Comet Update 7/3/2020

stevetrucker2

Comet 2020 F3 is still in one piece and still brightening.  As in the previous update it is rounding the Sun in the fast, sharp curve that includes the Perihelion (closest approach to the Sun).

See Figure 1, below

C2020_F3_Orbit_July 2
Figure 1:  Orbit of Comet 2020 F3 generated by JPL Small Body Database Orbit Diagram Widget.  Augmented and annotated by your humble narrator.

Spaceweather.com features a four-day movie of the comet’s appearance in  the LASCO instrument onboard the Sun-watching SOHO probe.

There were at some observations, after the comet left SOHO’s field of view.  Seven are now documented in the COBS database as bright as magnitude 1.0  – comparable to the brightest stars in the sky.

See it also in the now “standard” graphic for my updates- below.

LightCurve_Calc_OBS_2020F3_7-3_ANOT
Figure 2:  The Standard Graphic.

After the SOHO data (red circle) are “conventional” telescope observations and you might think that a decline is happening.  Don’t take that to the bank, because these observations are from telescopes looking just above the horizon and just before dawn.  That is a lot of atmosphere to look through and a lot of twilight interfering.   Estimates of brightness of the comet might be inexact.

Note that:

The “Calibrated Prediction” (green dots) has about July 17th as the peak brightness.  That is based solely on the distances (Sun to Comet to Earth) and assumes that the comet reflection characteristics never change.  That is – of course – never true of comets when they warm up near the sun – emitting gas and dust chaotically.  So, why do the “prediction”?  Because then we know how much of the brightness variation may be attributed to distance alone.  We can take that effect out to study the changes in reflection characteristics…including periodic variations that must be due to rotation. 

If this sounds like an “inexact science” – good!  All Science is inexact!   However, a good Scientist can give you some idea of just how inexact his science is.   😉

Challenging the Dawn

Oscar Martín Mesonero of Salamanca, Spain, also saw the comet in morning twilight.  See his photo below (also from Spaceweather.com)

F3_low_tel_photo
Figure 3:  Mesonero’s photo of C/2020 F3

The comet is here seen as more-or-less “head on” and seems to vaguely show a bifurcated (two part) tail.  That is not unusual as gas particles may be ionized and affected by the Sun’s magnetic fields and solar wind.  The dust particles tend to stream out behind the orbital direction of the comet’s path, while still blown around by solar wind.  Sometimes the two line up as viewed from Earth, other times, not so.

Hasta Luego,

Steve

Uber Alley – Camouflage

Foreword:  I am fully aware of the stereotypical reputation of posts about cats.  So, I promise not to post anything like this again for at least a year. 😉 Posted: 6/27/2020

Some pet owners attribute human-like characteristics to their animal friends. But, some alleged domesticated cats have unique dog-like traits and other qualities that defy description.  Locally, there is this dingy-gray cat named Pepper (but referred to as the Princess, for her attitude) who is the same color as some spots on the concrete driveway.  She frequently likes to play “chicken” with the multi-ton Ford Explorer I am backing out of the garage (as I set off to drive for Uber – that’s the connection, you see).  In the pre-dawn darkness, as imaged by the back-up camera, she appears as just another spot (albeit a moving one) on the driveway.  I take great care to not let her become a literal spot on the driveway.  This is the same cat who will jump into open cabinets despite the dishes there found and climb into empty boxes (Figure 1).

Figure 1: Pepper in a box

Unlike most sane cats, she loves to get in the car and we have to tell contractors and movers in the area to double check their trucks before they leave.  She would sit outside the neighbor’s window and torture the poor dogs in the house.  She hopped in the Ford while I was unloading from a One, Two, Three, Etc. road trip and I found her as I took the car to turn it around.  So I drove her around the block instead.  Far from cowering on the floorboards, this one. See figure 2 below  

Figure 2: Not cowering on the floor

This feline is watched over by a woman who calls the cat “Princess” while referring to herself as “Abuelita” (Grandmother).  Abuelita makes every effort to comfort the Princess – even to the point of providing her with a special chair, covered with the cat’s own blanket and a pillow included.  Please see figure 3, below.

Figure 3: Luxurious repose prepared for Pepper

The Princess, however, rejects the throne and prefers to spend her time in a more rustic location.  Please see figure 4, below.

Figure 4: This is where she really wants to be.

