The Photoheliograph, pt. 1

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Chasing the Sun

For the entirety of the Victorian era, British gentleman scientists, gathered in the great halls (and back-rooms) of learned societies, were a driving force in the advancement of astronomy.  Much of the research was undertaken by the wealthy. These men could afford the equipment, and had the time to utilize it. It was considered their duty to use their means to promote and advance science.

1844 meeting of the BAAS
Credit: Wellcome Collection

I have a fascination with the Kew Observatory, in London. It was set up originally so that King George III could watch the Transit of Venus in 1769. The building sat empty until 1842 when the British Association for the Advancement of Science started installing various instruments ranging from self recording magnetometers to a solar telescope. It is, in fact the latter that piqued my interest.

Kew Observatory

Original Kings Observatory. Credit: The Kings Observatory website

The Sun in the mid 19th century was to become one of the greatest research subjects for several decades. It had been known for centuries that the Sun had changing spots, and through observation during eclipses has an atmosphere of sorts. In the 1850s celestial photography, while in its infancy was gaining a reputation for accurate representations of the heavenly bodies that occupy our solar system.

John Herschel

Drawing of John Herschel, published in 1846. Credit: Public Domain.

Sir John Herschel, himself a photographic scientist and astronomer urged, in April of 1854 the construction of a camera with the sole purpose of photographing the sun. He wrote to The British association For the Advancement of Science (BAAS): “With regard to proper preparations of paper, or the use of collodion, &c., the photographic art is now so much advanced that no difficulty can arise in fixing upon fitting preparations,or in the manipulations necessary for multiplying them. But it would be very requisite that many impressions of each day's work should be taken and distributed, and an interchange kept up among observers.” He envisioned several solar observatories located in different longitudes to photograph daily, and share the data so to compare them. Any differences would be apparent.

At the time, the solar corona was a hypothesis, and granulationon the surface was left to the interpretation of an artist. He suggests sensitized paper or “collodionized” glass (Report of the 24th meeting of the BAAS 1853-54) Having researched the state of the art photographic media of the time, he was on the leading edge of scientific photography. He suggested, among other things a “pretty large” 3” objective, a large photographic plate, and crosshairs to measure angles on the disc.

The somewhat ambitious project was taken up by the committee in charge of the observatory at Kew Gardens. Kew had been built some 85 years previous to observe the transit of Venus. The British Association For the Advancement of Science had taken over in 1842. It was being used for chronometer, sextant, and barometer calibration. Kew instrumentation was considered some of the best in the world. Other studies at the time of Herschel’s proposal involved terrestrial magnetism, and meteorological studies.

De la Rue

De la Rue. Credit: Burndy Library, Norwalk, Conn.

The man chosen to lead this project was Warren De La Rue. He was a successful businessman, and an avid scientist. Indeed his private observatory boasted many enviable instruments that a college observatory today would want to use. Not only were his scientific and business prowess thought of when choosing him to take this on, but also his use of the new collodion photographic process for photographing the moon and planets. (though later he would wonder if solar photography would better suit the Daguerreotype process). He appears, by all accounts to be enthusiastic about the many scientific endeavours he undertook. It seems he approached this project with gusto, ensuring the best possible outcome.

Design and construction of the solar photographic telescope began in 1854. The Andrew Ross co was hired to build the instrument. The estimated cost was £180. The Kew committee allocated £150, and Benjamin Oliveira, M.P. and fellow of the Society donated another £100 over 2 years. It was finished by the meeting of the Society in 1856. This meeting covered 1855/56. In the meantime, the Kew Observatory was being prepared to receive what by this time was called the Kew Photoheliograph. The electrical and magnetic measuring equipment was consolidated, and wind, solar, and atmospheric clarity were measured to ensure this was the best place for the telescope.

The Kew Photoheliograph

The Kew Photoheliograph. From The Engineer, 23 Feb 1866 p.137

Several changes were made by Ross to the telescope during construction. Initially a separate dome with a darkroom was to be erected, 12 feet in diameter. The focusing screen was to be 8 feet away, as Herschel’s original proposal indicated that the screen be 5 feet on a side. It was decided to use the existing 10 foot observatory dome. During the intervening months, it must of been decided that such a mammoth photograph was not needed, owing to the much smaller 12” screen on the finished telescope.

The report of 1856/57 describes the completed instrument. It is approx. 5 feet long, and pyramidal in shape with the objective end being 4” and the plate holding end 12”. The lens, made by Ross was a 3.4” diameter f/14.7 undercorrected Achromat. The undercorrection was to provide a better chemical focus, eliminating the need to focus optically, then move the plate forward to be on the same plane as the blue end of the solar spectrum.

The design of the telescope was thus: the objective focused to an ordinary Huygens eyepiece. This projected the focused image of the sun onto the photographic plate. By changing the focal length of the eyepiece the diameter of the image could be changed. Also included inside the instrument was a crosshair made of platinum wire and held tight with springs. This was set midway through the focus of the eyepiece. The photographic plate holder was ordinary, as found in cameras of the day.

The mount was a German Equatorial style made of solid gunmetal, a bronze alloy. The angle was fixed, as the telescope mount was a permanent one, and was mounted on a cast iron pedestal inside the observatory dome. The tracking was weight driven clockwork with a conical friction clutch to control the speed. By 1857 the Photoheliograph was installed, and the recording attempts started.

Expanding Universe? Hogwash!(?)

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In my last post we discussed why astronomers say “The universe is expanding.” But there is something important that we did not discuss in the last post. And that is this:

We do not actually see the universe expanding.

