Astronomy

Identifying cluster of exoplanets between Deneb and Vega

Identifying cluster of exoplanets between Deneb and Vega

I noticed an interesting patern of exoplanets.

Is this a known phenomenon?


That's the field the Kepler telescope was observing during its primary mission (before the second reaction wheel failure). The shape is due to the detector array.

I.e. this is not a real pattern in the actual distribution of exoplanets, it's a consequence of how the observations were done.


Kepler Stares at Neptune

For the first four years of the mission, Kepler stared at a single 12° patch of the sky between the bright stars Deneb, in the constellation Cygnus, and Vega, in Lyra, where it found several thousand exoplanet candidates. But when the second of the spacecraft's four reaction wheels failed in 2013, Kepler was no longer able to point accurately at its original target, so scientists devised a new way to point the spacecraft using the remaining two reaction wheels and photon pressure from sunlight. The new mission was dubbed K2.

Because of the new pointing method, K2 is limited to looking at fields along the plane of our solar system, but this also offers new ways to use the telescope's sensitive detectors. From November 2014 to January 2015, Kepler's field included the planet Neptune. Amy Simon, a planetary scientist at NASA’s Goddard Space Flight Center, looked for the faint signal of moving clouds embedded within Neptune's light curve. The Kepler observations are unique, said Simon, because they allow us to see the light curve of an object close enough to image and resolve cloud features. These observations prove that rapid variations in light curves of brown dwarfs and exoplanets can be caused by changing clouds.

Kepler is in an Earth-trailing heliocentric orbit, which just means that it's in orbit around the Sun and lagging behind the Earth, falling behind at the rate of 7.3 days per year. At the time of the Neptune observations, the spacecraft was trailing the Earth by about 6 weeks, or a little over 100 million kilometers. From this orbit, the K2 mission has identified hundreds of new exoplanet candidates.


Characteristics

Cygnus constellation

The constellation Cygnus is a large constellation located in the northern celestial hemisphere. It has many bright stars that are well known, including the star Deneb, which is the head of the Northern Cross.

The Swan comes from the Cygnus greek mythology story of the beautiful Leda, who bore twin sons for Zeus, hatched from an egg. Zeus had disguised himself as a swan to rescue Leda, and in his happiness, he placed the swan into the sky.

The Cygnus (constellation) occupies an area of 804 square degrees. The neighboring constellations are Cepheus, Draco, Lacerta, Lyra, Pegasus, and Vulpecula. For home stargazers, Cygnus has many exciting stars and deep-sky objects to view.

It contains the amazing Northern Cross asterism, well known around the globe. It also offers the amazing Fireworks Galaxy, the North America Galaxy, and the Cygnus x-1, a source of a-rays in the universe.

Cygnus is not a Zodiac sign, she is a beautiful serene Swan, floating across the sky. The Cygnus star system dates back over 3000 years (1).

What does Cygnus constellation look like?

ICygnus is a beautiful swan. She flies through the heavens, like an Angel, with wings outstretched on either side. When Zeus, King of the Gods, noticed Leda, he fell in love with her.

Disguising himself as a swan, he rescued her from an Eagle. The swan represents a magnificent creature of love, positiveness, and serenity. In the sky, Cygnus is large and imposing. She is a full-body creature, unlike some other constellations that are only half-formed.

In the sky, the constellation of Cygnus is depicted by a number of bright stars. Most notably, they form a well-defined cross, also known as the Northern Cross. The famous star, Deneb, lies at the head of the Cross. Sadr lies in the middle.

For many people, Cygnus is the Cross, rather than the Swan. It is easy to see the Cross, as each arm is defined by the bright stars Rukh and Gienah.

If you love mystical stories, imagine a glorious swan with a long neck pointing slightly down and forwards. Her tail is stretched out behind her as she flies. On either side, huge wings help her glide silently amongst the stars. To complete the image, color the swan in a snow-white color – a stunning apparition in the sky.

