Archive for the ‘Astrophysics’ Category

Artist’s impression of the Kepler telescope [credit: Wikipedia]


So said researchers in their 2015 study which had that title. Then a third planet was seen.

In the abstract they say:

Methods. Our search through two separate pipelines led to the independent discovery of K2-19b and c, a two-planet system of Neptune-sized objects (4.2 and 7.2 R⊕), orbiting a K dwarf extremely close to the 3:2 mean motion resonance. The two planets each show transits, sometimes simultaneously owing to their proximity to resonance and the alignment of conjunctions.

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The rotation of Venus

Posted: October 25, 2019 by oldbrew in Astrophysics, research, Uncertainty
Tags: ,

Credit: infobarrel.com


Not mentioned in the report (or anywhere else we know of) is that 19 Venus rotations very closely match the period of 13 lunar tropical years of 13 orbits/rotations each: (169 * 27.321582 days) / 19 = 243.01827 days. This matches the 1991 Magellan observation of the Venusian rotation period 243.0185 days and is very close to the current estimate, which is that it averages 243.0212 +- .00006 days but seems to have a small degree of variability, for reasons yet to be confirmed.

Venus is covered in a thick layer of clouds, one reason that it appears so bright in the sky, says Phys.org.

Ancient astronomers had a good idea of what (since Copernicus) we know as its orbital period; the modern measurement is that Venus takes 224.65 days to complete one revolution around the Sun, a Venusian year.

Because of the clouds, however, it has been difficult to measure the length of the Venusian day since the nominal method of watching a visible surface feature rotate around 360 degrees is not possible.

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There doesn’t seem to be any online discussion of this planetary system, first seen in 2014 – but it turns out be interesting anyway.

This is a Lucas series set-up, the planets being b, c, and d in order of proximity to the star.

Starting with the orbits:
19 b = 203.006394 days
10 c = 203.03005
7 d = 203.1565
(data: exoplanet.eu)

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Mr Yoshimura would agree…

Posted: October 22, 2019 by oldbrew in Astrophysics, Cycles
Tags: ,


…with the period of ~2500 years in our 2015 blog post: Why Phi? – Jupiter, Saturn and the de Vries cycle (we use 2503y).

Or he might do, if he had read it. More correctly, we agree with him.

In the second paragraph of the introduction in his article of December 1978 in the Astrophysical Journal, which has a rather long title related to the solar cycle, he writes:

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As this is going on, cosmic rays are near a record high since measurements began. Researchers are using natural cosmic rays this time.

CERN’s colossal complex of accelerators is in the midst of a two-year shutdown for upgrade work.

But that doesn’t mean all experiments at the Laboratory have ceased to operate.

The CLOUD experiment, for example, has just started a data run that will last until the end of November, reports Phys.org.

The CLOUD experiment studies how ions produced by high-energy particles called cosmic rays affect aerosol particles, clouds and the climate.

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The Kepler-42 system as compared to the Jovian system [credit: NASA/JPL-Caltech]

The headline was NASA’s joke about both the size and the short orbit periods (all less than two days) of the three planets in the Kepler-42 system.

The discovery of this system dates back to 2012, but there don’t seem to be any numbers on resonant periods, so we’ll supply some now.

Wikipedia says:
‘Kepler-42, formerly known as KOI-961, is a red dwarf located in the constellation Cygnus and approximately 131 light years from the Sun. It has three known extrasolar planets, all of which are smaller than Earth in radius, and likely also in mass.’

‘On 10 January 2012, using the Kepler Space Telescope three transiting planets were discovered in orbit around Kepler-42. These planets’ radii range from approximately those of Mars to Venus. The Kepler-42 system is only the second known system containing planets of Earth’s radius or smaller (the first was the Kepler-20 system). These planets’ orbits are also compact, making the system (whose host star itself has a radius comparable to those of some hot Jupiters) resemble the moon systems of giant planets such as Jupiter or Saturn more than it does the Solar System.’