What do I mean by this? As stated in the previous post, when astronomers say the universe is expanding, they do not mean that everything is expanding. For example, the Earth, your hand, and the distance between Venus and the sun are all not expanding. What is expanding is the distance between galaxies. Galaxies are moving away from each other.

Or so we think.

The problem is, galaxies move so slowly, compared to their size. A galaxy can measure 100,000 light years across—in other words, a galaxy can be so large that a beam of light would require roughly 100,000 years to travel from one side of it to the other. But this also means that a galaxy is so large that, even if it were travelling at the speed of light, it would require 100,000 years just to vacate the space it currently occupies. See the picture below? That is a “magical real-time animation” of a galaxy moving to the right at the speed of light. Truly! Just watch the screen for a few hundred thousand years, and you will see the galaxy move right out of the picture. And you only have to watch for a few thousand years before you might maybe notice some change. Galaxies don’t actually move at the speed of light, so the bottom line is this: we do not actually see galaxies move.

Magic real-time animation of a galaxy moving to the right at the speed of light. Keep watching. By the year 7018 maybe you will notice some change.

Magic real-time animation of a galaxy moving to the right at the speed of light. Keep watching. By the year 7018 maybe you will notice some change.

Two galaxies colliding. This is truly a “slow-motion train wreck”—it will take a very, very long time before we see any change in this picture.

Two galaxies colliding. This is truly a “slow-motion train wreck”—it will take a very, very long time before we see any change in this picture.

Then what about all the stuff discussed in the last post? What about Edwin Hubble’s discovery in the late 1920’s that those galaxies that are more distant are moving away from us faster? What about the Hubble Plot?

Henrietta Leavitt (left) and Edwin Hubble (right)

Henrietta Leavitt (left) and Edwin Hubble (right)

Hubble made his discovery because Henrietta Leavitt figured out how to measure vast distances in space using certain kinds of stars as standards of measurement. A decade or so prior to Hubble, Leavitt discovered that the brightnesses of certain stars (stars with a certain peculiar pattern of fluctuations in light output) could be predicted, and then the predicted brightness could be compared to the observed brightness to estimate distance (the dimmer the star appeared vs. what was predicted, the farther away the star must be). Leavitt achieved what was arguably one of the biggest breakthroughs in the history of astronomy—and Hubble used Leavitt’s stars to measure the distance to galaxies, and without Leavitt’s stars he would have not made his discovery.

So if Hubble used Leavitt’s stars to measure the distance to galaxies, how did he measure movement of the galaxies? Obviously he could not see them moving. He measured their movement using the “Red Shift”—a reddening of the light emitted by each galaxy, caused by the Doppler Effect. The Doppler Effect is the same effect used in Doppler radar used by police to clock the speeds of cars on a highway. More Red Shift means more movement away.

So here is the key point: Hubble did not actually measure galaxy distances and galaxy movements. He measured brightnesses (of Leavitt stars in the galaxies) and Red Shifts (of galaxy light). From these, he used Leavitt’s method and the Doppler Effect to calculate distance and movement. Astronomers since Hubble have accepted all this.

But what if Leavitt’s method has problems? Or, what if the Red Shifts are caused by something other than galactic movement? Hubble himself would eventually come to believe that the Red Shifts are not caused by movement, and that the universe is not expanding.

Fr. Georges LeMaitre

Fr. Georges Lemaître

You see, around the same time that Hubble was doing his work, Fr. Georges Lemaître, a physicist and a priest, used Albert Einstein’s theory of relativity to calculate that the universe must be expanding—and that at one time the universe had been much smaller than it now is, and that in fact Einstein’s theory implied that the universe and even time itself all began on a “day without yesterday.” This was the Big Bang theory, and within the scientific community there were those who considered this priest’s theory to be nothing more than an effort to use science to bolster religious ideas—a new spin on the story of Creation from the first chapter of Genesis. (The usual scientific view at that time was that the universe is eternal and unchanging, and thus with no beginning.) Certain figures in the scientific establishment of the Soviet Union in particular dismissed Lemaître’s theory of a universe with a beginning as being just religion in disguise (more on that in the next post).

Edwin Hubble also did not care for the idea of a beginning to the universe. Whereas in the 1920’s Hubble had announced that he had found that the more distant galaxies were moving away from the Milky Way faster, in 1942 he wrote an article entitled “The Problem of the Expanding Universe”* in which he argued that the Doppler effect measurements of velocity that he had given earlier were probably erroneous, and that the changes in light from distant galaxies that he had earlier interpreted as Doppler Effect were instead due to some unknown phenomenon. Hubble wrote:

Red shifts are due either to recession of the nebulae [i.e. galaxies] or to some hitherto unrecognized principle operating in internebular space. The latter interpretation leads to the simple conception of a sensibly infinite homogeneous universe of which the observable region is an insignificant fraction. The alternative interpretation of red shifts as velocity shifts leads to a particular type of an expanding universe which is disconcertingly young, small and dense.

Hubble went on to argue that the evidence did not favor the interpretation of red shifts as being due to the velocities of galaxies, and concluded—

...on the basis of the evidence now available, a choice seems to be presented, as once before in the days of Copernicus, between a small, finite universe, and a sensibly infinite universe plus a new principle of nature. And, as before, the choice may be determined by the attribute of simplicity.