How far is Cygnus constellation from earth?

When viewing a constellation from Earth, it appears as if all the stars and celestial bodies are on one flat plane. In reality, this is not correct! They all lie at different distances away, measured in light-years. Some stars may be as close as 40 light-years. Deep-sky objects may be as far as millions of light-years away.

To give some idea, Cygnus brightest star, Deneb is 1,400 light-years away from Earth. Sadr, the star at the intersection of the Cross is about 1,800 light-years distant from the earth. Gienah is 72.7 light-years away and Rukh, also known as Farwaris, is 170 light-years away.

Albireo is a binary star system that lies about 380 light-years away. Zeta Cygni is a yellow star that lies about 151 light-years away from Earth. Tau Cygni is closer at only 68.2 light-years away.

The distance from Earth to Messier 29, an open cluster, is about 4,000 light-years. The spectacular Fireworks Galaxy is a massive 22 million light-years away from Earth.

Taking into account the brightest stars and their individual distances, the average distance to the Cygnus constellation from Earth is about 577 light-years. If you consider the deep-sky galaxies, the distance is around millions of light-years.


Meet Deneb, the Bright but Distant Star

By: Daniel Johnson October 15, 2018 1

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Deneb Vitals

Physical Characteristics

In physics, the inverse square law describes through mathematics what humans already perceive and understand intuitively: The farther away we are from a light source, the dimmer it appears. So it’s only a simple matter of logic to deduce that if a light source appears to be very bright, but is also known to be very far away, it must possess great luminosity.

Such is the case with Deneb, a 1st magnitude star and one of the most distant stars you can see without optical aid. Deneb is a bluish-white supergiant around 200 times the size of the Sun and burning through its fuel at a rapid rate.

Deneb shines bright in the constellation Cygnus.
Bob King

Some well-known bright stars such as Vega, Sirius, and Alpha Centauri appear bright in our sky primarily because they are relatively close to us. While Vega and Sirius are certainly more luminous than the Sun, it’s the close distance (only 8.6 light-years for Sirius) that makes them seem so bright.

But for Deneb, the story is entirely different. This star appears bright not because it’s close — in fact, it’s very far away — but because it has enough luminosity to overcome great distance and still shine in our sky at magnitude 1.25. There is uncertainty surrounding Deneb’s distance from us, making it challenging to determine characteristics such as radius, mass, and others. But it’s estimated that the star is somewhere between 50,000 and 200,000 times as luminous as the Sun. Regardless of the precise luminosity, there is no doubt that this is a star with tremendous energy output. If Deneb could swap places with Vega, it would outshine Venus in our sky and cast shadows on Earth.

So how far away is it? That’s a tough question, and one that isn’t easy for astronomers to answer. The distance to some close stars can be determined using the parallax method — observing the star’s apparent shift in the sky relative to more distant stars as Earth orbits the Sun. But for faraway stars, the parallax method soon becomes inadequate. Some estimates have placed Deneb’s distance at a remote 2,600 or 3,000 light-years, while one analysis of data from the ESA’s Hipparcos (the “high precision parallax collecting satellite”) puts the figure closer to 1,500 light-years. The question of Deneb’s distance remains uncertain and might stay that way as, unfortunately, Deneb is too bright for the ESA’s more advanced Gaia satellite (the successor to Hipparcos).

But no matter the precise distance, there’s no question that Deneb is farther away than most of the familiar stars in our sky.

Origin / Mythology

A map of the constellation Cygnus, the Swan.
Sky & Telescope

Deneb is located in the constellation Cygnus — a Latin form of the word “swan” that is in turn an adaptation of Greek. Deneb is located on what could be considered the “tail” of the swan. To the ancient Greeks, the constellation Cygnus featured in the telling of multiple competing tales involving swans. But it appears Cygnus didn’t represent a swan in all cultures. In Arabic, Deneb was known as the “tail of the hen” instead. In Chinese mythology, however, Deneb wasn’t a bird, but instead formed part of a bridge across a “river” — the Milky Way itself.

