| 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) |
| 2026-07-29 00:00 |
10:18:24.69 |
-12:36:19.4 |
HIP 50536 |
13.55 |
| 2026-07-29 12:00 |
10:18:26.07 |
-12:36:22.1 |
HIP 50536 |
13.25 |
| 2026-07-30 00:00 |
10:18:27.45 |
-12:36:24.9 |
HIP 50536 |
12.96 |
| 2026-07-30 12:00 |
10:18:28.84 |
-12:36:27.8 |
HIP 50536 |
12.66 |
| 2026-07-31 00:00 |
10:18:30.23 |
-12:36:30.8 |
HIP 50536 |
12.36 |
| 2026-07-31 12:00 |
10:18:31.63 |
-12:36:33.9 |
HIP 50536 |
12.07 |
| 2026-08-01 00:00 |
10:18:33.03 |
-12:36:37.1 |
HIP 50536 |
11.78 |
| 2026-08-01 12:00 |
10:18:34.44 |
-12:36:40.3 |
HIP 50536 |
11.49 |
| 2026-08-02 00:00 |
10:18:35.85 |
-12:36:43.7 |
HIP 50536 |
11.21 |
| 2026-08-02 12:00 |
10:18:37.27 |
-12:36:47.2 |
HIP 50536 |
10.93 |
| 2026-08-03 00:00 |
10:18:38.69 |
-12:36:50.8 |
HIP 50536 |
10.65 |
| 2026-08-03 12:00 |
10:18:40.12 |
-12:36:54.5 |
HIP 50536 |
10.38 |
| 2026-08-04 00:00 |
10:18:41.55 |
-12:36:58.2 |
HIP 50536 |
10.11 |
| 2026-08-04 12:00 |
10:18:42.99 |
-12:37:02.1 |
HIP 50536 |
9.85 |
| 2026-08-05 00:00 |
10:18:44.43 |
-12:37:06.0 |
HIP 50536 |
9.59 |
| 2026-08-05 12:00 |
10:18:45.88 |
-12:37:10.1 |
HIP 50536 |
9.34 |
| 2026-08-06 00:00 |
10:18:47.33 |
-12:37:14.3 |
HIP 50536 |
9.10 |
| 2026-08-06 12:00 |
10:18:48.78 |
-12:37:18.5 |
HIP 50536 |
8.87 |
| 2026-08-07 00:00 |
10:18:50.24 |
-12:37:22.8 |
HIP 50536 |
8.64 |
| 2026-08-07 12:00 |
10:18:51.70 |
-12:37:27.3 |
HIP 50536 |
8.43 |
| 2026-08-08 00:00 |
10:18:53.17 |
-12:37:31.8 |
HIP 50536 |
8.22 |
| 2026-08-08 12:00 |
10:18:54.64 |
-12:37:36.4 |
HIP 50536 |
8.03 |
| 2026-08-09 00:00 |
10:18:56.11 |
-12:37:41.2 |
HIP 50536 |
7.85 |
| 2026-08-09 12:00 |
10:18:57.59 |
-12:37:46.0 |
HIP 50536 |
7.69 |
| 2026-08-10 00:00 |
10:18:59.07 |
-12:37:50.9 |
HIP 50536 |
7.54 |
| 2026-08-10 12:00 |
10:19:00.55 |
-12:37:55.9 |
HIP 50536 |
7.41 |
| 2026-08-11 00:00 |
10:19:02.04 |
-12:38:01.0 |
HIP 50536 |
7.29 |
| 2026-08-11 12:00 |
10:19:03.53 |
-12:38:06.2 |
HIP 50536 |
7.20 |
| 2026-08-12 00:00 |
10:19:05.02 |
-12:38:11.4 |
HIP 50536 |
7.12 |
| 2026-08-12 12:00 |
10:19:06.51 |
-12:38:16.8 |
HIP 50536 |
7.06 |
| 2026-08-13 00:00 |
10:19:08.01 |
-12:38:22.3 |
HIP 50536 |
7.03 |
| 2026-08-13 12:00 |
10:19:09.52 |
-12:38:27.8 |
HIP 50536 |
7.01 |
| 2026-08-14 00:00 |
10:19:11.02 |
-12:38:33.5 |
HIP 50536 |
7.02 |
| 2026-08-14 12:00 |
10:19:12.53 |
-12:38:39.2 |
HIP 50536 |
7.05 |
| 2026-08-15 00:00 |
10:19:14.03 |
-12:38:45.0 |
HIP 50536 |
7.10 |
| 2026-08-15 12:00 |
10:19:15.55 |
-12:38:50.9 |
HIP 50536 |
7.17 |
| 2026-08-16 00:00 |
10:19:17.06 |
-12:38:56.9 |
HIP 50536 |
7.26 |
| 2026-08-16 12:00 |
10:19:18.57 |
-12:39:03.0 |
HIP 50536 |
7.38 |
| 2026-08-17 00:00 |
10:19:20.09 |
-12:39:09.2 |
HIP 50536 |
7.51 |
| 2026-08-17 12:00 |
10:19:21.61 |
-12:39:15.4 |
HIP 50536 |
7.66 |
| 2026-08-18 00:00 |
10:19:23.13 |
-12:39:21.8 |
HIP 50536 |
7.83 |
| 2026-08-18 12:00 |
10:19:24.66 |
-12:39:28.2 |
HIP 50536 |
8.01 |
| 2026-08-19 00:00 |
10:19:26.18 |
-12:39:34.7 |
HIP 50536 |
8.21 |