Astronomers today do not agree with Hubble on this. For many reasons, they overwhelmingly accept the idea that the Red Shifts do indicate motion, and that the universe is indeed expanding, and that Fr. Lemaître’s Big Bang theory is valid. But it is not impossible that Hubble could be right. At some point in the future, we could find out that something else causes the Red Shift. That would not be good news for the Big Bang theory, and it would really stir things in science generally. I would not bet on that happening, but if you read my recent post on Kepler and giant stars, you know that sometimes we scientists can be smart and can do things right and get the measurements right, but still come to the wrong conclusions because we do not understand what we are measuring. But right now, to the best of our knowledge, the galaxies are moving away from us and, “The universe is expanding.”

 

*Science, Volume 95 (February 27, 1942), 212-215; quotes from pages 214 and 215.

 

 

Go Observe – The Perseids and a comet

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The image is a screen shot from Stellarium. In it are the constellations Perseus and Cassiopeia . Along with the radiant of the Perseid Meteor Shower plus the position of comet 21P/Giacobini-Zinner

The image is a screen shot from Stellarium. In it are the constellations Perseus and Cassiopeia . Along with the radiant of the Perseids plus the position of comet 21P/Giacobini-Zinner

The Perseid Meteor Shower 2018 Facts

The Perseid Meteor Shower peaks on the nights of August 11th /12th and 12th / 13th  2017 but any clear evening up to and a few nights after should produce some meteors. Look to the NE after midnight, look under the big W of Cassiopeia , above Perseus. The radiant of the meteor shower is in that area, however keep an eye on a much wider area for Perseids.  Earth will pass through the path of Comet Swift-Tuttle from July 17 to Aug 24. Our planet will pass through dust and particles left behind by the comet. Most of these comet particles are only the size of a grain of sand. They hit our atmosphere at approx 59 km per second and burn up.   This year the moon will not interfere with the darkness of the sky as it will be a thin crescent setting before midnight.

What do you need to see the Perseids ?

It's the best meteor shower of the year, because it is mostly warm and being outside is comfy. Get yourself extra comfy by setting up a beach chair with a good view to the NE. A few snacks, maybe a blanket and that is it. All that is required is a clear night and being attentive to the sky. Some meteors are only fractions of seconds long, some seem like a minute. Some appear to have smoke coming out of them and some splutter across the sky.

Meteor Colours

As a tiny meteor enters the Earth’s atmosphere heat and light energy is created. A meteor’s composition ignites and interacts with Earth's atmosphere and its demise produces different colours. Meteors made of sodium produce orange/yellow light, iron will produce yellow, magnesium creates bluish/green, calcium makes violet and silicate meteors produce fiery red colours.

Other interesting objects to notice

At 22:30 Jupiter will be heading down in the South West, Saturn will shine in the South and Mars will look like a red emergency beacon towards the South East. ( Viewing from Ireland)    Within the constellation Cassiopeia you may find a comet ! 21P /Giacobini- Zinner has brightened. With a bit of effort you and your telescope might be lucky enough to find it in a dark sky. This is a small comet but worth a look !!!

Read my previous blogs about the Perseids 21 Precious Perseids  

Get ready the Perseids are Coming

Watch a video about What's Up for August 2018 

Astronomy Software for you 

Follow comets here

Please Welcome our new Blogger: Chris Olsen

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Chris Olsen

Chris Olsen has a degree in history, and is a student of 19th-century photography and science. Chris does daguerreotypes and wet plate collodion, which are the two first photographic processes that were commercially successful.

Chris works as an operator at Fermi National Accelerator Lab; this offers him the very special privilege of taking his camera equipment into the accelerator complex and using this 150-year-old process to take pictures of it. Chris also does backstage concert photography and takes pictures of Civil War reenactors. Chris uses his own 19th-century equipment, and gives these photographs to the Civil War reenactors as gifts.

Chris will be writing a series about 19th century solar observation, and recreating the instruments used during that period. Chris has started researching the English scientist and astronomer Norman Lockyer; during the next total solar eclipse, Chris hopes to "discover" the element helium using the spectrometer he built.

 

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Across the Universe: Off The Beach

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This entry is part 21 of 170 in the series Across the Universe

This column first appeared in The Tablet in August 2004. It ran here at the Catholic Astronomer in August, 2015.

Scientists have a reputation of being nerds with no social skills, and yet like actors and athletes we spend most of our careers working in teams. It’s a rare scientific paper that has only one author.

This social aspect of science is especially clear at the annual meetings of scientific organizations. Obviously meetings are important for practical reasons. If you don’t tell anyone what you’ve done, you might as well not have done it. If you don’t know what others are doing, you can’t pitch in to help the field along. And if we didn’t have meeting deadlines to meet, we’d never get the work done!

But meetings are also attractive precisely because they are social events. The first week of August [2004] found me in a resort hotel on the beach of Rio de Janeiro with two hundred other meteorite specialists, listening to a hundred talks and joining in countless rump sessions over dinner, or beers, sharing with each other our excitement about topics at the limits of our imagination...

Now-extinct radioactive isotopes, made billions of years ago in supernovae, have left traces that let us pinpoint the age of the solar system to within a few hundred thousand years.

Asteroids hit South America, perhaps as recently as a mere few thousand years ago with more destructive power than the combined energy of all the nuclear bombs ever made, but their craters are now barely visible under the lush vegetation.

The abundance of the rare trace element Osmium in the Earth may put limits on how many comets hit our planet over the past four billion years...