How to See Deneb

Deneb, along with stars Vega and Altair, mark the corners of the Summer Triangle, an asterism that sits high in the sky during summer.
Stellarium

Deneb is the brightest star in Cygnus. Additionally, it’s an easily spotted member of two asterisms (groups of stars that aren’t official constellations): the Northern Cross and the Summer Triangle. The Northern Cross is simply an abbreviated version of Cygnus: the main body of the swan minus the ends of the wings and feet. The Summer Triangle — so called because it’s high in the sky during summer evenings — consists of Deneb, Vega, and Altair, making it an easy task to find the others once one star is located.

Observers with clear, dark skies will also note that Cygnus sits within the band of the Milky Way (remember, it’s a bridge crossing the Milky Way in Chinese myth). Deneb is high enough in the sky that it’s possible to view it year round in the Northern Hemisphere. (If you can wait until the year 9800, Deneb will take the place of Polaris as our North Star.) While you’re observing Deneb, keep in mind that you’re looking at an extremely powerful object that is considerably farther away than most other common stars.


Location and visibility

Where is Lyra constellation located?

Lyra is a small constellation and you may think that it is difficult to locate in the sky. It is not! The main bright star, Vega, forms part of the well-defined asterism, or star pattern, called the Summer Triangle. Once you find these three stars, you can imagine the musical Lyra harp in the sky.

Lyra is a northern constellation and is the 52nd largest constellation of the 88 named constellations. It occupies an area of 286 square degrees. Lyra lies in the fourth quadrant of the northern hemisphere, NQ4.

A quadrant is essentially a quarter of a circle, which allows astronomers to measure the altitude of objects above the horizon. You can see the music constellation at latitudes between +90° and −40°.

To find the Lyra constellation location, you can find Hercules, the Great Warrior. Lyra lies near to his left hand that holds the head of the dreaded Medusa. Also near Lyra is Cygnus, the Swan.

Cygnus is easily located because it is home to the famous Northern Cross, The Northern Cross is indicated by the star Deneb at the top and the star Albireo at the bottom. Lyra lies between Cygnus and Hercules (17).

When is Lyra constellation visible?

Lyra, the Orpheus constellation, is visible in both the northern and southern hemispheres. But, the best views are in the northern regions.

In the northern hemisphere – In April and May, Lyra appears low on the horizon in the northeast at about 11pm. It gradually moves higher in the sky before day breaks. From June to July the constellation appears in the east around 10 pm gradually moving higher until it is directly overhead.

From August to September Lyra appears overhead at around 10pm. In October, November, and December it is visible high in the western sky between 6pm and 7pm. This is a great time to take the family out for some stargazing and teach the kids about Lyra astronomy.

In the southern hemisphere – In July and August, you can see Lyra very low on the northern horizon between 8pm to 11pm. The constellation remains low on the horizon moving westward for around 5 hours before dipping below the horizon.

Remember – in the southern hemisphere, all constellations appear upside down.

How to find Lyra constellation?

Depending on your budget, plan to spend from $250 to $900 on a telescope that will give a lifetime of viewing.

The Celestron AstroFi 102 Telescope is an exciting computerized telescope, ideal for a family who has progressed from manual models. It has integrated WiFi and includes a Celestron SkyPortal app for iPhone, iPad, and Android devices.

The scope has a classic Maksutov Cassegrain design with a 102mm aperture and fully coated high-quality glass optics.

It comes with 2 Kellner eyepieces, a 25mm and a 10mm, a FinderScope, a star diagonal, and an integrated smartphone adapter. The tripod has an adjustable height, which is great for smaller children.

The accessory tray is convenient, allowing you to keep all your bits and pieces close at hand. The Celestron AstroFi 102 Telescope gives amazing views of the vega constellation. At around $400, it is a great investment for a family hobby.


