| Parameter |
Value |
| Designation |
C/1931 O1 (Nagata) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1931-06-11T17:58:51.191040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:03Z |
| Obs used |
33 |
| NEO |
- |
| M1 |
5.700 |
| K1 |
4.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1931-10-05.0000000 |
| e |
0.97845116 |
| q (au) |
1.046195 |
| a (au) |
48.549944 |
| i (deg) |
42.302413 |
| Ω (om, deg) |
192.252622 |
| ω (w, deg) |
320.091135 |
| M (ma, deg) |
0.335788 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.469 + 3.539\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.469 |
| n |
3.539 |
| gf |
0.994 |
| gb |
-0.700 |
| k |
0.800 |
| δ90 |
9.971 |
| 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) |
| 2026-09-20 00:00 |
21:49:27.44 |
+17:07:12.1 |
HIP 107788 |
14.00 |
| 2026-09-20 12:00 |
21:49:26.28 |
+17:07:01.0 |
HIP 107788 |
14.32 |
| 2026-09-21 00:00 |
21:49:25.14 |
+17:06:49.9 |
HIP 107788 |
14.65 |
| 2026-09-21 12:00 |
21:49:24.00 |
+17:06:38.8 |
HIP 107788 |
14.97 |
| 2026-09-22 00:00 |
21:49:22.87 |
+17:06:27.5 |
HIP 107788 |
15.30 |
| 2026-09-22 12:00 |
21:49:21.74 |
+17:06:16.3 |
HIP 107788 |
15.62 |
| 2026-09-23 00:00 |
21:49:20.62 |
+17:06:05.0 |
HIP 107788 |
15.94 |
| 2026-09-23 12:00 |
21:49:19.51 |
+17:05:53.6 |
HIP 107788 |
16.27 |
| 2026-09-24 00:00 |
21:49:18.41 |
+17:05:42.2 |
HIP 107788 |
16.59 |
| 2026-09-24 12:00 |
21:49:17.31 |
+17:05:30.8 |
HIP 107788 |
16.91 |
| 2026-09-25 00:00 |
21:49:16.22 |
+17:05:19.3 |
HIP 107788 |
17.23 |
| 2026-09-25 12:00 |
21:49:15.14 |
+17:05:07.8 |
HIP 107788 |
17.55 |
| 2026-09-26 00:00 |
21:49:14.06 |
+17:04:56.2 |
HIP 107788 |
17.87 |
| 2026-09-26 12:00 |
21:49:12.99 |
+17:04:44.6 |
HIP 107788 |
18.19 |
| 2026-09-27 00:00 |
21:49:11.93 |
+17:04:33.0 |
HIP 107788 |
18.51 |
| 2026-09-27 12:00 |
21:49:10.88 |
+17:04:21.3 |
HIP 107788 |
18.82 |
| 2026-09-28 00:00 |
21:49:09.83 |
+17:04:09.6 |
HIP 107788 |
19.14 |
| 2026-09-28 12:00 |
21:49:08.80 |
+17:03:57.8 |
HIP 107788 |
19.45 |
| 2026-09-29 00:00 |
21:49:07.77 |
+17:03:46.0 |
HIP 107788 |
19.77 |
| 2026-09-29 12:00 |
21:49:06.74 |
+17:03:34.2 |
HIP 107788 |
20.08 |
| 2026-09-30 00:00 |
21:49:05.73 |
+17:03:22.3 |
HIP 107788 |
20.39 |
| 2026-09-30 12:00 |
21:49:04.72 |
+17:03:10.4 |
HIP 107788 |
20.70 |
| 2026-10-01 00:00 |
21:49:03.73 |
+17:02:58.5 |
HIP 107788 |
21.01 |
| 2026-10-01 12:00 |
21:49:02.74 |
+17:02:46.6 |
HIP 107788 |
21.32 |
| 2026-10-02 00:00 |
21:49:01.75 |
+17:02:34.6 |
HIP 107788 |
21.63 |
| 2026-10-02 12:00 |
21:49:00.78 |
+17:02:22.6 |
HIP 107788 |
21.94 |
| 2026-10-03 00:00 |
21:48:59.82 |
+17:02:10.5 |
HIP 107788 |
22.24 |
| 2026-10-03 12:00 |
21:48:58.86 |
+17:01:58.4 |
HIP 107788 |
22.55 |
| 2026-10-04 00:00 |
21:48:57.91 |
+17:01:46.3 |
HIP 107788 |
22.85 |
| 2026-10-04 12:00 |
21:48:56.98 |
+17:01:34.2 |
HIP 107788 |
23.15 |
| 2026-10-05 00:00 |
21:48:56.05 |
+17:01:22.0 |
HIP 107788 |
23.45 |
| 2026-10-05 12:00 |
21:48:55.12 |
+17:01:09.9 |
HIP 107788 |
23.75 |
| 2026-10-06 00:00 |
21:48:54.21 |
+17:00:57.7 |
HIP 107788 |
24.05 |
| 2026-10-06 12:00 |
21:48:53.31 |
+17:00:45.4 |
HIP 107788 |
24.35 |
| 2026-10-07 00:00 |
21:48:52.42 |
+17:00:33.2 |
HIP 107788 |
24.64 |
| 2026-10-07 12:00 |
21:48:51.53 |
+17:00:20.9 |
HIP 107788 |
24.94 |
| 2026-10-08 00:00 |
21:48:50.66 |
+17:00:08.6 |
HIP 107788 |
25.23 |
| 2026-10-08 12:00 |
21:48:49.79 |
+16:59:56.3 |
HIP 107788 |
25.52 |
| 2026-10-09 00:00 |
21:48:48.93 |
+16:59:44.0 |
HIP 107788 |
25.81 |
| 2026-10-09 12:00 |
21:48:48.09 |
+16:59:31.6 |
HIP 107788 |
26.10 |
| 2026-10-10 00:00 |
21:48:47.25 |
+16:59:19.3 |
HIP 107788 |
26.39 |
| 2026-10-10 12:00 |
21:48:46.42 |
+16:59:06.9 |
HIP 107788 |
26.67 |
| 2026-10-11 00:00 |
21:48:45.60 |
+16:58:54.5 |
HIP 107788 |
26.96 |