A group from a more recent MetSoc meeting, this one in Canada in 2013

You can trace a social history of the our science in the accents of these conversations. A great many of the biggest names in the field speak with accents from the British Isles, but virtually all of them over 50 have spent their careers in the United States. Fortunately the next generation, after working abroad, have found jobs closer to home; and indeed the accents of younger scientists whose name tags say “Germany” or “France” (or even “Vatican”) are often distinctly North American. The youngest participants have an even wilder variety of accents: Czech and Japanese and, at this meeting, Brazilian.

Along with this mixture of accents, there’s come a blending of the old national stereotypes about the way that science is done. It’s not only Germans who are ultra-precise; and some American teams can match the Japanese when it comes to group-think. Likewise, it’s no longer just the British who champion eccentric theories, so delightfully prevalent in my field.

For instance, nobody understands those little droplets of once-molten rock found only in meteorites, called chondrules; with no consensus, every theory for how they were made looks odd.

Chondrules from the Vatican meteorite collection

Chondrules from the Vatican meteorite collection

 

“They condensed like raindrops in a high pressure gas cloud that formed the planets!”

“They were droplets splashed out when two molten asteroids collided!” “

They were balls of dust flash-melted by powerful x-rays emitted by the young Sun!”

There’s a danger in proposing these odd theories. In a business where your reputation is your biggest asset, no one wants to be thought a crank. But the social dynamics in our field allow us the occasional crackpot idea, so long as we’ve paid our dues to the community by also doing the solid, unexciting work of data taking and sample curation that keeps the field going.

We need both. We need the plodding grind who spends a lifetime adding a decimal place of precision to the measurement of oxygen isotopes, and the dreamer who can spin a theory of swirling gases and exploding stars to explain the slightest anomaly in those data. The dreamers’ outrageous ideas often inspire the grinds to take the data that may prove the dream was baseless, but in the process open up unexpected puzzles and dazzling possibilities.

There’s no reason why dreamer and grind can’t both be found in the same person. More often, they’re lucky just to be found in the same lab. Of course, it’s the dreamer who gets named in the Sunday Supplements; fortunately, it’s usually only the dreamer who would want to be seen there.

In other words, the scientific community is no different from any other collection of human beings. Movies and sports teams too need both stars and supporting players, even as sometimes the star of one show is the bit-player of the next. The variety refreshes.

Churches are no different. Churches need saints; oddly enough, they also need sinners. (Jesus certainly spent most of his time recruiting among them.) Though we may be shamed by our sins, we should never be ashamed to be sinners; the more unworthy we are of God’s love, the more proud we can be to have received it. In the same way, when we dare propose the occasional crazy idea, we also learn to appreciate the esteem with which our colleagues hold us in spite of our outrageousness.

The joy of this field is its mixing of careful data and unfettered dreaming. And in Rio, I had the time of my life... so much so that, I admit, I never did get to the beach. Scientists may be a social people, but I never denied I was a nerd.

Update 2018: I just returned from the Meteoritical Society's annual meeting, which this year was held in Moscow. Many of the same questions are still being discussed!

Sacred Space Giving Program

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Support The Catholic Astronomer Blog

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Image Credits:
Messier 45 - The Pleiades Star Cluster. Image via Project Nightflight.
Messier 13 - The Great Cluster in Hercules. Image acquisition by Jim Misti, image processing by Robert Gendler.
Messier 31 - The Andromeda Galaxy. Credit: NASA, ESA, Digitized Sky Survey 2 (Acknowledgement: Davide De Martin)

To Live Is To Change, And To Be A Catholic Priest Is To Change Addresses Often (Part 2)

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First of all, my deep apologies for my absence these past few weeks on The Catholic Astronomer. One of the occupational hazards of parish priests is assignment changes. As of July 5, 2018, I started a new assignment at St. Olaf Parish in Eau Claire, Wisconsin. It has been a smooth transition to a city I know well and a parish that is home to some of my best students from my High School teaching days. Now, I'm celebrating their weddings and doing the baptisms of their children. I'm feeling older than I should!

Now that the boxes are almost unpacked and a new sense of "normal" is setting in, I'll be getting back to my weekly blurbs for you. A fun event that is on my radar screen is the Chippewa Valley Astronomical Society's Star Fest from August 17-19, 2018. It's an annual event that brings local amateur astronomers together to enjoy a weekend of star gazing and education at the Hobbs Observatory, just outside of Eau Claire at the Beaver Creek Nature Reserve. I will be a presenter at Star Fest this year, talking about the history of the Vatican Observatory and the research that the Vatican Observatory does! In that spirit, below are a couple videos that nicely summarize the themes I will explore in my presentation.

Question: What are the summer star party events in your area? How can you explore your love of astronomy as part of your summer fun? Pray with and explore these questions. I invite you to post star party events in your area in the comment section below. May all of us make gazing at the heavens a part of our summer relaxation!

Image from the Chippewa Valley Astronomical Society.

In the Sky This Week – July 31, 2018

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This entry is part 54 of 56 in the series In the Sky This Week

Mars opposition happened last week with the Earth overtaking Mars in its orbit; the Earth will now pull ahead of Mars as the distance between the two planets increases over the next several months. Mars will slowly dim, and shrink in size in telescopes, but should still be a good observing target for several weeks.

Southern sky July 31 2018

Mars and Saturn are bright in the early morning sky to the south on July 31, 2018. The Moon also be visible in the early morning sky all week. Credit: Stellarium / Bob Trembley.

Jupiter is in the southwestern sky at dusk and sets around 11:30 PM; Saturn is an excellent observing target all night long in the southern sky.