Kepler Stares at Neptune

For the first four years of the mission, Kepler stared at a single 12° patch of the sky between the bright stars Deneb, in the constellation Cygnus, and Vega, in Lyra, where it found several thousand exoplanet candidates. But when the second of the spacecraft's four reaction wheels failed in 2013, Kepler was no longer able to point accurately at its original target, so scientists devised a new way to point the spacecraft using the remaining two reaction wheels and photon pressure from sunlight. The new mission was dubbed K2.

Because of the new pointing method, K2 is limited to looking at fields along the plane of our solar system, but this also offers new ways to use the telescope's sensitive detectors. From November 2014 to January 2015, Kepler's field included the planet Neptune. Amy Simon, a planetary scientist at NASA’s Goddard Space Flight Center, looked for the faint signal of moving clouds embedded within Neptune's light curve. The Kepler observations are unique, said Simon, because they allow us to see the light curve of an object close enough to image and resolve cloud features. These observations prove that rapid variations in light curves of brown dwarfs and exoplanets can be caused by changing clouds.

Kepler is in an Earth-trailing heliocentric orbit, which just means that it's in orbit around the Sun and lagging behind the Earth, falling behind at the rate of 7.3 days per year. At the time of the Neptune observations, the spacecraft was trailing the Earth by about 6 weeks, or a little over 100 million kilometers. From this orbit, the K2 mission has identified hundreds of new exoplanet candidates.


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 &ldquoSummer Triangle&rdquo 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. [Stunning Night Sky Photos for September 2014]

Vega is located 25 light-years away, has a diameter approximately three times that of our sun and is 58 times more luminous. In January 2002, astronomers at the Harvard-Smithsonian Center for Astrophysics announced that features observed in a cloud of dust swirling around Vega may be the signatures of an unseen exoplanet in an eccentric orbit around the star.

And observations of Vega in 1983 with the Infrared Astronomy Satellite provided the first evidence for large dust particles around another star, probably debris related to the formation of planets. This discovery likely inspired Carl Saganto place a planetorbiting Vega in his famous novel "Contact."

Vega also was the first star ever to be photographed. The historic photograph was made using the daguerreotype process at Harvard Observatory overnight on July 16-17, 1850. A 15-inch refractor was used, but nonetheless it still took an exposure of 100 seconds for Vega&rsquos image to register.

Vega's constellation, Lyra, was supposed to represent Apollo&rsquos harp. Officially, Lyra is a lyre — a stringed instrument of the harp family used to accompany a singer or reader of poetry, especially in ancient Greece. Six stars form a combined geometric pattern of a parallelogram and an equal-sided triangle attached at its northern corner. Vega gleams at the western point of the triangle.

But there are other interesting sights to explore here as well. Epsilon Lyrae, at the northern point of the little triangle where Vega is located, is known as the "double-double" star. Those with good eyesight discover that Epsilon is really a close pair of stars. Binoculars readily separate the two, while a moderately large telescope shows each one divided again into two stars.

The star Sheliak is one of the two that forms the southern side of the parallelogram it appears to diminish by half its normal brightness about every 13 days when it&rsquos eclipsed by a darker companion star. Between this winking star and its neighbor, Sulafat, is the famous Ring Nebula, faintly glowing like a ghostly doughnut or a cosmic smoke ring. Visible only in large telescopes, the nebula appears as an oval ring around a star. Millions of years ago, this star exploded, hurling out great masses of gas. We see the star now through the thin part of this gaseous envelope.


Identifying cluster of exoplanets between Deneb and Vega - Astronomy

Tonight, look eastward during the evening hours, and it’s hard to miss the season’s signature star formation, called the Summer Triangle. Its stars – Vega, Deneb and Altair – are the first three to light up the eastern half of sky after sunset, and their bright and sparkling radiance is even visible from light-polluted cities or on a moonlit night.