So, this is the lunacy that (to some degree) makes the rest of life bearable.  😉

Hasta Luego,

Steve

Comet Update – 6/26/2020

Comet C/20020 F3 (hereinafter mostly referred to simply as “F3”) is now very close to the Sun as viewed from Earth.  Pointing highly complicated and hideously expensive telescopes near the sun is a process to be avoided and so there have been few observations of F3 lately. 

Let me make this perfectly clear – do not try to see the comet at this time when it is near the Sun!

On the other hand, some instruments are specifically designed to look at the part of the sky around the Sun.  One is aboard a probe called Solar and Heliospheric Observatory (SOHO*) that orbits between Earth and Sun in what is called a “halo orbit” around a “Lagrange point” (which has nothing to do with any personal service establishments in the City of La Grange, Texas).

*Note that the acronym should be SHO or SAHO, but SOHO sounded cooler so they use that.

The short story is that SOHO studies the Sun and its atmosphere and comets appear in its field of view from time to time.  F3 has made an appearance there and somebody has measured the brightness about once per day and added that to the COBS (another fractured acronym) database. 

As the comet nears the Sun, it heats up, emits more gas and dust and brightens in excess of distance effect. In the figure below, you can see that the brightness has come close to second magnitude.  Nevertheless – do not try to see it!  SOHO is out in Space and has specially designed instruments – you aren’t and don’t. There will come a time when you can look at it safely and I will be glad to tell you when.

Figure 1: Predicted vs. observed magnitude for Comet C/2020 F3

Below is the SOHO image of the comet for today, June 26.    

Figure 2: SOHO image of Comet 2020 F3 (they call it NEOWISE)

NEOWISE is a project name associated with the Wide Field Infrared Survey Explorer (WISE) which has discovered 28 comets and 313 Near Earth Objects.  That is why Your Humble Narrator does not use “NEOWISE” or any other project or imaging system name as the name of a comet (or other object), like the mundane press so often do.  Because…which one?!  You would think that the SOHO people would realize this…but NO! 😉

Update: I find that the text additions on this graphic are not from the SOHO folks, but added by a third party who shall remain nameless!

In the future, I will quote SOHO graphics myself and add any text for clarification – with attribution to myself alone.

Hasta Luego,

Steve

Uber Alley – Idle Airliners

06/20/2020

IAH is the code for Houston Intercontinental Airport.  They tried to get the coveted HIC code (for Irony’s sake), but it was already taken by Iscor Heliport in Pretoria, South Africa.  Likewise, HIA was already taken by Lianshui Airport in Huai’an China.

During the Great Communist Chinese Virus Panic of 2020,  IAH was reduced from five operating terminals to two and a unique situation took place.  Since air traffic was cut to the bone – and some sawing of the bones was underway – there was a ridiculous excess of airplanes.  And, just what does one do with such an excess?  The first thing you might think of is to put them in hangers.  However, it should occur to alert readers (all y’all) that because an airline only makes money when they keep their planes busy, there is a ridiculous shortage of hangers in the current rigamarole.

Well, airplanes (especially the busy ones) are outside probably 98% of the time and they are designed to do just that – through rain or sleet or gloom of night.  So, what you do is park your airplanes where there is secure outdoor space.  Conveniently, airports are some of the most secure outdoor spaces around and what you can do is park those idle airplanes along the aprons that line the runways.

In my Transportation Business I have occasion to visit airports – in the current narrative, IAH.  What I noticed, repeatedly – as I drove the approach to the terminals – was a long chain of airplanes along a runway apron.  I estimated their number at about thirty – because counting airplane tails while driving a passenger to his flight is considered unprofessional.

But that does not mean that I cannot deliver the passenger to his terminal and then drive out to where I can find a fence along that particular stretch. Thinking of security, I decided not to tell where this is.  Anyway, I was able to count 26 parked planes and capture some photos of same.  The view is obstructed by the fence (Figure 1), but I managed to sneak a glimpse of a few planes through the spaces in the chain-link hurricane fence (Figure 2).

Figure 1: Airplanes with not much to do
Figure 2: A view through a space in the fence grid.

Hasta Luego,

Steve

Uber Alley – Introduction

In Shakespeare’s The Tempest, a sea-change is a change brought about by sea: Full fathom five thy father lies … / Nothing of him that doth fade / But doth suffer a sea-change. This meaning is the original one, but it’s now archaic. Long after sea change had gained its figurative meaning, however, writers continued to allude to Shakespeare’s literal one; Charles Dickens, Henry David Thoreau, and P.G. Wodehouse all used the term as an object of the verb suffer.