Planets in the southern sky

Jupiter and Saturn in the southern sky at 10:00 PM, July 31 2018. Credit: Stellarium / Bob Trembley.

Jupiter continues a slow crawl towards the Venus in the west; Venus appears a bit lower in the western sky each evening.

Southwestern sky at dusk, July 31, 2018

Venus and Jupiter are in the southwestern sky at dusk, July 31, 2018. Credit: Stellarium / Bob Trembley.

Southern Hemisphere:

From Montevideo, Uruguay, Venus is high in the west-northwestern sky at 5:00 PM on July 31 2018, and as you'll note, it's dark. Jupiter is VERY high in the northwestern sky.

Northwest sky from Montevideo, Uruguay July 31 2018 5:00 PM

From Montevideo, Uruguay, Venus is high in the west-northwestern sky at 5:00 PM July 31 2018. Jupiter appears in the northwestern sky, and is much higher than in the northern hemisphere.

Mars is high in the eastern sky from Montevideo at 5:00 PM on July 31 2018, Saturn appearing much higher and opposite side from Mars as it appears in the northern hemisphere.

Eastern sky from Montevideo, Uruguay July 31 2018 5:00 PM

From Montevideo, Uruguay, Mars and Saturn are high in the eastern sky at 5:00 PM July 31 2018. Saturn appears much higher in the sky, and is on the opposite side from Mars than in the northern hemisphere.

The Moon

The Moon is a waning gibbous, rising after dark and setting in the mid-morning. The Moon will be at third quarter on August 4th, setting around 12:30 PM. After the 4th the Moon will be a waning crescent, visible in the southeastern sky before sunrise.

Moon

The Moon from July 31-Aug. 6, 2018. Visualizations by Ernie Wright

Observing Target: Mars

Mars is just about as close to Earth as it gets - I'm seeing several posts saying that Mars is closer to Earth than it's been in 15 years. Even though Mars is experiencing a global dust storm, telescopes across the globe will be pointed at Mars, and photos will be taken. Even the Hubble Space Telescope is gazing at Mars:

The Sun

The Sun as been spot-free for 9 days - an active region with some coronal loops activity is rotating into view. There is a HUGE coronal hole at the north pole, and the hole at the south pole appears to have diminished quite a bit. There are a couple small equatorial holes within a boiling region where it appears holes are trying to form and connect.

The solar wind speed is 317.1 km/sec, with a density of 8.7 protons/cm3.

SpaceWeather.com says: "The sun has been without sunspots for 33 of the past 34 days. To find a similar stretch of blank suns, you have to go back to 2009 when the sun was experiencing the deepest solar minimum in a century. Solar minimum has returned, bringing extra cosmic rays, long-lasting holes in the sun's atmosphere, and strangely pink auroras."

Some nice-sized prominence activity on the Sun over the last couple days; that active region I mentioned above appears as the bright orange area below.

You can view the Sun in near real-time, in multiple frequencies here: SDO-The Sun Now.
You can create your own time-lapse movies of the Sun here: AIA/HMI Browse Data.
You can browse all the SDO images of the Sun from 2010 to the present here: Browse SDO archive.

Asteroids

Upcoming Earth-asteroid encounters:

Asteroid
Date(UT)
Miss Distance
Velocity (km/s)
Diameter (m)
2018 NR1
2018-Jul-27
17.1 LD
5.1
35
2018 OZ
2018-Aug-06
7 LD
9.6
34
2018 LQ2
2018-Aug-27
9.4 LD
1.5
39
2016 GK135
2018-Aug-28
16.8 LD
2.8
9
2016 NF23
2018-Aug-29
13.3 LD
9
93
1998 SD9
2018-Aug-29
4.2 LD
10.7
51
2018 DE1
2018-Aug-30
15.2 LD
6.5
28
2001 RQ17
2018-Sep-02
19.3 LD
8.3
107
2015 FP118
2018-Sep-03
12.3 LD
9.8
490
2017 SL16
2018-Sep-20
8.5 LD
6.4
25

Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. Table from SpaceWeather.com

Near-Earth objects (NEOs) discovered this month: 82, this year: 972, all time: 18523.
Potentially hazardous asteroids: 1912 (as of July 31, 2018)
Minor Planets discovered: 779,736 (as of July 31, 2018)

Fireballs

On July 30, 2018, the NASA All Sky Fireball Network reported 21 fireballs.

Fireball Orbits

In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. Source: Spaceweather.com

The Solar System

This is the position of the planets and a couple spacecraft in the solar system:

Inner Solar System

Position of the planets in the inner solar system - a few days after Mars opposition - July 31, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.

Exoplanets

Confirmed Exoplanets: 3,774 (7/19/2018)
Multi-Planet Systems: 625 (7/19/2018 )
Kepler Candidate Exoplanets: 4,496 (8/31/2017)
TESS Candidate Exoplanets: 0
Data from the NASA Exoplanet Archive

Apps used for this post:

Stellarium: a free open source planetarium app for PC/MAC/Linux. It's a great tool for planning observing sessions.
NASA Eyes on the Solar System: an immersive 3D solar system and space mission simulator - free for the PC /MAC. I maintain the unofficial NASA Eyes Facebook page.

NASA 60th Anniversary

2018 is NASA's 60th anniversary!

Asteroids Named for Jesuits

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Asteroids Named After Jesuits - orbit diagram

These ten asteroids were all named after Jesuits.  I should note that the list is not exhaustive; there may be other asteroids that are named for Jesuits, but this is what I came up with after a couple hours' search of the IAU minor planet center database.

