Posts Tagged ‘exoplanet’

Updated: Drake Equation Revisited

June 2, 2017

1 in 22,286 solar systems in the Milky Way host some form of life, such as plant, animal, human, etc.

1 in 42,507 solar systems in the Milky Way host human life.

1 in 59,316 solar systems in the Milky Way host advanced human life.

 

1 in 61,571 solid planets or moons in the Milky Way host some form of life, such as plant, animal, human, etc.

1 in 117,439 solid planets or moons in the Milky Way host human life.

1 in 163,878 solid planets or moons in the Milky Way host advanced human life.

 

1 in 7.43 solar systems/stars in the Milky Way have suns/stars similar to our own sun, SOL.

An estimated 6 trillion to 7 trillion human civilizations exist in our DERN Universe and in our space time configuration.

The estimated number of human civilizations that exist throughout all of Creation, is “in the vigintillions”, a number with 63 zeroes after it.


Total number of Identified Exoplanets: 3,499

Kepler Exoplanet Count: 2,491

Kepler:

Candidates: 4,034
Confirmed: 2,335
Small Habitable Zone Confirmed: 30

K2:

Candidates: 520
Confirmed: 156

(as of July 20, 2017)

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First Atmosphere detected around Earth sized exoplanet

April 7, 2017

April 6, 2017

Astronomers have detected an atmosphere around the super-Earth GJ 1132b. This marks the first detection of an atmosphere around a low-mass super-Earth, in terms of radius and mass the most Earth-like planet around which an atmosphere has yet been detected. Thus, this is a significant step on the path towards the detection of life on an exoplanet. The team, which includes researchers from the Max Planck Institute for Astronomy, used the 2.2-m ESO/MPG telescope in Chile to take images of the planet’s host star, GJ 1132, and measured the slight decrease in brightness as the planet and its atmosphere absorbed some of the starlight while passing directly in front of their host star.

While it’s not the detection of life on another planet, it’s an important step in the right direction: the detection of an atmosphere around the super-Earth GJ 1132b marks the first time an atmosphere has been detected around a planet with a mass and radius close to Earth’s mass and radius (1.6 Earth masses, 1.4 Earth radii).

Astronomers’ current strategy for finding life on another planet is to detect the chemical composition of that planet’s atmosphere, on the lookout for certain chemical imbalances that require the presence of living organisms as an explanation. In the case of our own Earth, the presence of large amounts of oxygen is such a trace.

We’re still a long way from that detection though. Until the work described in this article, the (few!) observations of light from exoplanet atmospheres all involved planets much more massive than Earth: gas giants—relatives of our own solar system’s Jupiter—and a large super-Earth with more than eight times the Earth’s mass. With the present observation, we’ve taken the first tentative steps into analyzing the atmosphere of smaller, lower-mass planets that are much more Earth-like in size and mass.

The planet in question, GJ 1132b, orbits the red dwarf star GJ 1132 in the southern constellation Vela, at a distance of 39 light-years from us. Recently, the system has come under scrutiny by a team led by John Southworth (Keele University, UK). The project was conceived, and the observations coordinated, by Luigi Mancini, formerly of the Max Planck Institute for Astronomy (MPIA) and now working at the University of Rome Tor Vergata. Additional MPIA team members were Paul Mollière and Thomas Henning.

The team used the GROND imager at the 2.2-m ESO/MPG telescope of the European Southern Observatory in Chile to observe the planet simultaneously in seven different wavelength bands. GJ 1132b is a transiting planet: From the perspective of an observer on Earth, it passes directly in front of its star every 1.6 days, blocking some of the star’s light.

The size of stars like GJ 1132 is well known from stellar models. From the fraction of starlight blocked by the planet, astronomers can deduce the planet’s size—in this case around 1.4 times the size of the Earth. Crucially, the new observations showed the planet to be larger at one of the infrared wavelengths than at the others. This suggests the presence of an atmosphere that is opaque to this specific infrared light (making the planet appear larger) but transparent at all the others. Different possible versions of the atmosphere were then simulated by team members at the University of Cambridge and the Max Planck Institute for Astronomy. According to those models, an atmosphere rich in water and methane would explain the observations very well.

The discovery comes with the usual exoplanet caveats: while somewhat larger than Earth, and with 1.6 times Earth’s mass (as determined by earlier measurements), observations to date do not provide sufficient data to decide how similar or dissimilar GJ 1132b is to Earth. Possibilities include a “water world” with an atmosphere of hot steam.

