| 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 |
0.934 |
| 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 |
1982-10-11 |
+4.0331 |
-2.092 |
| 1982-10-11 |
1986-12-02 |
-0.1566 |
+0.588 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
02:31:45.37 |
+13:13:56.6 |
HIP 11691 |
18.36 |
| 2026-07-29 12:00 |
02:31:45.53 |
+13:13:56.7 |
HIP 11691 |
18.39 |
| 2026-07-30 00:00 |
02:31:45.67 |
+13:13:56.7 |
HIP 11691 |
18.41 |
| 2026-07-30 12:00 |
02:31:45.81 |
+13:13:56.7 |
HIP 11691 |
18.44 |
| 2026-07-31 00:00 |
02:31:45.93 |
+13:13:56.6 |
HIP 11691 |
18.46 |
| 2026-07-31 12:00 |
02:31:46.04 |
+13:13:56.5 |
HIP 11691 |
18.48 |
| 2026-08-01 00:00 |
02:31:46.14 |
+13:13:56.3 |
HIP 11691 |
18.50 |
| 2026-08-01 12:00 |
02:31:46.22 |
+13:13:56.0 |
HIP 11691 |
18.52 |
| 2026-08-02 00:00 |
02:31:46.29 |
+13:13:55.6 |
HIP 11691 |
18.54 |
| 2026-08-02 12:00 |
02:31:46.35 |
+13:13:55.2 |
HIP 11691 |
18.55 |
| 2026-08-03 00:00 |
02:31:46.39 |
+13:13:54.8 |
HIP 11691 |
18.57 |
| 2026-08-03 12:00 |
02:31:46.43 |
+13:13:54.3 |
HIP 11691 |
18.58 |
| 2026-08-04 00:00 |
02:31:46.45 |
+13:13:53.7 |
HIP 11691 |
18.59 |
| 2026-08-04 12:00 |
02:31:46.45 |
+13:13:53.0 |
HIP 11691 |
18.60 |
| 2026-08-05 00:00 |
02:31:46.45 |
+13:13:52.3 |
HIP 11691 |
18.60 |
| 2026-08-05 12:00 |
02:31:46.43 |
+13:13:51.5 |
HIP 11691 |
18.61 |
| 2026-08-06 00:00 |
02:31:46.40 |
+13:13:50.7 |
HIP 11691 |
18.61 |
| 2026-08-06 12:00 |
02:31:46.35 |
+13:13:49.8 |
HIP 11691 |
18.61 |
| 2026-08-07 00:00 |
02:31:46.30 |
+13:13:48.9 |
HIP 11691 |
18.61 |
| 2026-08-07 12:00 |
02:31:46.23 |
+13:13:47.8 |
HIP 11691 |
18.61 |
| 2026-08-08 00:00 |
02:31:46.14 |
+13:13:46.8 |
HIP 11691 |
18.61 |
| 2026-08-08 12:00 |
02:31:46.05 |
+13:13:45.6 |
HIP 11691 |
18.60 |
| 2026-08-09 00:00 |
02:31:45.94 |
+13:13:44.4 |
HIP 11691 |
18.59 |
| 2026-08-09 12:00 |
02:31:45.82 |
+13:13:43.1 |
HIP 11691 |
18.59 |
| 2026-08-10 00:00 |
02:31:45.68 |
+13:13:41.8 |
HIP 11691 |
18.58 |
| 2026-08-10 12:00 |
02:31:45.53 |
+13:13:40.4 |
HIP 11691 |
18.56 |
| 2026-08-11 00:00 |
02:31:45.37 |
+13:13:39.0 |
HIP 11691 |
18.55 |
| 2026-08-11 12:00 |
02:31:45.20 |
+13:13:37.5 |
HIP 11691 |
18.53 |
| 2026-08-12 00:00 |
02:31:45.02 |
+13:13:35.9 |
HIP 11691 |
18.52 |
| 2026-08-12 12:00 |
02:31:44.82 |
+13:13:34.2 |
HIP 11691 |
18.50 |
| 2026-08-13 00:00 |
02:31:44.60 |
+13:13:32.6 |
HIP 11691 |
18.48 |
| 2026-08-13 12:00 |
02:31:44.38 |
+13:13:30.8 |
HIP 11691 |
18.46 |
| 2026-08-14 00:00 |
02:31:44.14 |
+13:13:29.0 |
HIP 11691 |
18.43 |
| 2026-08-14 12:00 |
02:31:43.89 |
+13:13:27.1 |
HIP 11691 |
18.41 |
| 2026-08-15 00:00 |
02:31:43.63 |
+13:13:25.2 |
HIP 11691 |
18.38 |
| 2026-08-15 12:00 |
02:31:43.35 |
+13:13:23.1 |
HIP 11691 |
18.36 |
| 2026-08-16 00:00 |
02:31:43.06 |
+13:13:21.1 |
HIP 11691 |
18.33 |
| 2026-08-16 12:00 |
02:31:42.76 |
+13:13:19.0 |
HIP 11691 |
18.30 |
| 2026-08-17 00:00 |
02:31:42.45 |
+13:13:16.8 |
HIP 11691 |
18.27 |
| 2026-08-17 12:00 |
02:31:42.12 |
+13:13:14.5 |
HIP 11691 |
18.24 |
| 2026-08-18 00:00 |
02:31:41.78 |
+13:13:12.2 |
HIP 11691 |
18.20 |
| 2026-08-18 12:00 |
02:31:41.43 |
+13:13:09.9 |
HIP 11691 |
18.17 |
| 2026-08-19 00:00 |
02:31:41.07 |
+13:13:07.5 |
HIP 11691 |
18.13 |