St. Ignatius Loyola

Portrait by Peter Paul Rubens. (Public Domain)

 

3562 Ignatius

  • e 0.1546
  • a 2.3387 AU
  • i 5.7256 deg
  • P 1306.358 days

St. Ignatius Loyola (1491-1556) was the founder of the Jesuit order. The name of the asteroid was given to Ignatius in 1991 in honor of the 500th anniversary of his birth. (Ref: Minor Planet Circular 17028)

 

 

 

 

Maximilian Hell

Portrait artist unknown.       (Public Domain)

 

3727 Maxhell

  • e 0.1500
  • a 3.318 AU
  • i 5.377 deg
  • P 2207.577 days

(Minor Planet Circular 26424): Named in memory of Maximilian Hell (1720-1792), famous for his determination of the solar parallax from his observations of the transit of Venus in 1769. Appointed director of the imperial observatory in Vienna in 1755, he prepared and published an important series of astronomical ephemerides. Name suggested by astronomers at the Astronomical Institute at Tatranská Lomnica. 

I add: Maximilian Hell SJ was a Hungarian Jesuit. He was alive at the time of the suppression of the Jesuit order in Austria and Hungary in 1782.

 

 

Br. Guy Consolmagno SJ

Photo: Vatican Observatory

 

4597 Consolmagno

  • e 0.11945
  • a 2.609 AU
  • i 4.868 deg
  • P 1539.18 days

(Minor Planet Circular 41381): Through experimental petrology, Guy Consolmagno (b. 1952) studied the origins of eucritic meteorites. As the curator of the Vatican meteorite collection, Guy's more recent efforts have focused on determining the densities and porosities of meteorites and making comparisons with the densities of minor planets.

I add: Br. Guy Consolmagno SJ is a member of the Maryland province of the Society of Jesus. In 2015, he became director of the Vatican Observatory, a post that he continues to hold today.

 

 

Fr. Angelo Secchi SJ

(Public Domain)

 

4705 Secchi

  • e 0.1278
  • a 2.329 AU
  • i 8.637 deg
  • P 1298.64 days

(Minor Planet Circular 20160): Named in memory of Angelo Secchi (1818-1878), Italian astronomer, director of the observatory of the Collegio Romano in Rome from 1848 to 1878. Famous for his work on stellar spectroscopy, he made the first spectroscopic survey of the heavens, and his classification scheme divided the spectra of the stars into four groups. Secchi also made an extensive study of solar phenomena and was a co-founder of the Societa degli Spettroscopisti Italiani, now the Societa Astronomica Italiana.

I add: Fr. Angelo Secchi SJ was a Jesuit who was ordained a priest in 1847.

 

Br. Bob Macke

 

11266 Macke 

  • e 0.244
  • a 3.2356 AU
  • i 1.863 deg
  • P 2125.84 days

(Minor Planet Circular 103977): Robert J. Macke SJ (b. 1974) is a research scientist and meteorite curator at the Vatican Observatory, whose fundamental contributions include studying the relationship between shock state and porosity in carbonaceous chondrites.

I add: Oh, hey, that's me!

 

Roger Boscovich

Portrait by Robert Edge Pine, London, 1760. (Public Domain)

 

14361 Boscovich

  • e 0.09627
  • a 2.582 AU
  • i 13.243 deg
  • P 1515.67 days

(Minor Planet Circular 41940): Ruggiero Giuseppe Boscovich (1711-1787), Jesuit professor of mathematics and philosophy at Rome and Pavia, was for some years in Paris and later in Milan, where he founded the Brera Astronomical Observatory. He wrote on the determination of orbits of comets, mathematics and optics.

 

 

 

 

Fr. George Coyne SJ

Photo: Vatican Observatory

 

14429 Coyne

  • e 0.3008
  • a 2.441 AU
  • i 21.3956 deg
  • P 1393.06 days

(Minor Planet Circular 41572): George Coyne (b. 1933), S.J., has been an astronomer at the Vatican Observatory since 1969 and its director since 1978. He has helped with the completion of the large Vatican telescope on Mt. Graham, Arizona. His polarimetric studies have centered on cataclysmic variables, among other subjects. 

I add: Fr. Coyne stepped down as director of the Vatican Observatory in 2006, and is currently the McDevitt Distinguished Chair in Religious Philosophy at LeMoyne College in Syracuse NY.

 

 

Christopher Clavius

Engraving by Francesco Villamena (Public Domain)

 

20237 Clavius

  • e 0.06685
  • a 2.1496 AU
  • i 3.661 deg
  • P 1151.127 days

(Minor Planet Circular 110623): Christopher Clavius (1538-1612) was a German mathematician and astronomer. He figured out where to place the leap years in the Gregorian calendar. Pope Gregory XII revised the Julian calendar with the assistance of Clavius.

I add: Fr. Clavius was a German Jesuit who entered the order in 1555, and was one of the most celebrated mathematicians of his day.  Fr. Matteo Ricci SJ, who used his knowledge of mathematics and astronomy to gain access to the Chinese court, was trained by Clavius.

 

 

Fr. Jean-Baptiste Kikwaya Eluo SJ

Photo: Vatican Observatory

23443 Kikwaya

  • e 0.12417
  • a 2.5668 AU
  • i 14.901 deg
  • P 1502.02 days

(Minor Planet Circular 89082): Jean Baptiste Kikwaya Eluo (b. 1965) is a native of the Democratic Republic of Congo and Staff Astronomer at the Vatican Observatory. Using optical meteor measurements, he estimates the bulk densities of smaller meteoroids through numerical ablation models. 

