| Parameter |
Value |
| Designation |
C/2015 V2 (Johnson) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-06-12T08:20:20.423040Z |
| Orbit solution date (soln_date, UTC) |
2026-06-09T11:12:24Z |
| Obs used |
5890 |
| NEO |
- |
| M1 |
10.000 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-01-18.0000000 |
| e |
1.00170261 |
| q (au) |
1.636950 |
| a (au) |
-961.433151 |
| i (deg) |
49.874812 |
| Ω (om, deg) |
69.852100 |
| ω (w, deg) |
164.898098 |
| M (ma, deg) |
-0.004805 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.183 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.183 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-0.781 |
| k |
0.800 |
| δ90 |
10.000 |
| 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 |
| 2015-01-11 |
2017-06-11 |
+1.6631 |
-1.343 |
| 2017-06-12 |
2017-08-29 |
-9.8516 |
+0.988 |
| 2017-08-29 |
2019-10-27 |
+2.9922 |
-2.101 |
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 |
03:09:09.41 |
-17:13:05.3 |
HIP 14460 |
39.38 |
| 2026-07-29 12:00 |
03:09:10.75 |
-17:13:38.5 |
HIP 14460 |
39.46 |
| 2026-07-30 00:00 |
03:09:12.05 |
-17:14:12.0 |
HIP 14460 |
39.54 |
| 2026-07-30 12:00 |
03:09:13.30 |
-17:14:45.7 |
HIP 14460 |
39.62 |
| 2026-07-31 00:00 |
03:09:14.52 |
-17:15:19.7 |
HIP 14460 |
39.70 |
| 2026-07-31 12:00 |
03:09:15.70 |
-17:15:53.9 |
HIP 14460 |
39.78 |
| 2026-08-01 00:00 |
03:09:16.83 |
-17:16:28.3 |
HIP 14460 |
39.85 |
| 2026-08-01 12:00 |
03:09:17.92 |
-17:17:02.9 |
HIP 14460 |
39.93 |
| 2026-08-02 00:00 |
03:09:18.97 |
-17:17:37.8 |
HIP 14460 |
40.01 |
| 2026-08-02 12:00 |
03:09:19.98 |
-17:18:12.8 |
HIP 14460 |
40.08 |
| 2026-08-03 00:00 |
03:09:20.95 |
-17:18:48.1 |
HIP 14460 |
40.16 |
| 2026-08-03 12:00 |
03:09:21.88 |
-17:19:23.6 |
HIP 14460 |
40.23 |
| 2026-08-04 00:00 |
03:09:22.76 |
-17:19:59.4 |
HIP 14460 |
40.31 |
| 2026-08-04 12:00 |
03:09:23.60 |
-17:20:35.3 |
HIP 14460 |
40.38 |
| 2026-08-05 00:00 |
03:09:24.40 |
-17:21:11.4 |
HIP 14460 |
40.45 |
| 2026-08-05 12:00 |
03:09:25.16 |
-17:21:47.8 |
HIP 14460 |
40.52 |
| 2026-08-06 00:00 |
03:09:25.87 |
-17:22:24.3 |
HIP 14460 |
40.59 |
| 2026-08-06 12:00 |
03:09:26.54 |
-17:23:01.1 |
HIP 14460 |
40.66 |
| 2026-08-07 00:00 |
03:09:27.17 |
-17:23:38.0 |
HIP 14674 |
40.35 |
| 2026-08-07 12:00 |
03:09:27.76 |
-17:24:15.2 |
HIP 14674 |
39.73 |
| 2026-08-08 00:00 |
03:09:28.30 |
-17:24:52.5 |
HIP 14674 |
39.10 |
| 2026-08-08 12:00 |
03:09:28.80 |
-17:25:30.0 |
HIP 14674 |
38.47 |
| 2026-08-09 00:00 |
03:09:29.26 |
-17:26:07.7 |
HIP 14674 |
37.84 |
| 2026-08-09 12:00 |
03:09:29.67 |
-17:26:45.6 |
HIP 14674 |
37.20 |
| 2026-08-10 00:00 |
03:09:30.04 |
-17:27:23.7 |
HIP 14674 |
36.56 |
| 2026-08-10 12:00 |
03:09:30.37 |
-17:28:01.9 |
HIP 14674 |
35.92 |
| 2026-08-11 00:00 |
03:09:30.65 |
-17:28:40.4 |
HIP 14674 |
35.28 |
| 2026-08-11 12:00 |
03:09:30.89 |
-17:29:18.9 |
HIP 14674 |
34.64 |
| 2026-08-12 00:00 |
03:09:31.08 |
-17:29:57.7 |
HIP 14674 |
33.99 |
| 2026-08-12 12:00 |
03:09:31.24 |
-17:30:36.6 |
HIP 14674 |
33.34 |
| 2026-08-13 00:00 |
03:09:31.34 |
-17:31:15.7 |
HIP 14674 |
32.69 |
| 2026-08-13 12:00 |
03:09:31.41 |
-17:31:55.0 |
HIP 14674 |
32.03 |
| 2026-08-14 00:00 |
03:09:31.43 |
-17:32:34.4 |
HIP 14674 |
31.38 |
| 2026-08-14 12:00 |
03:09:31.41 |
-17:33:13.9 |
HIP 14674 |
30.72 |
| 2026-08-15 00:00 |
03:09:31.34 |
-17:33:53.6 |
HIP 14674 |
30.06 |
| 2026-08-15 12:00 |
03:09:31.23 |
-17:34:33.5 |
HIP 14674 |
29.39 |
| 2026-08-16 00:00 |
03:09:31.07 |
-17:35:13.4 |
HIP 14674 |
28.73 |
| 2026-08-16 12:00 |
03:09:30.88 |
-17:35:53.6 |
HIP 14674 |
28.06 |
| 2026-08-17 00:00 |
03:09:30.63 |
-17:36:33.8 |
HIP 14674 |
27.40 |
| 2026-08-17 12:00 |
03:09:30.35 |
-17:37:14.2 |
HIP 14674 |
26.73 |
| 2026-08-18 00:00 |
03:09:30.02 |
-17:37:54.7 |
HIP 14674 |
26.06 |
| 2026-08-18 12:00 |
03:09:29.64 |
-17:38:35.4 |
HIP 14674 |
25.38 |
| 2026-08-19 00:00 |
03:09:29.22 |
-17:39:16.1 |
HIP 14674 |
24.71 |