.96 |
| 2026-06-09 12:00 |
20:21:05.04 |
-09:29:35.1 |
HIP 100524 |
30.13 |
| 2026-06-10 00:00 |
20:21:04.30 |
-09:29:35.6 |
HIP 100524 |
30.30 |
| 2026-06-10 12:00 |
20:21:03.56 |
-09:29:36.2 |
HIP 100524 |
30.47 |
| 2026-06-11 00:00 |
20:21:02.81 |
-09:29:36.7 |
HIP 100524 |
30.65 |
| 2026-06-11 12:00 |
20:21:02.05 |
-09:29:37.4 |
HIP 100524 |
30.82 |
| 2026-06-12 00:00 |
20:21:01.28 |
-09:29:38.0 |
HIP 100524 |
31.00 |
| 2026-06-12 12:00 |
20:21:00.51 |
-09:29:38.7 |
HIP 100524 |
31.17 |
| 2026-06-13 00:00 |
20:20:59.74 |
-09:29:39.4 |
HIP 100524 |
31.35 |
| 2026-06-13 12:00 |
20:20:58.95 |
-09:29:40.2 |
HIP 100524 |
31.53 |
| 2026-06-14 00:00 |
20:20:58.17 |
-09:29:41.0 |
HIP 100524 |
31.71 |
| 2026-06-14 12:00 |
20:20:57.37 |
-09:29:41.8 |
HIP 100524 |
31.89 |
| 2026-06-15 00:00 |
20:20:56.57 |
-09:29:42.7 |
HIP 100524 |
32.08 |
| 2026-06-15 12:00 |
20:20:55.77 |
-09:29:43.6 |
HIP 100524 |
32.26 |
| 2026-06-16 00:00 |
20:20:54.96 |
-09:29:44.6 |
HIP 100524 |
32.45 |
| 2026-06-16 12:00 |
20:20:54.14 |
-09:29:45.6 |
HIP 100524 |
32.64 |
| 2026-06-17 00:00 |
20:20:53.32 |
-09:29:46.6 |
HIP 100524 |
32.83 |
| 2026-06-17 12:00 |
20:20:52.49 |
-09:29:47.7 |
HIP 100524 |
33.02 |
| 2026-06-18 00:00 |
20:20:51.65 |
-09:29:48.8 |
HIP 100524 |
33.21 |
| 2026-06-18 12:00 |
20:20:50.82 |
-09:29:49.9 |
HIP 100524 |
33.40 |
| 2026-06-19 00:00 |
20:20:49.97 |
-09:29:51.1 |
HIP 100524 |
33.60 |
| 2026-06-19 12:00 |
20:20:49.12 |
-09:29:52.3 |
HIP 100524 |
33.79 |
| 2026-06-20 00:00 |
20:20:48.27 |
-09:29:53.5 |
HIP 100524 |
33.99 |
| 2026-06-20 12:00 |
20:20:47.41 |
-09:29:54.8 |
HIP 100524 |
34.18 |
| 2026-06-21 00:00 |
20:20:46.55 |
-09:29:56.1 |
HIP 100524 |
34.38 |
| 2026-06-21 12:00 |
20:20:45.68 |
-09:29:57.5 |
HIP 100524 |
34.58 |
| 2026-06-22 00:00 |
20:20:44.80 |
-09:29:58.9 |
HIP 100524 |
34.79 |