Comet Update 5/11/20

Comet 2020 F8 is now visible with “eyes only” – but just barely.  The eruption of dust and gas that has brightened the comet so quickly has abated and the debris has apparently dispersed.   Part of that has become the  tail that is blown away by the solar wind and gas.    The tail has been divided and twisted by the Sun’s magnetic field.  Below is yet another photo by Gerald Rhemann @ Farm Tivoli, Namibia on May 4, 2020.

Figure 1:

This is when the comet was at about magnitude 5.3.  It is in fact a montage of five images. As of this writing, 2020 F8 is showing at magnitude 5.8.  You will recognize the graph below as my calculation of brightness change due to total distance (Sun/Comet/Earth) with the average daily observed magnitude. 

Below is an updated “light curve” that shows the distance-based brightness calculation with the daily average observations.  The red dotted lines show the dates when the comet will be closest to the Earth (Perigee) an closest to the Sun (Perihelion).  The green points show the combined effect on brightness due to the Sun/Comet/Earth distance.

Figure 2. The “distance only” prediction and the observed (daily average) brightness. Distance data from JPL Small Body Database Browser. Observations from Comet Observation Database.

The Comet has undergone three eruptions of brightness.  The first was the eruption of Hydrogen (it is thought) that made the comet detectable in the first place.  That part is not plotted.  The next was around April 19th.  That one complicated my rotation calculations.  The third was the recent that peaked on May 31st.

2020 F8 is crossing into the Northern Hemisphere and I will attempt to spot it with binoculars or a telescope.  If I locate it I will make sky charts for you readers.  Orbit diagram below.

Figure 3: Orbit diagram.

No doubt you are wondering what will be next.  There could be another eruption.  Comets are composed of ice and rocks. The ice can be any light elements or compounds like CO2 or water – all with differing points of sublimation (like evaporation, but straight from solid to gas).  As those ices vaporize, dust and rocks are released. 

Or, the comet could break apart and fade from view – like 2019 Y4 did recently.

Or, anything in between

That’s just the way comets are.  😉

Let me share a reader’s question:

HI Steve, 

Good article.  Have you tried to see the comet yourself, or is beyond amateurs ability to view it?

 Thanks, (Road Trip Interest Group Member)

_______________________________________________

Dear Road Trip Interest Group Member,

   The comet (2020 F8) is just now coming in to a part of the sky where it  will be visible in the Northern Hemisphere.  It will be near the square of Pegasus in the early morning.  It is low on the Eastern horizon at 5 AM now but the Sun rises soon after.  I have not yet seen it for two reasons:

1.  The City of Houston is East of where I am and drowning out the sky with city-glare.

2.  The weather is persistently cloudy.

   I have two viewing location in mind out near the George Observatory. The skies out there are darker because the neighbors all practice downward directed lighting – probably by state law since the Observatory is on state property.

   If I can get a clear morning, I will  drive out and have a look in the next few days.  I will attach a finder chart (from Sky and Telescope Website )and include same in the next update. You can use that (which shows you the position relative to the constellations) and the phone app called Heavens-Above (to find where to look  for the constellations at any moment) to find the comet.

  I won’t encourage others until I – myself – can catch a glimpse.

Hasta Luego,

Steve

Comet photo:   https://spaceweathergallery.com/indiv_upload.php?upload_id=162157

Observations:  https://cobs.si/analysis

Distance Data and Orbit diagrams: https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=C%2F2020%20F8;old=0;orb=1;cov=0;log=0;cad=0#orb

FInder Chart: https://skyandtelescope.org/wp-content/uploads/Comet_Swan_finder_1800px.jpg

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