IAU Adds Lemaître’s Name to Hubble Law
This year marked my first opportunity to attend a general assembly of the International Astronomical Union. It was an exciting two weeks in which scientists from all branches of astronomy and space physics gathered in beautiful Vienna, Austria to discuss their research and to do the work of the IAU. Walking around the meeting venue, one could see astronomers of all stripes, from all over the world, and occasionally one could catch a glimpse of one of the “Big Names” in astronomy wandering about, usually in heated discussion with others about some important topic or other.
What makes the IAU different from other scientific meetings is that it serves as the governing body for those aspects of astronomy that require universal agreement, such as the naming of stars and asteroids or of features on planets and moons. It was the IAU that famously voted in 2006 to change the definition of a planet, which resulted in the “demotion” of Pluto to the status of dwarf planet. I was particularly excited to attend the business meetings of the IAU in order to participate in this process. I was not one of the national representatives—for the Vatican, that honor belonged to Fr. Paul Gabor, S.J., Fr. Chris Corbally, S.J., and Fr. Richard Boyle, S.J., all of whom are members of the Vatican Observatory—but the general membership was permitted to vote on all scientific matters. For the most part, these consisted of nothing important or controversial; most passed unanimously and I cannot even remember what they were.
One issue in particular created quite a bit of excitement and discussion, and ultimately they decided that the issue was too important to limit the vote to the members who were present at the assembly, but rather they extended a period of online voting for the entire membership of the IAU. This resolution regarded the renaming of the Hubble Law to the Hubble-Lemaître Law, thus recognizing Lemaître’s contributions to our understanding of the expansion of the universe as a result of the Big Bang.
Msgr. Georges Lemaître (left) with Albert Einstein. (Photo taken at Caltech in 1933)
Msgr. Georges Lemaître was a Catholic priest of the archdiocese of Leuven, Belgium. He was also an astrophysicist and professor of physics at the Catholic University of Leuven, and a contemporary of Albert Einstein. At a time when many cosmologists insisted on a steady-state model of a static, non-expanding universe, Lemaître noted that the geometry of Einstein’s theory of general relativity was more consistent with an expanding universe, and his expanding-universe model was also consistent with the observed redshift of galaxies. Also, if the universe was expanding, he inferred that at some point in the past, the entire universe would have been condensed into an infinitely dense, infinitely hot point. He referred to this theory as the primordial atom, but his detractors—in particular Fred Hoyle—thought the theory smacked of theism (if there is a moment of creation, there must be a Creator), and blew it off with the dismissive name, “big bang.”
Lemaître published work on this topic in 1927. Hubble and Lemaître then exchanged information about their work at the third IAU assembly in 1928, and Hubble published his own work on the velocity-distance relation of galaxies in 1929. When in 1931 Lemaître published an English translation of his 1927 paper, he intentionally omitted the section on the effects of expansion on the recession of galaxies because he “did not find advisable to reprint the provisional discussion of radial galaxies… which could be replaced by a bibliography of ancient and new papers” [e.g. Hubble] “on the subject.”
The Fourth IAU General Assembly in 1932. Lemaître is marked with an arrow.
The voting period for the IAU resolution ended on Friday, October 26, 2018, and the results were just announced on Monday the 29th.With 78% of votes in favor, the resolution passed.
In addition to recognizing Lemaître’s obvious and valuable contributions to cosmology, the change of the name of the Hubble-Lemaître Law has another important implication for persons of faith. Astronomy textbooks will be adjusted to include this new name. Along with Gregor Mendel for biology, here is another religious scientist whose name will become recognizable to any high school or college student who takes a basic course in astronomy. In a culture that increasingly preaches a dichotomy between faith and science, it is important to have figures that we can hold up who exemplify the compatibility of the two. History is full of such examples, but most are hidden, forgotten, or actively ignored because they do not fit the narrative.
Lemaître had a profound respect for both faith and science, and recognized their respective roles and respective limitations. When Pope Pius XII wanted to proclaim the theory of the primordial atom as a scientific validation of the theology of Creation, Lemaître—with the help of Fr. Daniel O’Connel SJ, the director of the Vatican Observatory—talked him out of it, emphasizing the importance of allowing the science to proceed on its own without theological entanglements and vice versa.
Excerpt from the Vatican Observatory guest book for May of 1957, during the meeting on stellar populations. The arrows indicate the signatures of Georges Lemaître and Fred Hoyle. Other signatures are from recognizable figures in astronomy.