I add: Fr. Jean-Baptiste Kikwaya SJ also dedicates much of his scientific study to near-earth asteroids.

 

 

Fr. Richard Boyle SJ

Photo: Vatican Observatory

302849 Richardboyle

  • e 0.1144
  • a 3.158 AU
  • i 25.606 deg
  • P 2049.93 days

(Minor Planet Circular 98715): Richard Boyle (b. 1943) is an astronomer at the Vatican Observatory. His work has specialized in high-precision photometry of stars and stellar clusters, often using Vilnius system filters. His work has application ranging from asteroseismology to the discoveries of asteroids with the Vatican Advanced Technology Telescope. 

 

Please Welcome our new Blogger: Brother Bob Macke SJ

The Catholic Astronomer avatarPosted on by

Br. Bob Macke

Br. Bob Macke joined the Vatican Observatory in July 2013, where he studies meteorite physical properties in the observatory’s meteorite laboratory. In August 2014, Br. Bob became the curator of the Vatican collection of 1200 meteorite specimens.

Br. Bob is a member of the U.S. Central and Southern Province of the Society of Jesus. He was born in Fort Worth, Texas in 1974. After studying physics at the Massachusetts Institute of Technology (MIT) and Washington University in St. Louis, he taught astronomy for a few years at Bowling Green State University (Bowling Green, Ohio) before entering the Society of Jesus in 2001.

As a Jesuit, he studied philosophy at St. Louis University. He then taught physics, astronomy, and mathematics at Rockhurst University (Kansas City, Missouri) for one year, and then began a doctoral program studying meteorite physical properties at University of Central Florida. His dissertation, Survey of Meteorite Physical Properties: Density, Porosity and Magnetic Susceptibility, detailed measurements on more than 1200 individual meteorite specimens from major collections throughout the United States and Europe. Between 2011 and 2013 he studied theology at Boston College School of Theology and Ministry, during which time he also constructed a new ideal-gas pycnometer for measuring meteorite densities.

Br. Bob studies the physical properties of meteorites, including density, porosity, magnetic susceptibility, and more recently, thermal properties. His research has been conducted on most of the major meteorite collections in the United States and Europe. In addition, Br. Bob is involved in a study concerned with interpreting gravimetric data from the surface of the Moon and Mars. This requires measuring the density and porosity of lunar and Martian materials including not only meteorites but also lunar samples brought back to earth by the Apollo space missions of the 1960’s and 1970’s. To date, he has measured about 60 individual Apollo moon rocks from all 6 successful missions and all representative lithologies.

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Br. Bob will write a series on Religious Scientists of the Catholic Church, and post an occasional tidbit relevant to the activities or history of the Vatican Observatory. We welcome Br. Bob to our team of bloggers, and look forward to his posts!

NASA Space Place: The Best Meteor Shower of the Year

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The Best Meteor Shower of the Year NASA Space Place Logo

By Jane Houston Jones and Jessica Stoller-Conrad

If you’re a fan of meteor showers, August is going to be an exciting month! The Perseid meteor shower is the best of the year, and in 2018, the peak viewing time for the shower is on a dark, moonless night—perfect for spotting meteors.

The best time to look for meteors during this year’s Perseid shower is at the peak, from 4 p.m. EDT on Aug. 12 until 4 a.m. EDT on the Aug. 13. Because the new Moon falls on the peak night, the days before and after the peak will also provide very dark skies for viewing meteors. On the days surrounding the peak, the best time to view the showers is from a few hours after twilight until dawn.

Meteors come from leftover comet particles and bits from broken asteroids. When comets come around the Sun, they leave a dusty trail behind them. Every year Earth passes through these debris trails, which allows the bits to collide with our atmosphere and disintegrate to create fiery and colorful streaks in the sky—called meteors.

The comet that creates the Perseid meteor shower—a comet called Swift-Tuttle—has a very wide trail of cometary dust. It’s so wide that it takes Earth more than three weeks to plow all the way through. Because of this wide trail, the Perseids have a longer peak viewing window than many other meteor showers throughout the year.

In fact, this year you should be able to see some meteors from July 17 to Aug. 24. The rates of meteors will increase during the weeks before Aug. 12 and decrease after Aug. 13. Observers should be able to see between 60 and 70 meteors per hour at the shower’s peak.

The Perseids appear to radiate from the constellation Perseus, which is where we get the name for this shower. Perseus is visible in the northern sky soon after sunset this time of year. Observers in mid-northern latitudes will have the best views.

However, you don’t have to look directly at the constellation Perseus to see meteors. You can look anywhere you want to; 90 degrees left or right of Perseus, or even directly overhead, are all good choices.

Perseids Radiant

The Perseid meteor showers appear to radiate from the constellation Perseus. Perseus is visible in the northern sky soon after sunset this time of year. Credit: NASA/JPL-Caltech

While you’re watching the sky for meteors this month, you’ll also see a parade of the planets Venus, Mars, Jupiter and Saturn—and the Milky Way also continues to grace the evening sky. In next month’s article, we’ll take a late summer stroll through the Milky Way. No telescope or binoculars required!

Catch up on all of NASA’s current—and future—missions at www.nasa.gov

This article is distributed by NASA Space Place.

With articles, activities and games NASA Space Place encourages everyone to get excited about science and technology. Visit spaceplace.nasa.gov to explore space and Earth science!

