Comet Update 4/30/20

Comet 2020 F8 is now visible with “eyes only”.  But not from the Northern Hemisphere.  I hasten to explain that the “crosshairs” appearing (below) on the brighter stars are artifacts of the telescope construction – diffractions caused by the mounting bracket of the secondary mirror.

Figure 1:  Taken by Gerald Rhemann on April 27, 2020 @ Farm Tivoli, Namibia

This is when the comet was at about magnitude 6.3.  As of this writing, 2020 F8 is showing at magnitude 5.3.  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.  I warned you that comets can’t be predicted with simple models like that and now you see what I meant.

Figure 2.  The “distance only” prediction and the observed (daily average) brightness

Again, the differences are due to eruptions of gas and dust, making a much more reflective target.  The comet now qualifies for “eyes only” visibility.  It is still something for which you would need to take a trip outside your sophisticated urban environment.  But don’t even bother because – except for my readers in the Southern Hemisphere – it is still below the southern horizon.  I am working on some sky charts for Lima, Peru. But that still requires a road trip to a dark sky.  There may be something for you city dwellers later.

Figure 3

Update May 5: In Lima, the comet is in the Eastern sky just before dawn (unfortunately looking right across the well-lit city) at about 25 degrees altitude. The sun will be rising soon so here is the standard warning: Do not look at or near the Sun with binoculars or a telescope! Blindness may result.

There is also a meteor shower this morning, coming out of the West East and streaking across toward the city ocean.* Also, look for Mars, Jupiter and Saturn together in the Southeast. There are conflicting weather reports. One says mostly clear. If that works, “Sigrid, te quito la bruma Limeña!”. Otherwise – same as usual.

*Doh!

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Hasta Luego,

Steve

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