Lemaître is also a good personal example in contradiction to today's culture of extreme partisanship and its effect on our interpersonal relationships. He and Fred Hoyle held opposite and occasionally antagonistic positions both in their science and in their faiths; where Lemaître was a devout Catholic priest, Hoyle was an agnostic who leaned toward atheism; and while Lemaître was a proponent of Big Bang cosmology, Hoyle supported a steady state model and was an outspoken critic of the Big Bang. Nevertheless, they had respect for each other and in fact became friends. In 1957 the Vatican Observatory hosted a meeting on stellar populations in which the two both participated, and afterwards they took a driving vacation together throughout Europe. They show that it is possible to strongly disagree and yet remain friends.
For more about the IAU resolution, follow this link.
Solar Prominences and a Prominent Jesuit Astronomer
Fr. Angelo Secchi SJ (1818-1878)
Fr. Angelo Secchi, S.J. was the director of the observatory of the Pontifical Roman College from 1848 until his death in 1878. During that time, he made important contributions in many areas of astronomy and terrestrial physics, including stellar spectroscopy, terrestrial magnetism, oceanography, meteorology, geodesy and cartography, and more. He can rightly be considered a founder of astrophysics, as he was one of the first astronomers to attempt to study the physics of stars, using the new technique of stellar spectroscopy to classify and study about 4000 stars. In honor of Solar Week, this post will focus on his contributions to solar astronomy and solar physics, and in particular to one study among many: the study of solar prominences.
Secchi was interested in all aspects of solar physics. He took spectra of the solar atmosphere and the solar corona. He made many studies of sunspots and solar rotation. He even set up a terrestrial magnetism laboratory in his observatory facility atop the church of St. Ignatius in Rome, in order to study variations in the Earth’s magnetic field and its correlation to solar activity. He was also a pioneer in solar photography.
Before the 1860s, one of the outstanding questions in solar astronomy was the nature of solar prominences. Such objects had been observed around the disk of the Sun during eclipses, but it was still unknown what they were, or if they were even actually Solar phenomenon. It was thought that they might be a peculiar atmospheric phenomenon of the light passing through cloud layers or something. It would not be difficult to test this idea. All it would take would be to compare the prominences seen from two different parts of the Earth, close in time to each other. If prominences were an atmospheric phenomenon, then the light passing through two different parts of the atmosphere would produce two different sets of prominences. If they were a solar phenomenon, then they should match up.
This is easier said than done. It requires the use of astronomical photography, which was still in its infancy at that time. It also requires a solar eclipse to take place with a sufficiently long path that crosses over accessible lands where observations can take place at a distance of several hundred kilometers, preferably with clear weather. Fortunately, opportunities presented themselves in 1860 and in 1870.
On July 18, 1860, a total solar eclipse path crossed through the Iberian peninsula. Secchi stationed himself at a Carmelite monastery in Las Palmas, from which he could photograph the eclipse. The English astronomer Warren De la Rue also photographed the eclipse from Rivabellosa, about 500 km away from Secchi. By comparing the photographs from the two locations, Secchi found that the prominences matched up. This confirmed that they were truly features of the Sun, and not an illusion or atmospheric phenomenon. Secchi made similar observations during an eclipse over Sicily in December, 1870.
Etchings based on photographs of solar prominences taken from different locations during the eclipse of 1860, showing that they match up. (Note: small differences in are due to differences in timing and quality of photographs.) [From Le Soleil 2nd ed., 1875]
Secchi’s work on the Sun was published in 1870 in a large volume of about 1000 pages, written in French, entitled Le Soleil. This text was subsequently translated into German and Italian, and a second edition (this time in two volumes) was published in 1875. It is considered the most important treatise on the Sun for its day.
So why have you probably not heard of any of this? This is largely due to the astronomer Sir Norman Lockyer. He was the founder and first editor of the journal Nature. As an astronomer he studied solar physics, and his work on eclipse observations and solar spectroscopy put him in direct competition with Secchi. Because of this rivalry, he used his considerable influence among the English publishing houses to ensure that Secchi’s work was never published in English.
Today, the pair of space-born solar observatories known as STEREO each carry an instrument package named “Sun-Earth Connection Coronal and Heliospheric Investigation” (SECCHI) in his honor.
For more about Angelo Secchi, there is a short video on the Vatican Observatory Foundation YouTube channel:
A Saint, a Telescope, and a Man on the Moon
Pope St. Paul VI looking at the moon through the Vatican Observatory's Schmidt telescope, July 20, 1969.
