C/1980 E1 (Bowell)
| Parameter |
Value |
| Designation |
C/1980 E1 (Bowell) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1982-03-12T06:53:06.725760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:29Z |
| Obs used |
187 |
| NEO |
- |
| M1 |
5.800 |
| K1 |
7.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1982-01-03.0000000 |
| e |
1.05773287 |
| q (au) |
3.363940 |
| a (au) |
-58.267328 |
| i (deg) |
1.661742 |
| Ω (om, deg) |
114.557492 |
| ω (w, deg) |
135.083294 |
| M (ma, deg) |
-0.151323 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.115 + 2.337\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.115 |
| n |
2.337 |
| gf |
0.926 |
| gb |
-0.841 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1980-02-11 |
1981-05-06 |
+4.8533 |
-3.657 |
| 1981-05-06 |
1982-03-05 |
-7.7973 |
+4.010 |
| 1982-03-15 |
1983-08-10 |
+3.7733 |
-1.991 |
| 1983-08-10 |
1984-09-09 |
-9.4127 |
+8.488 |
| 1984-09-09 |
1986-12-02 |
+3.0068 |
-3.011 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
02:25:28.95 |
+12:43:16.5 |
HIP 11280 |
8.13 |
| 2026-02-03 12:00 |
02:25:29.14 |
+12:43:18.1 |
HIP 11280 |
8.12 |
| 2026-02-04 00:00 |
02:25:29.35 |
+12:43:19.8 |
HIP 11280 |
8.12 |
| 2026-02-04 12:00 |
02:25:29.56 |
+12:43:21.6 |
HIP 11280 |
8.11 |
| 2026-02-05 00:00 |
02:25:29.79 |
+12:43:23.5 |
HIP 11280 |
8.10 |
| 2026-02-05 12:00 |
02:25:30.04 |
+12:43:25.4 |
HIP 11280 |
8.10 |
| 2026-02-06 00:00 |
02:25:30.29 |
+12:43:27.4 |
HIP 11280 |
8.09 |
| 2026-02-06 12:00 |
02:25:30.56 |
+12:43:29.4 |
HIP 11280 |
8.09 |
| 2026-02-07 00:00 |
02:25:30.85 |
+12:43:31.5 |
HIP 11280 |
8.09 |
| 2026-02-07 12:00 |
02:25:31.14 |
+12:43:33.7 |
HIP 11280 |
8.08 |
| 2026-02-08 00:00 |
02:25:31.46 |
+12:43:36.0 |
HIP 11280 |
8.08 |
| 2026-02-08 12:00 |
02:25:31.78 |
+12:43:38.3 |
HIP 11280 |
8.09 |
| 2026-02-09 00:00 |
02:25:32.12 |
+12:43:40.6 |
HIP 11280 |
8.09 |
| 2026-02-09 12:00 |
02:25:32.47 |
+12:43:43.1 |
HIP 11280 |
8.09 |
| 2026-02-10 00:00 |
02:25:32.83 |
+12:43:45.6 |
HIP 11280 |
8.10 |
| 2026-02-10 12:00 |
02:25:33.21 |
+12:43:48.1 |
HIP 11280 |
8.11 |
| 2026-02-11 00:00 |
02:25:33.60 |
+12:43:50.8 |
HIP 11280 |
8.12 |
| 2026-02-11 12:00 |
02:25:34.00 |
+12:43:53.5 |
HIP 11280 |
8.13 |
| 2026-02-12 00:00 |
02:25:34.42 |
+12:43:56.2 |
HIP 11280 |
8.14 |
| 2026-02-12 12:00 |
02:25:34.85 |
+12:43:59.0 |
HIP 11280 |
8.16 |
| 2026-02-13 00:00 |
02:25:35.29 |
+12:44:01.9 |
HIP 11280 |
8.18 |
| 2026-02-13 12:00 |
02:25:35.74 |
+12:44:04.9 |
HIP 11280 |
8.20 |
| 2026-02-14 00:00 |
02:25:36.21 |
+12:44:07.9 |
HIP 11280 |
8.23 |
| 2026-02-14 12:00 |
02:25:36.69 |
+12:44:10.9 |
HIP 11280 |
8.25 |
| 2026-02-15 00:00 |
02:25:37.19 |
+12:44:14.1 |
HIP 11280 |
8.28 |
| 2026-02-15 12:00 |
02:25:37.69 |
+12:44:17.3 |
HIP 11280 |
8.32 |
| 2026-02-16 00:00 |
02:25:38.21 |
+12:44:20.5 |
HIP 11280 |
8.35 |
| 2026-02-16 12:00 |
02:25:38.75 |
+12:44:23.8 |
HIP 11280 |
8.39 |
| 2026-02-17 00:00 |
02:25:39.29 |
+12:44:27.2 |
HIP 11280 |
8.44 |
| 2026-02-17 12:00 |
02:25:39.85 |
+12:44:30.6 |
HIP 11280 |
8.48 |
| 2026-02-18 00:00 |
02:25:40.42 |
+12:44:34.1 |
HIP 11280 |
8.54 |
| 2026-02-18 12:00 |
02:25:41.01 |
+12:44:37.7 |
HIP 11280 |
8.59 |
| 2026-02-19 00:00 |
02:25:41.60 |
+12:44:41.3 |
HIP 11280 |
8.65 |
| 2026-02-19 12:00 |
02:25:42.21 |
+12:44:45.0 |
HIP 11280 |
8.71 |
| 2026-02-20 00:00 |
02:25:42.83 |
+12:44:48.7 |
HIP 11280 |
8.78 |
| 2026-02-20 12:00 |
02:25:43.47 |
+12:44:52.5 |
HIP 11280 |
8.85 |
| 2026-02-21 00:00 |
02:25:44.11 |
+12:44:56.4 |
HIP 11280 |
8.92 |
| 2026-02-21 12:00 |
02:25:44.77 |
+12:45:00.3 |
HIP 11280 |
9.00 |
| 2026-02-22 00:00 |
02:25:45.44 |
+12:45:04.2 |
HIP 11280 |
9.08 |
| 2026-02-22 12:00 |
02:25:46.12 |
+12:45:08.3 |
HIP 11280 |
9.17 |
| 2026-02-23 00:00 |
02:25:46.82 |
+12:45:12.3 |
HIP 11280 |
9.26 |
| 2026-02-23 12:00 |
02:25:47.52 |
+12:45:16.5 |
HIP 11280 |
9.36 |
| 2026-02-24 00:00 |
02:25:48.24 |
+12:45:20.7 |
HIP 11280 |
9.46 |