The three planets in order of distance from their star (nearest first) are c,b and d. They all have very short orbit periods ranging from under half a day to less than two days, and the star has only 13% of the power of our Sun.

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Pairs or multiple systems of stars which orbit their common center of mass. If we can measure and understand their orbital motion, we can estimate the stellar masses.


Relatively nearby, that is…

‘Upsilon Andromedae is located fairly close to the Solar System… (44 light years). Upsilon Andromedae A has an apparent magnitude of +4.09, making it visible to the naked eye even under moderately light-polluted skies, about 10 degrees east of the Andromeda Galaxy.’ – Wikipedia

The larger of the binary stars is ups_And A, which has 4 planets orbiting it: b,c,d and e.

The information on this star system was recently updated, so let’s have a look.

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Credits: NASA’s Goddard Space Flight Center/Chris Smith


Following the report we analyse the orbital data for evidence of resonances.

A planet discovered by NASA’s TESS has pointed the way to additional worlds orbiting the same star, one of which is located in the star’s habitable zone, reports SciTechDaily.

If made of rock, this planet may be around twice Earth’s size.

The new worlds orbit a star named GJ 357, an M-type dwarf about one-third the Sun’s mass and size and about 40% cooler that our star. The system is located 31 light-years away in the constellation Hydra.

In February, TESS cameras caught the star dimming slightly every 3.9 days, revealing the presence of a transiting exoplanet — a world beyond our solar system — that passes across the face of its star during every orbit and briefly dims the star’s light.

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Moons of Pluto


This one may have slipped through the net, so to speak. The link to Pluto is explained below.

Star HD 40307 has six planets orbiting between 7 and 198 days, but here the focus will be on the outer three: e, f and g. These were reported in 2012 (whereas b, c, and d were found in 2008).

However, it seems the resonances described below have been overlooked, if lack of related internet search results can be relied on.

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Credit: NASA’s Goddard Space Flight Center / Scott Wiessinger


Quoting from the abstract of the study in Nature Astronomy:
‘The planets orbit close to a mean-motion resonant chain, with periods (3.36 days, 5.66 days and 11.38 days, respectively) near ratios of small integers (5:3 and 2:1).’

One of the astronomers said: “For TOI-270, these planets line up like pearls on a string. That’s a very interesting thing because it lets us study their dynamical behavior. And you can almost expect, if there are more planets, the next one would be somewhere further out, at another integer ratio.”

“There is a good possibility that the system hosts other planets, further out from planet d, that might well lie within the habitable zone. Planet d, with an 11-day orbit, is about 10 million kilometers out from the star.”

In fact the distance-to-star ratios of the planets (named b,c and d) are very similar:
b:c = 1:1.542 and c:d = 1:1.553 (for comparison Earth:Mars is 1:1.524).

NASA’s Transiting Exoplanet Survey Satellite, or TESS, has discovered three new planets that are among the smallest, nearest exoplanets known to date, reports Tech Explorist.

The planets circle a star only 73 light-years away and incorporate a small, rough super-Earth and two sub-Neptunes — planets about a large portion of the size of our own icy giant.

The sub-Neptune farthest out from the star seems, by all accounts, to be inside a temperate zone, implying that the highest point of the planet’s atmosphere is inside a temperature extend that could support a few types of life.

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Quiet sun [image credit: NASA]

NASA finally agrees with our model estimate for cycle 25 published in 2013. It’ll be interesting to see how this pans out. Leif Svalgaard predicted that cycle 25 would be higher than 24, but lower than cycle 20.

Research now underway may have found a reliable new method to predict this solar activity. The Sun’s activity rises and falls in an 11-year cycle. The forecast for the next solar cycle says it will be the weakest of the last 200 years. The maximum of this next cycle – measured in terms of sunspot number, a standard measure of solar activity level – could be 30 to 50% lower than the most recent one. The results show that the next cycle will start in 2020 and reach its maximum in 2025.

