Comet NEOWISE

Banner image credit: Jeremy Perez. C/2020 F3 (NEOWISE) - 5 July 2020, 4:09AM MST / 1109UT. http://www.perezmedia.net/beltofvenus/archives/002272.html

Comet C/2006 P1 (McNaught). Courtesy of cometwatch.co.uk

Officially known as Comet C/2020 F3 (NEOWISE), this comet is the brightest comet we have had so far for a good number of years. It is a candidate to becoming the brightest comet of the last decade or more. One of the last comets to reach good brightness was C/2006 P1 (McNaught), at minus 5.5 magnitude. Another relatively bright comet was C/2011 L4 (PANSTARRS), visible in March 2013, but this one didn't live up to expectations. Since then, there as been what some call a "bright comet drought" that has lasted until the end of 2019.

Comet NEOWISE is bright but will be somewhat difficult to observe from some locations due to horizon clouds, the twilight in the morning/evening hours, and its low altitude over the horizon.

Discovery

In the past, most of the comet discoveries were made by professional or amateur astronomers who dedicated part of their time to "comet hunting" either observationally or by analyzing and comparing images of the sky captured by them. The names of such comets would follow the standards used by the International Astronomical Union and would also include the last name of the discoverer(s).

However, since a couple of decades ago, various organizations have launched or deployed ground- or space-based systems that help us survey the sky in search of near Earth objects (NEOs). Some of these projects include PanSTARRS, LINEAR, and LONEOS.

The project that discovered this particular comet is NEOWISE (for NEO "Wide-field Infrared Survey Explorer"), a mission that since 2013 has the goal of helping to "learn more about the population of near-Earth objects and comets that could pose an impact hazard to the Earth."

This is the Minor Planet Electronic Circular dated April 1, 2020, that contains the initial report and observations of comet NEOWISE: https://www.minorplanetcenter.net/mpec/K20/K20G05.html

For more information about "What is NEOWISE?", please visit https://neowise.ipac.caltech.edu/

Additional background on NEOWISE can be found at NASA: https://www.nasa.gov/mission_pages/neowise/mission/index.html

You can also read about NASA's NEO Search Program in this page: https://cneos.jpl.nasa.gov/about/search_program.html

The WISE flight system in its operational configuration. Courtesy of Caltech.

What to expect

As the comet goes beyond its closest point to the Sun, also called "perihelion", the orbit geometries of the comet and Earth will be such that it will be visible before sunrise for latitudes above 57 degrees south during July 2020.

Because it will be moving away from the Sun, it is expected that it will get fainter and fainter as days go by. But there is no way to know for sure. Comets behave differently and that's what's fascinating about them. Some comets simply break up and disintegrate around perihelion. Some others survive and have outbursts of material and become unexpectedly bright for a few days or weeks.

If comet NEOWISE survives perihelion on July 3, it will be interesting to see its behavior and the types of tails it may develop. There have been already some photos taken by amateur astronomers that show a bright tail of dust and a blueish fainter one of gas.

The celestial path of the comet is available on the image in this subsection. The finder chart is displayed for Universal Time and equatorial coordinates. If you find it useful, I can generate other maps for later weeks and months, especially if we receive a surprise and the comet delivers a good show. Just let me know via Twitter @astrodrayer.

Finder Chart and Orbit Diagram

The comet will be visible in the early morning and then the early evening for north latitudes in July 2020. Below is the finder chart for the comet with positions marked for each date at 00:00 UT. The coordinates are Earth equatorial. A few stars are named for additional reference. Below is the local path from August 20 (top right) to September 12 (bottom left) as seen at 8PM Eastern Daylight-saving Time (EDT) from New England. (Notation = DD:HH Universal Time). The diagram was generated with Starry Night Pro 8.

Orbit Diagram

The NEOWISE comet is coming from the south of the ecliptic plane of our Solar System and is reaching perihelion on July 3, 2020. It will orbit the Sun north of the ecliptic plane and swing back south as it leaves the Solar System. The diagram below was generated with Celestron Starry Night 8 Special Edition.