Regular readers of The Catholic Astronomer are familiar with this photograph, found at the top of the blog's home page. But who is the Pope in this photo, and why is he looking through a telescope?
It is Pope Paul VI, canonized a saint today along with Archbishop Oscar Romero and four others. In his time as the Supreme Pontiff, he oversaw the completion of the Second Vatican Council, and he was the first Pope in modern times to travel abroad from the Vatican when addressed the United Nations assembly in New York in 1965.
The photo was taken on July 20, 1969 (technically, the morning of July 21 in Italy) at one of the telescope domes of the Vatican Observatory, located at the Pontifical villas in Castel Gandolfo. The other man in the photo is Fr. Daniel O'Connell SJ, the director of the Vatican Observatory at that time. The telescope is a Schmidt with 98-cm primary mirror and a 240-cm focal length, and was the primary telescope of the Vatican Observatory from its installation in 1957 until the mid-1980s when light pollution made the location unserviceable for good astronomy. It was used primarily for stellar spectroscopy and polarimetry, and for studies of the evolution of star clusters.
Pope St. Paul VI watching the Apollo 11 moon landing on TV and giving an address and blessing to the astronauts.
Attentive readers will recognize the date of the photo. It is, of course, the date of the landing of Apollo 11 on the surface of the moon. Pope St. Paul VI made a visit to the telescopes of the Observatory for the occasion, and watched the moon landing on TV from inside the Schmidt dome. From there, he also gave an address and blessing to the astronauts. The embedded video below shows coverage of the event. (Skip to 4:20 for his address in English.) He said, "Here, from His Observatory at Castel Gandolfo, near Rome, Pope Paul the Sixth is speaking to you astronauts. Honour, greetings and blessings to you, conquerors of the Moon, pale lamp of our nights and out dreams! Bring to her, with your living presence, the voice of the spirit, a hymn to God, our Creator and our Father. We are close to you, with our good wishes and with our prayers . Together with the whole Catholic Church, Pope Paul the Sixth salutes you." (Text taken from the archived documents on the Vatican website.)
Vatican Observatory to Host First Ever Workshop on Meteorite Curation
(Press Release from the Vatican Observatory)
The Vatican Observatory will host the first ever workshop on the Curation of Meteorites and Extraterrestrial Samples at its headquarters in the Papal gardens of Castel Gandolfo. Held from September 10-13, the meeting will bring together an international group of meteorite and extraterrestrial sample curators to exchange ideas, discuss best practices, and to explore ways to better serve the scientific community.
Thirty curators and collections managers will be at this meeting, representing 27 scientific institutions from around the world. These include museums, universities, and institutions throughout Europe, the United States, Canada, Russia, Morocco, and Japan. The curators not only care for meteorite collections, but also specimens gathered from space missions, such as the NASA Apollo moon rocks and the specimens from the Hayabusa mission to the asteroid 25143 Itokawa.
“The community of curators has been trying to organize itself for many years,” says Br. Robert Macke, S.J., the curator of the Vatican meteorite collection and one of the organizers of the workshop. “This workshop represents a wonderful opportunity for us, and I am excited and pleased that the Vatican Observatory can host such an important meeting.” The meeting is sponsored by the Vatican Observatory and the Meteoritical Society.
“It will be a good occasion to familiarize ourselves with the different collections and how they are curated,” says Ludovic Ferrière, co-curator of meteorites at the Natural History Museum of Vienna, Austria, and co-coordinator of the workshop. He adds, “A number of different topics will be discussed, some historical aspects of course, but also about the curation of future sample-return missions and the associated technical challenges and current issues.”
In addition to sharing information about the collections under their care, curators will address topics of interest to the meteorite community. These include the allocation of specimens for research, legal concerns about ownership and acquisition, recording and sharing information about specimens and the research conducted on them, growing the collections to better serve the scientific community, and conserving specimens for the future.
“One of the main purposes of curation is to make precious samples available to science for several generations,” says Ferrière.
“For years, meteorite curators have had to figure things out independently,” says Macke, “Now we are finally coming together as a community.”
Meteorites are found every day, and planned space missions will gather even more specimens. The future also promises new and better instrumentation for research. Curators must plan for the future, and this meeting will help them do that.
Asteroids Named for Jesuits
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.
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)
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.
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.
(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!
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.
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.
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.
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.
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.