| 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 |
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) |
| 2026-05-12 00:00 |
02:29:11.38 |
+13:02:42.7 |
HIP 11518 |
19.89 |
| 2026-05-12 12:00 |
02:29:12.91 |
+13:02:50.0 |
HIP 11518 |
20.18 |
| 2026-05-13 00:00 |
02:29:14.44 |
+13:02:57.3 |
HIP 11518 |
20.47 |
| 2026-05-13 12:00 |
02:29:15.97 |
+13:03:04.7 |
HIP 11518 |
20.76 |
| 2026-05-14 00:00 |
02:29:17.49 |
+13:03:11.9 |
HIP 11518 |
21.05 |
| 2026-05-14 12:00 |
02:29:19.01 |
+13:03:19.2 |
HIP 11518 |
21.35 |
| 2026-05-15 00:00 |
02:29:20.53 |
+13:03:26.5 |
HIP 11518 |
21.65 |
| 2026-05-15 12:00 |
02:29:22.05 |
+13:03:33.7 |
HIP 11518 |
21.95 |
| 2026-05-16 00:00 |
02:29:23.56 |
+13:03:40.9 |
HIP 11518 |
22.25 |
| 2026-05-16 12:00 |
02:29:25.07 |
+13:03:48.1 |
HIP 11518 |
22.55 |
| 2026-05-17 00:00 |
02:29:26.58 |
+13:03:55.2 |
HIP 11518 |
22.86 |
| 2026-05-17 12:00 |
02:29:28.08 |
+13:04:02.4 |
HIP 11518 |
23.17 |
| 2026-05-18 00:00 |
02:29:29.58 |
+13:04:09.5 |
HIP 11518 |
23.48 |
| 2026-05-18 12:00 |
02:29:31.08 |
+13:04:16.6 |
HIP 11518 |
23.79 |
| 2026-05-19 00:00 |
02:29:32.57 |
+13:04:23.6 |
HIP 11518 |
24.10 |
| 2026-05-19 12:00 |
02:29:34.06 |
+13:04:30.7 |
HIP 11518 |
24.41 |
| 2026-05-20 00:00 |
02:29:35.54 |
+13:04:37.7 |
HIP 11518 |
24.73 |
| 2026-05-20 12:00 |
02:29:37.02 |
+13:04:44.7 |
HIP 11518 |
25.04 |
| 2026-05-21 00:00 |
02:29:38.50 |
+13:04:51.6 |
HIP 11518 |
25.36 |
| 2026-05-21 12:00 |
02:29:39.97 |
+13:04:58.6 |
HIP 11518 |
25.67 |
| 2026-05-22 00:00 |
02:29:41.43 |
+13:05:05.5 |
HIP 11518 |
25.99 |
| 2026-05-22 12:00 |
02:29:42.90 |
+13:05:12.4 |
HIP 11691 |
25.93 |
| 2026-05-23 00:00 |
02:29:44.35 |
+13:05:19.2 |
HIP 11691 |
25.63 |
| 2026-05-23 12:00 |
02:29:45.81 |
+13:05:26.0 |
HIP 11691 |
25.33 |
| 2026-05-24 00:00 |
02:29:47.25 |
+13:05:32.8 |
HIP 11691 |
25.03 |
| 2026-05-24 12:00 |
02:29:48.70 |
+13:05:39.6 |
HIP 11691 |
24.73 |
| 2026-05-25 00:00 |
02:29:50.13 |
+13:05:46.3 |
HIP 11691 |
24.44 |
| 2026-05-25 12:00 |
02:29:51.57 |
+13:05:53.0 |
HIP 11691 |
24.15 |
| 2026-05-26 00:00 |
02:29:53.00 |
+13:05:59.7 |
HIP 11691 |
23.86 |
| 2026-05-26 12:00 |
02:29:54.42 |
+13:06:06.3 |
HIP 11691 |
23.57 |
| 2026-05-27 00:00 |
02:29:55.84 |
+13:06:12.9 |
HIP 11691 |
23.29 |
| 2026-05-27 12:00 |
02:29:57.25 |
+13:06:19.5 |
HIP 11691 |
23.02 |
| 2026-05-28 00:00 |
02:29:58.65 |
+13:06:26.0 |
HIP 11691 |
22.74 |
| 2026-05-28 12:00 |
02:30:00.05 |
+13:06:32.5 |
HIP 11691 |
22.47 |
| 2026-05-29 00:00 |
02:30:01.45 |
+13:06:39.0 |
HIP 11691 |
22.21 |
| 2026-05-29 12:00 |
02:30:02.84 |
+13:06:45.5 |
HIP 11691 |
21.94 |
| 2026-05-30 00:00 |
02:30:04.22 |
+13:06:51.9 |
HIP 11691 |
21.69 |
| 2026-05-30 12:00 |
02:30:05.60 |
+13:06:58.2 |
HIP 11691 |
21.43 |
| 2026-05-31 00:00 |
02:30:06.97 |
+13:07:04.6 |
HIP 11691 |
21.18 |
| 2026-05-31 12:00 |
02:30:08.34 |
+13:07:10.9 |
HIP 11691 |
20.93 |
| 2026-06-01 00:00 |
02:30:09.69 |
+13:07:17.2 |
HIP 11691 |
20.69 |
| 2026-06-01 12:00 |
02:30:11.05 |
+13:07:23.4 |
HIP 11691 |
20.45 |
| 2026-06-02 00:00 |
02:30:12.39 |
+13:07:29.6 |
HIP 11691 |
20.22 |