Try looking first for the most prominent star in the eastern sky, which is Vega in the constellation Lyra the Harp. Vega is blue-white in color. It’s sometimes called the Harp Star. And many people recognize its constellation, Lyra, as a triangle of stars connected to a parallelogram.

The constellation Lyra the Harp.

It’s hard to gauge the humongous size of the Summer Triangle by looking at our little chart. A 12-inch ruler, when placed at an arm’s length from your eye, spans the approximate distance from Vega to the star Altair. And an outstretched hand more or less fills the gap between Vega and Deneb.

More than any other month, July is the month of the Summer Triangle. At mid-northern latitudes, the Summer Triangle’s stars – as if a trio of school kids on vacation – stay out from dusk till dawn, dancing amid the stars of our Milky Way galaxy. As our Earth turns tonight, Vega, Deneb and Altair travel westward across the sky. The Summer Triangle shines high overhead in the middle of the night, and sparkles in the west as the rose-colored dawn begins to color the sky.

The Summer Triangle, photographed by Susan Jensen in Odessa, Washington.

Our Summer Triangle series also includes:

Bottom line: The Summer Triangle consists of 3 bright stars in 3 different constellations. The brightest is Vega in the constellation Lyra.


The Night Sky This Month: July 2017

Photo of Comet V2 Johnson by José J. Chambó

The first real dark skies for the northern hemisphere occur only after about the 11th of July, which offers a perfect opportunity to view the Summer Triangle, an asterism made up of the bright stars Vega, Altair and Deneb, in the constellations of Lyra, Aquila and Cygnus respectively. Interestingly, a search for exoplanets in the area between Deneb and Vega has turned up 4,043 possible planets, of which about 50 or so are Earth-sized, and orbit their stars within their habitable zones. The full list of possible and confirmed planets in this area is available here.

In July, the full Moon is known as the Full Buck Moon in America, because it is at this time of the year that deer bucks’ antlers enter a high growth phase. Below are the Moon phases for July 2017:

First Quarter: 1st
Full Moon: 9th
Last Quarter: 16th
New Moon: 23rd

– Mercury sets soon after sunset for most of July. However, the little planet reaches its greatest eastern elongation from the Sun on the 30th of the month, when it will be 27.2 degrees away from the Sun. Look for Mercury low above the western horizon just after sunset during the last days of July.

– Venus dominates the pre-dawn sky during July, shining at magnitude -4.0 for almost the entire month. Rising at about 02:20 (BST) in the northeast, the planet reaches an elevation of 19 degrees above the eastern horizon on the 1st, but steadily gains height as the month wears on to reach an altitude of 25 degrees or so by month’s end. Look for Venus about 8 degrees south-eastward of the Pleiades during the first days of the July. As the month progresses, Venus will move between the Pleiades and the star Aldebaran to pass about 3 degrees to the upper leftward of Aldebaran on the 14th. Although Venus’ angular diameter will reduce from 18 arcseconds to 15 arcseconds, its illumination will increase from 63% to 74%, which means its brightness will remain largely unchanged during July.

– Mars is not visible at this time, being washed out by the Sun’s glare, and it will only reappear as a morning object at the end of August/beginning of September.

– Jupiter remains a conspicuous magnitude -2.0 object low above the south-western horizon before sunset as it continues its eastward motion through the constellation Virgo. Look for the King of the Planets close to the Moon on the first day of July, and again on the 28th, by which time it will be even lower above the west-south-western horizon when it sets at about 23:01 (BST) on the last days of July.

– Saturn starts July rising at 19:48 (BST) but rises progressively earlier as the month wears on, to rise at 17:43 (BST) on the 31st. The planet reached its point of closest approach to Earth on June 15th, which means that relatively speaking, it is still fairly close to us as it transits the constellation Sagittarius in which it now occupies an apparent spot just above the centre of the Milky Way. However, although it remains low on the horizon, it is nevertheless the brightest object low above the southern horizon, even though the planet will dim slightly from magnitude 0.1 to 0.3 as the July progresses.

