Comet 73P/Schwassmann-Wachmann reaches peak brightness

Dominic Ford, Editor
From the Comets feed


Comet 73P/Schwassmann-Wachmann is forecast to reach the brightest point in its 1990 apparition on 17 July. At that time, it will lie at a distance of 0.95 AU from the Sun, and at a distance of 0.17 AU from the Earth.

From Fairfield on 17 July it will not be readily observable since it will lie so far south that it will never rise more than 14° above the horizon.

The events that comprise the 1990 apparition of 73P/Schwassmann-Wachmann are as follows:

Date Event
02 Jul 1990Comet 73P/Schwassmann-Wachmann passes perihelion
17 Jul 1990Comet 73P/Schwassmann-Wachmann reaches peak brightness
24 Jul 1990Comet 73P/Schwassmann-Wachmann passes perigee

The table below lists the times when 73P/Schwassmann-Wachmann will be visible from Fairfield day-by-day through its apparition:

Date Constellation Comet visibility
26 Jun 1990SextansNot observable
28 Jun 1990SextansNot observable
30 Jun 1990SextansNot observable
02 Jul 1990SextansNot observable
04 Jul 1990SextansNot observable
06 Jul 1990SextansNot observable
08 Jul 1990HydraNot observable
10 Jul 1990HydraNot observable
12 Jul 1990HydraNot observable
14 Jul 1990HydraNot observable
16 Jul 1990AntliaNot observable
18 Jul 1990AntliaNot observable
20 Jul 1990AntliaNot observable
22 Jul 1990VelaNot observable
24 Jul 1990VelaNot observable
26 Jul 1990VelaNot observable
28 Jul 1990CarinaNot observable
30 Jul 1990CarinaNot observable
01 Aug 1990VolansNot observable
03 Aug 1990DoradoNot observable
05 Aug 1990DoradoNot observable

A more detailed table of 73P/Schwassmann-Wachmann's position on each night is available here. A diagram of the orbit of 73P/Schwassmann-Wachmann is available here.

Finder chart

The chart below shows the path of 73P/Schwassmann-Wachmann over the course of its apparition, as calculated from the orbital elements published by the Minor Planet Center (MPC). It is available for download, either on dark background, in PNG, PDF or SVG formats, or on a light background, in PNG, PDF or SVG formats. It was produced using StarCharter.

Comet brightnesses

Comets are intrinsically highly unpredictable objects, since their brightness depends on the scattering of sunlight from dust particles in the comet's coma and tail. This dust is continually streaming away from the comet's nucleus, and its density at any particular time is governed by the rate of sublimation of the ice in the comet's nucleus, as it is heated by the Sun's rays. It also depends on the amount of dust that is mixed in with that ice. This is very difficult to predict in advance, and can be highly variable even between successive apparitions of the same comet.

In consequence, while the future positions of comets are usually known with a high degree of confidence, their future brightnesses are not. For most comets, we do not publish any magnitude estimates at all. For the few comets where we do make estimates, we generally prefer the BAA's magnitude parameters to those published by the Minor Planet Center, since they are typically updated more often.

No estimate for the brightness of comet 73P/Schwassmann-Wachmann is currently available.

The comet's position on 17 July 1990 will be:

Object Right Ascension Declination Constellation Magnitude
Comet 73P/Schwassmann-Wachmann 09h31m10s 34°12'S Antlia 6.6

The coordinates are given in J2000.0.

The sky on 23 Nov 2024

The sky on 23 November 2024
Sunrise
06:48
Sunset
16:27
Twilight ends
18:04
Twilight begins
05:11


Waning Crescent

35%

22 days old

Planets
Rise Culm. Set
Mercury 08:37 13:04 17:30
Venus 10:14 14:41 19:08
Moon 23:20 06:15 12:58
Mars 20:49 04:12 11:35
Jupiter 17:22 00:49 08:16
Saturn 13:05 18:37 00:09
All times shown in EST.

Source

This event was automatically generated on the basis of orbital elements published by the Minor Planet Center (MPC) , and is updated whenever new elements become available. It was last updated on 23 Nov 2024.

Image credit

© Andy Roberts 1997. Pictured comet is C/1995 O1 Hale-Bopp.

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