The presence of the atmosphere is a reason for cautious optimism. M dwarfs are the most common types of star, and show high levels of activity; for some set-ups, this activity (in the shape of flares and particle streams) can be expected to blow away nearby planets’ atmospheres. GJ 1132b provides a hopeful counterexample of an atmosphere that has endured for billion of years (that is, long enough for us to detect it). Given the great number of M dwarf stars, such atmospheres could mean that the preconditions for life are quite common in the universe.

In any case, the new observations make GJ 1132b a high-priority target for further study by instruments such as the Hubble Space Telescope, ESO’s Very Large Telescope, and the James Webb Space Telescope slated for launch in 2018.

The work described here has been published as J. Southworth et al., “Detection of the atmosphere of the 1.6 Earth mass exoplanet GJ 1132B” in the Astronomical Journal.

 

Visible Light Spectrum from Alien Planet Measured for 1st Time

April 22, 2015

Astronomers have detected an exoplanet’s visible-light spectrum directly for the first time ever, a milestone that could help bring many other alien worlds into clearer focus down the road.

Wide-field view of the sky around the star 51 Pegasi

Image showing the sky around the star 51 Pegasi in the northern constellation of Pegasus. This image was created from photographic material forming part of the Digitized Sky Survey 2. Credit: ESO/Digitized Sky Survey 2
(editor’s note: I believe the planet is to the left of the star in the center)

The scientists used the HARPS instrument on the European Southern Observatory’s 3.6-meter telescope at the La Silla Observatory in Chile to study the spectrum of visible light reflected off the exoplanet 51 Pegasi b, which lies about 50 light-years from Earth in the constellation Pegasus.

51 Pegasi b, a “hot Jupiter” gas giant that orbits close to its parent star, was spotted in 1995, when it became the first alien world ever discovered around a sunlike star. (The first exoplanets of any type were found in 1992 around a superdense, rotating stellar corpse called a pulsar.)

Researchers most often study exoplanet atmospheres by analyzing the starlight that passes through them when worlds cross their stars’ faces from Earth’s perspective. This method, known as transit spectroscopy, is restricted to use on systems in which the stars and planets align.

 

The new strategy used with 51 Pegasi b, on the other hand, does not depend on planetary transits and could thus find broader applicability, researchers said.

The technique offers other scientific advantages as well.

“This type of detection technique is of great scientific importance, as it allows us to measure the planet’s real mass and orbital inclination, which is essential to more fully understand the system,” study lead author Jorge Martins, of the Instituto de Astrofísica e Ciências do Espaço (IA) and the Universidade do Porto in Portugal, said in a statement.

“It also allows us to estimate the planet’s reflectivity, or albedo, which can be used to infer the composition of both the planet’s surface and atmosphere,” Martins added.

The new data suggest that 51 Pegasi b is highly reflective, a bit larger in diameter than Jupiter and about half as massive as our solar system’s biggest planet, researchers said.

The new observations by HARPS (which is short for High Accuracy Radial velocity Planet Searcher) provide a vital proof of concept for the new technique, which could really come into its own when employed with instruments on bigger telescopes, such as the European Southern Observatory’s Very Large Telescope (VLT), researchers said.

“We are now eagerly awaiting first light of the ESPRESSO spectrograph on the VLT so that we can do more detailed studies of this and other planetary systems,” said co-author Nuno Santos, also of the IA and Universidade do Porto.

The new study was published today (April 22) in the journal Astronomy & Astrophysics.

How to Find Vega, a Scintillating Star in a Cosmic Harp

September 5, 2014

How to Find Vega, a Scintillating Star in a Cosmic Harp.

Shining almost directly overhead as darkness falls these days is the brilliant bluish-white star Vega, in the constellation of Lyra, the Harp. 

Vega is the fifth-brightest star in the night sky, and the third-brightest visible from midnorthern latitudes, trailing just Sirius and Arcturus. Also, as seen from midnorthern latitudes such as New York or Madrid, Vega goes below the horizon for only about seven hours a day, meaning you can see it on any night of the year. 

As viewed from farther south, Vega — the brightest of the three stars forming the large “Summer Triangle” consisting of Vega, Altair and Deneb — lies below the horizon for a longer interval of time. Conversely, for Alaska, central and northern Canada and central and northern Europe, Vega never sets and is readily visible on any night of the year.

more at… http://www.space.com/27033-vega-star-harp-constellation-lyra.html

670px-Find-Your-Way-Around-the-Summer-Night-Sky-Step-2

 vega-lyra_sky-map