C/1977 R1 (Kohler)
| Parameter |
Value |
| Designation |
C/1977 R1 (Kohler) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1977-11-10T13:40:46.989120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:27Z |
| Obs used |
421 |
| NEO |
- |
| M1 |
7.300 |
| K1 |
13.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1977-11-01.0000000 |
| e |
0.99954935 |
| q (au) |
0.990576 |
| a (au) |
2198.096723 |
| i (deg) |
48.711865 |
| Ω (om, deg) |
182.522684 |
| ω (w, deg) |
163.486616 |
| M (ma, deg) |
359.999908 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.933 + 5.854\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.933 |
| n |
5.854 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.800 |
| 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) |
| 2026-02-03 00:00 |
10:20:36.44 |
-13:23:56.8 |
HIP 50787 |
22.95 |
| 2026-02-03 12:00 |
10:20:34.96 |
-13:23:52.2 |
HIP 50787 |
23.32 |
| 2026-02-04 00:00 |
10:20:33.48 |
-13:23:47.5 |
HIP 50787 |
23.68 |
| 2026-02-04 12:00 |
10:20:32.00 |
-13:23:42.7 |
HIP 50787 |
24.04 |
| 2026-02-05 00:00 |
10:20:30.51 |
-13:23:37.8 |
HIP 50787 |
24.41 |
| 2026-02-05 12:00 |
10:20:29.02 |
-13:23:32.8 |
HIP 50787 |
24.77 |
| 2026-02-06 00:00 |
10:20:27.52 |
-13:23:27.6 |
HIP 50787 |
25.14 |
| 2026-02-06 12:00 |
10:20:26.02 |
-13:23:22.4 |
HIP 50787 |
25.51 |
| 2026-02-07 00:00 |
10:20:24.52 |
-13:23:17.1 |
HIP 50787 |
25.88 |
| 2026-02-07 12:00 |
10:20:23.01 |
-13:23:11.6 |
HIP 50787 |
26.25 |
| 2026-02-08 00:00 |
10:20:21.50 |
-13:23:06.1 |
HIP 50787 |
26.62 |
| 2026-02-08 12:00 |
10:20:19.98 |
-13:23:00.4 |
HIP 50787 |
26.99 |
| 2026-02-09 00:00 |
10:20:18.46 |
-13:22:54.7 |
HIP 50787 |
27.37 |
| 2026-02-09 12:00 |
10:20:16.94 |
-13:22:48.8 |
HIP 50787 |
27.74 |
| 2026-02-10 00:00 |
10:20:15.42 |
-13:22:42.9 |
HIP 50476 |
27.53 |
| 2026-02-10 12:00 |
10:20:13.89 |
-13:22:36.8 |
HIP 50476 |
27.14 |
| 2026-02-11 00:00 |
10:20:12.36 |
-13:22:30.6 |
HIP 50476 |
26.76 |
| 2026-02-11 12:00 |
10:20:10.82 |
-13:22:24.4 |
HIP 50476 |
26.37 |
| 2026-02-12 00:00 |
10:20:09.29 |
-13:22:18.0 |
HIP 50476 |
25.99 |
| 2026-02-12 12:00 |
10:20:07.75 |
-13:22:11.5 |
HIP 50476 |
25.60 |
| 2026-02-13 00:00 |
10:20:06.21 |
-13:22:05.0 |
HIP 50476 |
25.21 |
| 2026-02-13 12:00 |
10:20:04.66 |
-13:21:58.3 |
HIP 50476 |
24.83 |
| 2026-02-14 00:00 |
10:20:03.12 |
-13:21:51.5 |
HIP 50476 |
24.44 |
| 2026-02-14 12:00 |
10:20:01.57 |
-13:21:44.7 |
HIP 50476 |
24.05 |
| 2026-02-15 00:00 |
10:20:00.02 |
-13:21:37.7 |
HIP 50476 |
23.66 |
| 2026-02-15 12:00 |
10:19:58.47 |
-13:21:30.7 |
HIP 50476 |
23.27 |
| 2026-02-16 00:00 |
10:19:56.91 |
-13:21:23.5 |
HIP 50476 |
22.88 |
| 2026-02-16 12:00 |
10:19:55.36 |
-13:21:16.3 |
HIP 50476 |
22.49 |
| 2026-02-17 00:00 |
10:19:53.80 |
-13:21:08.9 |
HIP 50476 |
22.10 |
| 2026-02-17 12:00 |
10:19:52.24 |
-13:21:01.5 |
HIP 50476 |
21.70 |
| 2026-02-18 00:00 |
10:19:50.68 |
-13:20:53.9 |
HIP 50476 |
21.31 |
| 2026-02-18 12:00 |
10:19:49.13 |
-13:20:46.3 |
HIP 50476 |
20.92 |
| 2026-02-19 00:00 |
10:19:47.56 |
-13:20:38.6 |
HIP 50476 |
20.53 |
| 2026-02-19 12:00 |
10:19:46.00 |
-13:20:30.8 |
HIP 50476 |
20.14 |
| 2026-02-20 00:00 |
10:19:44.44 |
-13:20:22.9 |
HIP 50476 |
19.74 |
| 2026-02-20 12:00 |
10:19:42.88 |
-13:20:14.9 |
HIP 50476 |
19.35 |
| 2026-02-21 00:00 |
10:19:41.32 |
-13:20:06.8 |
HIP 50476 |
18.96 |
| 2026-02-21 12:00 |
10:19:39.75 |
-13:19:58.6 |
HIP 50476 |
18.57 |
| 2026-02-22 00:00 |
10:19:38.19 |
-13:19:50.4 |
HIP 50476 |
18.18 |
| 2026-02-22 12:00 |
10:19:36.63 |
-13:19:42.0 |
HIP 50476 |
17.79 |
| 2026-02-23 00:00 |
10:19:35.07 |
-13:19:33.6 |
HIP 50476 |
17.40 |
| 2026-02-23 12:00 |
10:19:33.50 |
-13:19:25.1 |
HIP 50476 |
17.01 |
| 2026-02-24 00:00 |
10:19:31.94 |
-13:19:16.5 |
HIP 50476 |
16.62 |