Meteor Showers

July sees the arrival of the Southern Delta Aquarid Meteor Shower, which is suspected to be debris from Comet 96P Machholz. Although this meteor shower favors observers in the southern hemisphere, observers in northern tropical latitudes can observe the poorly-defined peak best between July 27th, and July 30th. Radiating from the star Skat in the constellation Aquarius, this shower usually delivers a maximum of around 15 -25 or so meteors per hour in the small hours just before dawn.

Deep Sky Objects

July brings the parabolic Comet V2 Johnson to within sixth or seventh magnitude, meaning that from a dark site, it will be visible in binoculars and even to the naked eye if seeing conditions are exceptionally good. Look for the comet in the constellation Virgo, where it will be at magnitude 7.5 only about 0.5 degrees to the northward of the star Kappa Virginis during the first days of July. The first really good opportunity to view the comet will occur on July 11th, when it will be close to the Hydra/Libra border, but still in Virgo, from whence it moves into Hydra on the 17th of the month. By the end of the month, the comet will be located less than one degree from the face-on spiral galaxy NGC 5556. By the end of July, Comet Johnson will become visible only to southern hemisphere observers as it continues its southward motion.


FINAL UPDATE: 4 May – 2:00 p.m. – The weather for tomorrow night is predicted to be lousy for observing, so we’re making the official call early to CANCEL tomorrow night’s event at Beaver Lake Nature Center. Stay tuned for an event announcement about The Mercury Transit happening on May 9th!

UPDATE: 28 April – 2:00 p.m. – Sadly, the cloud cover is not agreeable for observing tonight (as also reported by Glenn Coin at syracuse.com), so we are pushing the observing session off to next Thursday, May 5th. Stay tuned!

UPDATE: 28 April – 10:00 a.m. – The sky conditions for tonight are not looking good for observing. We’ll make a final call around 2:00 p.m. and, if necessary, plan for next Thursday instead.

Greetings, fellow astrophiles!

The time has come again to make our seasonal Thursday night trek [beaver lake announcement meetup.com event] to the Beaver Lake parking lot for views of the Nighttime Spring Sky. For 2016, we’ve the added bonus of having prime planetary viewing for the entire session, featuring Mercury to our West just after sunset (and even before if Bob Piekiel’s GOTO scope is ready) and Jupiter, biting at the feet of Leo the Lion, in the sky throughout – having reached opposition in early March.


Views from the 2006 Transit of Mercury. Photo from nationalgeographic.com

Mercury will be giving us a double-dose of observing in the next few weeks as we approach its Transit on the morning of May 9th (for which Bob Piekiel is hosting a special (and unusually early!) event at Baltimore Woods from 8 to 10 a.m. On Monday, May 9th – event notice to follow!). For those who managed a view of the Transit of Venus in 2012, this is your chance to say you saw the only two planetary Transits you can from Earth – you’ll then have to move to Mars to try to make any kind of inferior planet trifecta.


Google map for Beaver Lake Nature Center. Click to get directions.

The Thursday session at Beaver Lake will be our last chance to see any sign of the Orion Nebula (and it will be heroic observing at that, given how close to the tree line it may be by the time it’s dark enough), but M13 in Hercules, the Leo Triplet (shown at right – and they will not look this good from Beaver Lake! Image from wikipedia.org), several other notable Messier Objects, and whatever satellites happen to fly over will be on hand to keep the observing and conversation going.

By the usual ending time for the event, the bright star Vega in the constellation Lyra will just be rising above the Northeastern skyline, striking the chord to herald the soon-approaching return of Summer Skies and our views into the heart of our Milky Way Galaxy.


Watch the video: Golden Webinars Sara Seager - Mapping the Nearest Stars for Habitable or Inhabited Worlds (January 2022).