Comet 217P/LINEAR will make its closest approach to the Sun on 20 September, at a distance of 1.23 AU.
From Cambridge on the day of perihelion it will be visible in the morning sky, becoming accessible around 02:34, when it reaches an altitude of 21° above your south-eastern horizon. It will then reach its highest point in the sky at 05:05, 31° above your southern horizon. It will be lost to dawn twilight around 05:21, 31° above your southern horizon.
The events that comprise the 2009 apparition of 217P/LINEAR are as follows:
| Date | Event |
| 20 Sep 2009 | Comet 217P/LINEAR passes perihelion |
The table below lists the times when 217P/LINEAR will be visible from Cambridge day-by-day through its apparition:
| Date | Constellation | Comet visibility |
| 30 Aug 2009 | Eridanus | Visible from 02:14 until 04:55 Highest at 04:55, 33° above S horizon |
| 01 Sep 2009 | Eridanus | Visible from 02:18 until 04:58 Highest at 04:56, 33° above S horizon |
| 03 Sep 2009 | Eridanus | Visible from 02:21 until 05:00 Highest at 04:57, 32° above S horizon |
| 05 Sep 2009 | Eridanus | Visible from 02:24 until 05:03 Highest at 04:58, 32° above S horizon |
| 07 Sep 2009 | Eridanus | Visible from 02:27 until 05:05 Highest at 04:59, 32° above S horizon |
| 09 Sep 2009 | Eridanus | Visible from 02:29 until 05:08 Highest at 04:59, 31° above S horizon |
| 11 Sep 2009 | Eridanus | Visible from 02:32 until 05:10 Highest at 05:00, 31° above S horizon |
| 13 Sep 2009 | Eridanus | Visible from 02:33 until 05:13 Highest at 05:00, 31° above S horizon |
| 15 Sep 2009 | Eridanus | Visible from 02:35 until 05:15 Highest at 04:59, 31° above S horizon |
| 17 Sep 2009 | Eridanus | Visible from 02:35 until 05:17 Highest at 04:59, 31° above S horizon |
| 19 Sep 2009 | Eridanus | Visible from 02:36 until 05:20 Highest at 04:58, 30° above S horizon |
| 21 Sep 2009 | Eridanus | Visible from 02:36 until 05:22 Highest at 04:57, 30° above S horizon |
| 23 Sep 2009 | Eridanus | Visible from 02:35 until 05:24 Highest at 04:55, 30° above S horizon |
| 25 Sep 2009 | Eridanus | Visible from 02:34 until 05:27 Highest at 04:53, 30° above S horizon |
| 27 Sep 2009 | Eridanus | Visible from 02:32 until 05:29 Highest at 04:51, 30° above S horizon |
| 29 Sep 2009 | Eridanus | Visible from 02:30 until 05:31 Highest at 04:49, 30° above S horizon |
| 01 Oct 2009 | Eridanus | Visible from 02:28 until 05:33 Highest at 04:46, 30° above S horizon |
| 03 Oct 2009 | Eridanus | Visible from 02:24 until 05:36 Highest at 04:43, 30° above S horizon |
| 05 Oct 2009 | Eridanus | Visible from 02:21 until 05:38 Highest at 04:39, 30° above S horizon |
| 07 Oct 2009 | Lepus | Visible from 02:17 until 05:40 Highest at 04:35, 30° above S horizon |
| 09 Oct 2009 | Lepus | Visible from 02:12 until 05:42 Highest at 04:31, 30° above S horizon |
A more detailed table of 217P/LINEAR's position on each night is available here. A diagram of the orbit of 217P/LINEAR is available here.
Finder chart
The chart below shows the path of 217P/LINEAR 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 217P/LINEAR is currently available.
The comet's position at perihelion will be:
| Object | Right Ascension | Declination | Constellation | Magnitude |
| Comet 217P/LINEAR | 04h18m40s | 16°05'S | Eridanus | 9.0 |
The coordinates are given in J2000.0.
The sky on 23 Nov 2024
| The sky on 23 November 2024 | ||||||||||||||||||||||||||||||||||
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37% 22 days old |
All times shown in EST.
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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 13 Oct 2024.
Image credit
© Andy Roberts 1997. Pictured comet is C/1995 O1 Hale-Bopp.