The new research was led by Irina Kitiashvili, a researcher with the Bay Area Environmental Research Institute at NASA’s Ames Research Center, in California’s Silicon Valley. It combined observations from two NASA space missions – the Solar and Heliospheric Observatory and the Solar Dynamics Observatory – with data collected since 1976 from the ground-based National Solar Observatory.

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A recent review article on PNAS titled ‘Astronomical metronome of geological consequence’ by Linda Hinnov makes interesting reading for talkshoppers.

A Brief Retrospective
In geology, a reliable “metronome” in the geologic record with a sufficiently short repeat time would greatly enhance the resolving power of the geologic timescale. Astronomers recognized the potential importance of a dominant 405-ky cycle in Earth’s orbital eccentricity variation for supplying such a metronome (2, 3), leading geologists to turn to the stratigraphic record of astronomically forced paleoclimate change to search for this cycle. In fact, one of the first geological studies to describe 405-ky scale stratigraphic cycling was on the Triassic–Jurassic Newark Basin lacustrine strata (4, 5) recovered in the National Science Foundation-funded Newark Basin Coring Project, in which each of the prominent 60-m-thick McLaughlin cycles in the cored sequence was assigned a 412.885- ky periodicity based on a now-legacy analytical astronomical solution, BRE74/BER78 (6, 7). Since the 1990s, there have been dozens of reports for strong 405-ky scale cycles in stratigraphic sequences from around the world that appear to bear out this astronomical calculation (8).

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Lift-off is scheduled for 2:51GMT on the 15th July 2019

Our friends Ned Nikolov and Karl Zeller will be keen to see the data from the Chandrayaan 2 lunar mission scheduled for take-off next week. Among many other experiments planned, the rover will be measuring surface thermal conductivity – a key factor in estimating the global lunar surface temperature.

The daily mail reports:

India’s space agency is preparing to launch its ambitious Chandrayaan-2 mission next week which is set to land near the currently unexplored south pole of the moon.

Chandrayaan-2 will blast off from the Satish Dhawan Space Center at Sriharikota on the country’s south west coast at 2.51am (10.21pm BST) on July 15.

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An important new solar paper by Prof Valentina Zharkova and co-authors S. J. Shepherd, S. I. Zharkov & E. Popova  published in ‘Nature’ has incorporated the solar-planetary theory we’ve been researching and advancing here at the talkshop over the last decade. As well as further developing her previous double dynamo theory which now accounts for the last several millennium’s solar grand minima and maxima, she includes discussion of Fairbridge, Mackey, Shirley, Charvatova and Abreu et al’s work. Central to the new hypothesis is the motion of the Sun around the barycentre of the solar system, described as the Solar Inertial Motion [SIM].

Left plot: the example of SIM trajectories of the Sun about the barycenter calculated from 1950 until 210034. Right plot: the cone of expanding SIM orbits of the Sun35 with the top showing 2D orbit projections similar to the left plot. Here there are three complete SIM orbits of the Sun, each of which takes about 179 years. Each solar orbit consists of about eight, 22-year solar cycles35. The total time span is, therefore, three 179-year solar cycles31, or about 600 years. Source: Adapted from Mackey35. Reproduced with permission from the Coastal Education and Research Foundation, Inc

Following my discussion with her at dinner following her talk in London last year, Zharkova now agrees with us that the SIM induced by planetary motion affects sunspot production and solar activity levels.

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Kepler-47 system [Image Credit: NASA/JPL Caltech/T. Pyle]


Astronomers have discovered a third planet in the Kepler-47 system, securing the system’s title as the most interesting of the binary-star worlds, says NASA’s Exoplanet Exploration team.

Using data from NASA’s Kepler space telescope, a team of researchers, led by astronomers at San Diego State University, detected the new Neptune-to-Saturn-size planet orbiting between two previously known planets.

With its three planets orbiting two suns, Kepler-47 is the only known multi-planet circumbinary system. Circumbinary planets are those that orbit two stars.

Continued here.
– – –
Now at the Talkshop let’s take a quick look at the data.

