| Parameter |
Value |
| Designation |
C/1961 R1 (Humason) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1962-12-10T05:16:13.828800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:14Z |
| Obs used |
80 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1963-05-12.0000000 |
| e |
0.98961410 |
| q (au) |
2.133470 |
| a (au) |
205.419821 |
| i (deg) |
153.277926 |
| Ω (om, deg) |
155.439541 |
| ω (w, deg) |
233.562038 |
| M (ma, deg) |
0.051146 |
Magnitude
Scatter + Global Linear
$$
M_a = (0.444 + 5.517\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
0.444 |
| n |
5.517 |
| gf |
1.000 |
| gb |
-0.889 |
| k |
0.999 |
| δ90 |
9.972 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1961-09-06 |
1962-12-03 |
+0.4532 |
-0.051 |
| 1963-01-24 |
1965-04-30 |
+1.2592 |
+0.904 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
08:28:23.64 |
+35:13:03.2 |
HIP 41554 |
12.02 |
| 2026-06-01 12:00 |
08:28:24.56 |
+35:12:56.0 |
HIP 41554 |
11.90 |
| 2026-06-02 00:00 |
08:28:25.50 |
+35:12:48.8 |
HIP 41554 |
11.79 |
| 2026-06-02 12:00 |
08:28:26.44 |
+35:12:41.5 |
HIP 41554 |
11.68 |
| 2026-06-03 00:00 |
08:28:27.40 |
+35:12:34.3 |
HIP 41554 |
11.57 |
| 2026-06-03 12:00 |
08:28:28.36 |
+35:12:27.1 |
HIP 41554 |
11.47 |
| 2026-06-04 00:00 |
08:28:29.34 |
+35:12:19.8 |
HIP 41554 |
11.37 |
| 2026-06-04 12:00 |
08:28:30.33 |
+35:12:12.6 |
HIP 41554 |
11.28 |
| 2026-06-05 00:00 |
08:28:31.32 |
+35:12:05.4 |
HIP 41554 |
11.19 |
| 2026-06-05 12:00 |
08:28:32.33 |
+35:11:58.1 |
HIP 41554 |
11.10 |
| 2026-06-06 00:00 |
08:28:33.35 |
+35:11:50.9 |
HIP 41554 |
11.02 |
| 2026-06-06 12:00 |
08:28:34.38 |
+35:11:43.6 |
HIP 41554 |
10.95 |
| 2026-06-07 00:00 |
08:28:35.42 |
+35:11:36.4 |
HIP 41554 |
10.88 |
| 2026-06-07 12:00 |
08:28:36.47 |
+35:11:29.2 |
HIP 41554 |
10.82 |
| 2026-06-08 00:00 |
08:28:37.53 |
+35:11:21.9 |
HIP 41554 |
10.76 |
| 2026-06-08 12:00 |
08:28:38.61 |
+35:11:14.7 |
HIP 41554 |
10.71 |
| 2026-06-09 00:00 |
08:28:39.69 |
+35:11:07.5 |
HIP 41554 |
10.66 |
| 2026-06-09 12:00 |
08:28:40.78 |
+35:11:00.3 |
HIP 41554 |
10.62 |
| 2026-06-10 00:00 |
08:28:41.88 |
+35:10:53.1 |
HIP 41554 |
10.59 |
| 2026-06-10 12:00 |
08:28:42.99 |
+35:10:45.8 |
HIP 41554 |
10.57 |
| 2026-06-11 00:00 |
08:28:44.11 |
+35:10:38.6 |
HIP 41554 |
10.55 |
| 2026-06-11 12:00 |
08:28:45.24 |
+35:10:31.4 |
HIP 41554 |
10.54 |
| 2026-06-12 00:00 |
08:28:46.39 |
+35:10:24.3 |
HIP 41554 |
10.53 |
| 2026-06-12 12:00 |
08:28:47.54 |
+35:10:17.1 |
HIP 41554 |
10.54 |
| 2026-06-13 00:00 |
08:28:48.70 |
+35:10:09.9 |
HIP 41554 |
10.55 |
| 2026-06-13 12:00 |
08:28:49.87 |
+35:10:02.7 |
HIP 41554 |
10.57 |
| 2026-06-14 00:00 |
08:28:51.04 |
+35:09:55.6 |
HIP 41554 |
10.60 |
| 2026-06-14 12:00 |
08:28:52.23 |
+35:09:48.4 |
HIP 41554 |
10.63 |
| 2026-06-15 00:00 |
08:28:53.43 |
+35:09:41.3 |
HIP 41554 |
10.68 |
| 2026-06-15 12:00 |
08:28:54.63 |
+35:09:34.1 |
HIP 41554 |
10.73 |
| 2026-06-16 00:00 |
08:28:55.85 |
+35:09:27.0 |
HIP 41554 |
10.79 |
| 2026-06-16 12:00 |
08:28:57.07 |
+35:09:19.9 |
HIP 41554 |
10.86 |
| 2026-06-17 00:00 |
08:28:58.31 |
+35:09:12.8 |
HIP 41554 |
10.93 |
| 2026-06-17 12:00 |
08:28:59.55 |
+35:09:05.7 |
HIP 41554 |
11.01 |
| 2026-06-18 00:00 |
08:29:00.80 |
+35:08:58.6 |
HIP 41554 |
11.11 |
| 2026-06-18 12:00 |
08:29:02.06 |
+35:08:51.6 |
HIP 41554 |
11.20 |
| 2026-06-19 00:00 |
08:29:03.32 |
+35:08:44.5 |
HIP 41554 |
11.31 |
| 2026-06-19 12:00 |
08:29:04.60 |
+35:08:37.5 |
HIP 41554 |
11.43 |
| 2026-06-20 00:00 |
08:29:05.88 |
+35:08:30.5 |
HIP 41554 |
11.55 |
| 2026-06-20 12:00 |
08:29:07.17 |
+35:08:23.5 |
HIP 41554 |
11.68 |
| 2026-06-21 00:00 |
08:29:08.47 |
+35:08:16.5 |
HIP 41554 |
11.81 |
| 2026-06-21 12:00 |
08:29:09.78 |
+35:08:09.5 |
HIP 41554 |
11.95 |
| 2026-06-22 00:00 |
08:29:11.09 |
+35:08:02.6 |
HIP 41669 |
11.83 |