Imagine an Expanding Universe

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“The universe is expanding.”——Since you are reading a science blog such as The Catholic Astronomer, you probably are familiar with that statement. But do you know why astronomers say that the universe is expanding? What is the basis for that statement?

To address that question, let’s consider this: what would an expanding universe look like?

This is going to take some imagination. Let us imagine a universe. The diagram below will be our universe. It contains galaxies (the little colored ovals), but its size and shape is undefined. The galaxies extend out beyond what is seen below, but how much beyond we do not know. Furthermore, the galaxies may extend out farther to the right than to the left, or farther down than up. All we really know is that here is our universe, and it contains galaxies.

Our imagined universe of colorful galaxies.

Our imagined universe of colorful galaxies.

Now, let us expand this universe. We will expand it uniformly—that is, equally in all directions. We will color the expanded universe grey. Note that all the galaxies are the same in both the original and the expanded versions of our imaginary universe. If you wish, break out a ruler and measure; you will see that our expanded universe is indeed larger in all directions.

Our imagined universe, expanded.

Our imagined universe, expanded.

Side-by-side view of our imagined universe (left), and expanded (right). The arrow is of fixed length, to help show the expansion.

Side-by-side view of our imagined universe (left), and expanded (right). The arrow is of fixed length, to help show the expansion.

Now, let us focus on one particular galaxy. And, let us suppose that any observer living in that galaxy can only see so far out into the universe. Since our observer can only see so far, and since the galaxies extend out indefinitely, our observer will see himself or herself as being at the center of all that can be seen. Like this—

Focusing on one galaxy.

Focusing on one galaxy.

Now let’s do this same thing for the same galaxy, but with the universe expanded—

Focusing on one galaxy—expanded universe.

Focusing on one galaxy—expanded universe.

Finally, let’s overlay these two on top of each other, so that we see both from the point of view of the observer in our focus galaxy—

Focusing on one galaxy—overlay of original and expanded universe.

Focusing on one galaxy—overlay of original and expanded universe.

Note how, in the expansion of the universe, our focus galaxy appears to be at the center of the expansion. That makes sense, if you think about it: when we enlarged the universe, we made all the distances between galaxies bigger. So, the distance from our focus galaxy to each and every other galaxy in our imaginary universe is larger. So, each and every other galaxy is moved away from our focus galaxy. Note also that the farther galaxies are moved more than the nearer ones. A “zoomed in” picture shows this more clearly—

A more distant galaxy (brown arrow) is moved by the expansion more than a nearby galaxy (purple arrow).

A more distant galaxy (brown arrow) is moved by the expansion more than a nearby galaxy (purple arrow).

If we enlarge the entire overlay picture (you can click on any one of these images to enlarge it) and use a ruler to crudely measure both the distance from our central focus galaxy to every other galaxy, and the amount each galaxy moves away from our central focus galaxy, we find that this trend of farther galaxies moving more than nearer ones holds for all the galaxies, and that the pattern of increase is more or less linear—

A plot of movement vs. distance, made by making measurements from the overlay picture using a ruler. Note the linear “up and to the right” trend of more distant galaxies moving more.

A plot of movement vs. distance, made by making measurements from the overlay picture using a ruler. Note the linear “up and to the right” trend of more distant galaxies moving more.

Try this with a ruler for yourself—you will find you get the same results.

Now, let’s try this out on another galaxy. This time let’s chose the green galaxy that is just to the left of our previous focus galaxy—

Focusing on a second galaxy.

Focusing on a second galaxy.

Here is the overlay for this second galaxy—

Focusing on the second galaxy—overlay of original and expanded universe.

Focusing on the second galaxy—overlay of original and expanded universe.

As you can see, any observer who might be in the second galaxy would see exactly the same pattern as the observer in the first galaxy sees. Both observers see their galaxies as being at the center of an expanding universe, and both see that farther galaxies are moving away from them more, and that the trend is linear.

And this is exactly what we see in our universe. The first person to see it was Edwin Hubble in the late 1920’s. He measured the distances to different galaxies and the movement of those galaxies, and then made a graph of galaxy distance vs. galaxy movement. His graph showed a linear pattern of farther galaxies having more movement away from us. Indeed, graphs like this are now called “Hubble Plots”. Below is Hubble’s original graph, along with a more modern Hubble Plot.

Left—Hubble’s original plot. Right—a modern “Hubble Plot” using data from 108 galaxies. Note how both plots show that same linear “up and to the right” trend, where the more distant a galaxy is from us, the more rapidly it is moving away from us.

Left—Hubble’s original plot. Right—a modern “Hubble Plot” using data from 108 galaxies. Note how both plots show that same linear “up and to the right” trend, where the more distant a galaxy is from us, the more rapidly it is moving away from us.

Thus, our universe is behaving just like the expanding universe that we imagined above. This is why astronomers say “The universe is expanding.” The view from here, on our planet in our galaxy, is that we are at the center of this expansion. However, as we saw earlier, inhabitants of any other galaxy in the universe will see themselves at the center, too. (Who is really at the center, and whether a center even exists, is a matter for another day.)

It is important to keep in mind that this expansion only refers to the distances between galaxies. The distance between Venus and the sun, for example, is not getting bigger. The Earth is not getting bigger. Some moon orbiting some planet in some other star system is not getting bigger. Your hand is not getting bigger. When astronomers say “The universe is expanding”, they only mean the distances between galaxies is getting bigger.

However, there have been some astronomers who have not believed that the Hubble Plots are evidence for an expanding universe. One such astronomer was, interestingly enough, Edwin Hubble.

And that is the subject of my post for next week.