C/1987 B1 (Nishikawa-Takamizawa-Tago)
| Parameter |
Value |
| Designation |
C/1987 B1 (Nishikawa-Takamizawa-Tago) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1987-03-17T08:17:23.208000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:33Z |
| Obs used |
87 |
| NEO |
- |
| M1 |
7.500 |
| K1 |
5.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1987-02-26.0000000 |
| e |
0.99579827 |
| q (au) |
0.869588 |
| a (au) |
206.959563 |
| i (deg) |
172.229985 |
| Ω (om, deg) |
176.010516 |
| ω (w, deg) |
200.401841 |
| M (ma, deg) |
359.993596 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.239 + 4.350\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.239 |
| n |
4.350 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.998 |
| 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 |
11:20:35.18 |
+05:24:21.2 |
HIP 55321 |
21.82 |
| 2026-02-03 12:00 |
11:20:33.66 |
+05:24:31.3 |
HIP 55321 |
21.73 |
| 2026-02-04 00:00 |
11:20:32.13 |
+05:24:41.5 |
HIP 55321 |
21.65 |
| 2026-02-04 12:00 |
11:20:30.59 |
+05:24:51.7 |
HIP 55321 |
21.58 |
| 2026-02-05 00:00 |
11:20:29.04 |
+05:25:01.9 |
HIP 55321 |
21.51 |
| 2026-02-05 12:00 |
11:20:27.49 |
+05:25:12.3 |
HIP 55321 |
21.46 |
| 2026-02-06 00:00 |
11:20:25.92 |
+05:25:22.6 |
HIP 55321 |
21.41 |
| 2026-02-06 12:00 |
11:20:24.35 |
+05:25:33.1 |
HIP 55321 |
21.36 |
| 2026-02-07 00:00 |
11:20:22.76 |
+05:25:43.6 |
HIP 55321 |
21.33 |
| 2026-02-07 12:00 |
11:20:21.17 |
+05:25:54.1 |
HIP 55321 |
21.31 |
| 2026-02-08 00:00 |
11:20:19.57 |
+05:26:04.7 |
HIP 55321 |
21.29 |
| 2026-02-08 12:00 |
11:20:17.96 |
+05:26:15.3 |
HIP 55321 |
21.28 |
| 2026-02-09 00:00 |
11:20:16.34 |
+05:26:26.0 |
HIP 55321 |
21.28 |
| 2026-02-09 12:00 |
11:20:14.72 |
+05:26:36.7 |
HIP 55321 |
21.29 |
| 2026-02-10 00:00 |
11:20:13.08 |
+05:26:47.4 |
HIP 55321 |
21.31 |
| 2026-02-10 12:00 |
11:20:11.44 |
+05:26:58.3 |
HIP 55321 |
21.34 |
| 2026-02-11 00:00 |
11:20:09.79 |
+05:27:09.1 |
HIP 55321 |
21.38 |
| 2026-02-11 12:00 |
11:20:08.14 |
+05:27:20.0 |
HIP 55321 |
21.43 |
| 2026-02-12 00:00 |
11:20:06.48 |
+05:27:30.9 |
HIP 55321 |
21.49 |
| 2026-02-12 12:00 |
11:20:04.80 |
+05:27:41.9 |
HIP 55321 |
21.55 |
| 2026-02-13 00:00 |
11:20:03.13 |
+05:27:52.9 |
HIP 55321 |
21.63 |
| 2026-02-13 12:00 |
11:20:01.44 |
+05:28:04.0 |
HIP 55321 |
21.72 |
| 2026-02-14 00:00 |
11:19:59.75 |
+05:28:15.1 |
HIP 55321 |
21.81 |
| 2026-02-14 12:00 |
11:19:58.05 |
+05:28:26.2 |
HIP 55321 |
21.92 |
| 2026-02-15 00:00 |
11:19:56.35 |
+05:28:37.4 |
HIP 55321 |
22.03 |
| 2026-02-15 12:00 |
11:19:54.64 |
+05:28:48.6 |
HIP 55321 |
22.16 |
| 2026-02-16 00:00 |
11:19:52.92 |
+05:28:59.8 |
HIP 55321 |
22.29 |
| 2026-02-16 12:00 |
11:19:51.19 |
+05:29:11.1 |
HIP 55321 |
22.43 |
| 2026-02-17 00:00 |
11:19:49.46 |
+05:29:22.4 |
HIP 55321 |
22.58 |
| 2026-02-17 12:00 |
11:19:47.73 |
+05:29:33.8 |
HIP 55321 |
22.75 |
| 2026-02-18 00:00 |
11:19:45.99 |
+05:29:45.1 |
HIP 55321 |
22.92 |
| 2026-02-18 12:00 |
11:19:44.24 |
+05:29:56.5 |
HIP 55321 |
23.10 |
| 2026-02-19 00:00 |
11:19:42.49 |
+05:30:08.0 |
HIP 55321 |
23.28 |
| 2026-02-19 12:00 |
11:19:40.73 |
+05:30:19.4 |
HIP 55321 |
23.48 |
| 2026-02-20 00:00 |
11:19:38.97 |
+05:30:30.9 |
HIP 55321 |
23.69 |
| 2026-02-20 12:00 |
11:19:37.20 |
+05:30:42.4 |
HIP 55321 |
23.90 |
| 2026-02-21 00:00 |
11:19:35.43 |
+05:30:54.0 |
HIP 55321 |
24.12 |
| 2026-02-21 12:00 |
11:19:33.65 |
+05:31:05.5 |
HIP 55321 |
24.35 |
| 2026-02-22 00:00 |
11:19:31.87 |
+05:31:17.1 |
HIP 55321 |
24.59 |
| 2026-02-22 12:00 |
11:19:30.08 |
+05:31:28.7 |
HIP 55321 |
24.83 |
| 2026-02-23 00:00 |
11:19:28.29 |
+05:31:40.4 |
HIP 55321 |
25.09 |
| 2026-02-23 12:00 |
11:19:26.49 |
+05:31:52.0 |
HIP 55321 |
25.35 |
| 2026-02-24 00:00 |
11:19:24.70 |
+05:32:03.7 |
HIP 55321 |
25.61 |