Merriam Webster

Having discovered that six decades of life “unqualifies” me – despite over four decades of experience – my life suffered a “sea change”.

 After Going Walkabout for about five years now, it becomes obvious that I need to be my own boss.  Mostly this is because I can count on me to give me a fair break.  I won’t reject me for being old.  I won’t coerce me to violate DOT guidelines.  I won’t resent me for having more technical knowledge than me or for speaking my own language better than I do.  I won’t assign myself menial tasks (which I would cheerfully carry out, anyway) in a forlorn attempt to convince me to quit and I won’t set myself up to fail.  Yup, that’s what I learned.

My Walkabout was the result of an early – and involuntary – retirement.  It was complicated by winding up as the sole survivor among my parents, dementia suffering stepmother and cardiac-failed 59-year old sister.  

That is what happens when you continue to survive because anybody can just up and die.  Life goes on and I hope that my wife and children will live long and prosper.  Make no mistake – I fully intend to do so myself for about five more decades.  I decided at age 15 to live 100 years more.  As I am now 65 and work about 35 hours a week, swim an average of a half-mile per day, have lost about 80 pounds and I still mow my own yard – I do not think that goal to be unreasonable.    

But the post is called Uber Alley for a reason.  I am now a humble Personal Transportation Contractor and I find that every day is a unique adventure.  In that sense, it is somewhat like over-the-road (OTR) trucking. I start out at five or six in the morning from the house or the gym.  I have wound up in places like Prairie View, Pasadena, The Woodlands, Rosenburg, Needville, Texas City, Seabrook and Galveston.  While I have had some repeat passengers, I can count them on two hands – out of 1348 trips in nine months.

There is enough to write about and it promises to be just as interesting as the Going Walkabout series that started this whole imbroglio.  I stumble across things that should serve to illustrate the stories with photos and I’ll include some here, just to get started.  I won’t be posting pictures of the passengers – for obvious reasons. 

Below is the Main Street Wharf, in downtown Houston.  I was just about to go see it up   close, when another ride came in and I had to leave.  That is a lot like OTR, as well.

Figure 1:  Just pulling into a parking spot to stop and sanitize the seatbelts, I found this.
Figure 2: About the closest I got to the Wharf before another trip called.

Hasta Luego,

Steve

Comet Update 6/16/20

Comet Update C/2020 F3

Yet another comet approaches and has already been promoted as an “eyes only” event.  Not by me, of course – because I have learned the hard way that comets almost always disappoint – mostly because astronomy nerds are too quick to get excited about such things.

It is called C/2020 F3 and is approaching from the southern part of the Solar System.  I include (figure 1 below) a diagram  (made with JPL’s Small Body Orbit Diagram Utility and appropriately annotated by your Humble Narrator.)

Figure 1. Comets can originate from most any part of the sky. Many orbit near the plane of the solar system. This one does not.

As before, I have calculated the expected change of brightness due to distance alone (green curve on the graph below) and plotted the observed brightness (blue dots) for the comet. See figure 2 below.

Figure 2. You can see why comet nerds are predicting this as a spectacular sight – it has far exceeded expectations already Remember Magnitude 6 is “eyes only” brightness. One prediction in “cometnerdland” is 2 to 3.

I will be watching this one as well.  Updates as they occur.

No, you can’t see it yet and neither can I.

Hasta Luego,

Steve

Comet Update 5/26/2020

Comet 2020 F8 has dimmed well below “eyes only” visibility and seems destined for obscurity.  Now that it has passed Perigee (closest distance to the Earth) and is passing Perihelion (closest distance to the sun), there can be no expectation of brightening, based on distance alone.  Another outburst of erupted gas and dust also seems unlikely, so this is probably the end of the story for C/2020 F8. -Update: Yes, it was the end.

Figure 1. Predicted “distance only” brightness and actual observations
Figure 2: Comet’s path through the Solar System.

Next, I am thinking of a project to confirm the rotation period of a historical comet using the phase analysis as described in my  Comet Update of April 26 This will utilize that data at the Comet Observation database. It will serve as proof that I am doing this analysis correctly.