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Why Phi? – the Kepler-47 circumbinary system

Posted: April 16, 2019 by oldbrew in Astrophysics, News, Phi
Tags: ,

Kepler Space Telescope [credit: NASA]


A headline at Phys.org today reads:
‘Astronomers discover third planet in the Kepler-47 circumbinary system’

The report starts:
‘Astronomers have discovered a third planet in the Kepler-47 system, securing the system’s title as the most interesting of the binary-star worlds. Using data from NASA’s Kepler space telescope, a team of researchers, led by astronomers at San Diego State University, detected the new Neptune-to-Saturn-size planet orbiting between two previously known planets.

With its three planets orbiting two suns, Kepler-47 is the only known multi-planet circumbinary system. Circumbinary planets are those that orbit two stars.’

In this system the two stars orbit each other about every 7.45 days.

What can the latest information tell us about these planets, including newly discovered planet ‘d’?

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Coronal rain [image credit: NASA’s Solar Dynamics Observatory]


We’re told “The physics is literally the same” for the Earth’s rain and the Sun’s plasma showers, except that on the Sun the scale is much bigger than the entire Earth.

It’s one of the most enduring mysteries of the Sun: why the superheated surface of this great ball of glowing plasma is actually cooler than its outer atmosphere, called the corona.

Scientists now have a new explanation for this hotly debated topic says ScienceAlert, and the answer was hidden in a strange solar phenomenon that’s never been observed quite like this before: a deluge of plasma rain falling within newly discovered magnetic structures called Raining Null Point Topologies.

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Pairs or multiple systems of stars which orbit their common center of mass. If we can measure and understand their orbital motion, we can estimate the stellar masses.

How does this work? The two massive stars in question are orbiting each other at a distance of 180 AU (astronomical units), six times greater than that of Neptune to the Sun. Each orbit may take nearly 600 years.

Scientists from the RIKEN Cluster for Pioneering Research in Japan, Chalmers University of Technology in Sweden and the University of Virginia in the USA and collaborators have made observations of a molecular cloud that is collapsing to form two massive protostars that will eventually become a binary star system, reports Phys.org.

While it is known that most massive stars possess orbiting stellar companions it has been unclear how this comes about—for example, are the stars born together from a common spiraling gas disk at the center of a collapsing cloud, or do they pair up later by chance encounters in a crowded star cluster.

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Spiral galaxy NGC 5457 aka the Pinwheel Galaxy [image credit: European Space Agency & NASA]


OK, that’s not the original title of the article below – but it sounded a bit more interesting from a layman’s perspective 🙂

The rotation of stars in galaxies such as the Milky Way is puzzling, says Phys.org.

The orbital speeds of stars should decrease with their distance from the center of the galaxy, but in fact, stars in the middle and outer regions of galaxies have the same rotational speed.

This may be due to the gravitational effect of matter that we can’t see. But although researchers have been seeking it for decades, the existence of dark matter has yet to be definitively proven and we still don’t know what it might be made of.

With this in mind, the physicists Dmitri Ryutov, Dmitry Budker and Victor Flambaum have suggested that the rotational dynamics of galaxies might be explained by other factors. They hypothesize that the mass of photons, which are particles of light, might be responsible.

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During a total solar eclipse, the Sun’s corona and prominences are visible to the naked eye [image credit: Luc Viatour / https://Lucnix.be ]


The Sun continues to pose questions for scientists, such as the way solar cycle variability works and the surprisingly intense heat of its corona, compared to its surface.

A team of scientists who collected numerous observations of last summer’s total solar eclipse via telescopes and electronic cameras has used the data to better understand motions within the solar corona, the Sun’s outer atmosphere, says Space Reporter.

Jay Pasachoff of Williams College in Williamstown, MA, who led the team in observing the eclipse in Salem, Oregon, presented their findings to the 232nd Meeting of the American Astronomical Society (AAS) in early June.

His team has observed numerous solar eclipses during various times in the 11-year sunspot cycle.

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