Comet Observation database (COBS) saw first light in 2010 and is maintained by Crni Vrh Observatory. It is a free and unique service for comet observers worldwide which allows submission, display and analysis of comet data in a single location.

Amateur astronomers can make valuable contributions to comet science by observing comets and submitting their observations to COBS as professional astronomers typically do not have telescope time required to acquire regular observations. We therefore encourage comet observers worldwide to submit their observations and contribute to the COBS database.”

COBS homepage

Orbit diagrams and distance info: https://ssd.jpl.nasa.gov/sbdb.cgi#top

Comet Observation database: https://cobs.si/analysis

Hasta Luego – Steve

Comet Update 5/19/2020

Comet 2020 F8 has dimmed from its last outburst and is now just barely qualified to be “eyes only visible”.  I call it that only in the abstract since I have attempted to spot it several times with binoculars without success.  I live on the west side of Houston and the place where the comet is theoretically visible is in the northeastern sky – which is awash in city-light at best – just before dawn.  My carefully chosen location is down south on a road that leads to Brazos Bend State Park where I was a volunteer telescope operator at the George Observatory.

You may ask why I did not use that telescope to view the comet.  It is that the public viewing program at “The George” was suspended late last year for renovations to the observatory and museum facilities.  It was all set for a grand re-opening when the current disruption concerning the Communist Chinese Xi Jinping Virus began.   

My attempts at viewing the comet took place on mornings this past week when skies were allegedly clear.  None were successful – due mostly to the aforementioned urban skies. The path of the comet is from the southern extreme of the Solar System – crossing into the northern skies – where it is now found – and exiting back to the south.  Because it is closer to the Sun now, it can only be seen in the early morning.  Later this month it will appear in the evening sky just after sunset.  More on that later.

The diagram in Figure 1 shows the current positions of the comet and Earth.  Mercury and Venus are seen but not labeled.  I dotted the comet’s path when it occupies the southern part of the Solar System.  With a considerable imaginative effort (and taking into account the direction of Earth and the comet), you can understand why it only appears in the early morning sky now and will appear just after sunset later. 

Figure 1: Comet’s path through the Solar System. Orbits of Mercury and Venus are shown but not labeled.

Figure 2 is the updated light curve and shows the decline in brightness.  Since it has now passed its closest point to the Earth, we could expect it to dim – if it were not still approaching the Sun.  The Sun will illuminate the comet more – and heat it, which may induce another outburst of brightness.  

Or…it could fall apart and disappear.  No guarantees, you understand. 😉

The observations are being “handed over” from southern hemisphere observers to those in the north.  That gap near the 15th is a result.  There were single observations each day, but so far from the norm that I did not bother to plot them.

Figure 2. Predicted “distance only” brightness and actual observations

Hasta Luego – Steve

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

NEO 2020 JJ 5/04/20

Another Near Earth Object encounter.  This time with a unique announcement:

Figure 1.

Notice that 2020 JJ has an anomalous distance of encounter of zero AU.  It is rounded off, of course.  The managers of this source will be contacted to encourage more decimal places!  By other sources, I find the “miss” distance to be about 16,200 miles which is indeed less than 0.1 Lunar Distances.

This, again is worthy of a more detailed diagram with a better picture of the Earth (Thanks, NASA!).

The approaching asteroid did not pass across the celestial equator – where all the geosynchronous communication satellites are – but further to the South.

The JPL Small Body Database Browser, which is also the source for the “circle and arrows” diagrams you have seen on these pages, has undoubtedly given us a more accurate figure.  However, it does have some limitations, which are clearly explained in the website:

“This orbit viewer was implemented using two-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances.”

https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2000%20CH59;old=0;orb=1;cov=0;log=0;cad=0#orb

The alert readers (most of you) will point out that “planetary encounter circumstances” is exactly what I am talking about.  That statement means that when asteroids get close to a planet, their mutual gravity has a significant effect that is not calculated in this utility.  So, that 16,200 miss distance is not keenly accurate and almost certainly too large.  Not only that, but it also means that the orbit after the near encounter will have been altered.  It will need to be recalculated and replaced in the database.

JPL has a utility for that, called the “Horizons system” and NASA has an organization to keep track of these things (and studies methods to avoid collisions) called the Planetary Defense Coordination Office.  That said, rocks this small (about 13 feet across) are not easily detected far in advance.  They are also less destructive should they fall to Earth.  This one was small compared to the Chelyabinsk meteor.