Terry's Astronomy Thread.

[Sky Kitten]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 20, 2013

-Low in the afterglow of sunset, Jupiter has drawn to within 8° of Venus, which shines to its lower right. Can you see Mercury yet, 3° to the lower right of Venus?

-These three planets about to swing through a "trio" together, as shown in the video below. They'll appear closest together in a tight little triangle, 2° on a side, next Sunday the 26th.

Astro Picture of the Day:
May 20, 2013

Source
One of the brightest galaxies in planet Earth's sky and similar in size to the Milky Way, big, beautiful spiral M81 lies 11.8 million light-years away in the northern constellation Ursa Major. This deep image of the region reveals details in the bright yellow core, but at the same time follows fainter features along the galaxy's gorgeous blue spiral arms and sweeping dust lanes. It also follows the expansive, arcing feature, known as Arp's loop, that seems to rise from the galaxy's disk at the right. Studied in the 1960s, Arp's loop has been thought to be a tidal tail, material pulled out of M81 by gravitational interaction with its large neighboring galaxy M82. But a recent investigation demonstrates that much of Arp's loop likely lies within our own galaxy. The loop's colors in visible and infrared light match the colors of pervasive clouds of dust, relatively unexplored galactic cirrus only a few hundred light-years above the plane of the Milky Way. Along with the Milky Way's stars, the dust clouds lie in the foreground of this remarkable view. M81's dwarf companion galaxy, Holmberg IX, can be seen just above and left of the large spiral. On the sky, this image spans about 0.5 degrees, about the size of the Full Moon.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Hello! I've returned from Algonquin Park on a very successful trip - and a very tiring one. Arrived home later than I would have liked due to traffic - departing at 3;30pm which should have got me home by around 7;30 had me instead arriving at 11;45. I'm very tired but that doesn't stop the fact I have to work in about 30 minutes ##.

What's in the sky tonight?
May 21, 2013

-The star near the waxing gibbous Moon this evening is Spica in Virgo.

-Venus (magnitude –3.9) is still quite low in the west-northwest in twilight, to the lower right of Jupiter. Watch as Venus and Jupiter draw together by about 1° per day. On May 17th they're still 11° apart. Their conjunction comes on the 28th, when they'll be 1° apart with Mercury right alongside.

Astro Picture of the Day:
May 21, 2013

Source
Once the famous sunset comet, PanSTARRS (C/2011 L4) is now visible all night from much of the northern hemisphere, bound for the outer solar system as it climbs high above the ecliptic plane. Dimmer and fading, the comet's broad dust tail is still growing, though. This widefield telescopic image was taken against the starry background of the constellation Cepheus on May 15. It shows the comet has developed an extensive anti-tail, dust trailing along the comet's orbit (to the left of the coma), stretching more than 3 degrees across the frame. Since the comet is just over 1.6 astronomical units from planet Earth, that corresponds to a distance of over 12 million kilometers. In late May Comet PanSTARRS will pass within a few degrees of the north celestial pole.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 22, 2013

-Tonight the Moon shines with Saturn. Although they look close together, the Moon is only 1.3 light-seconds from Earth while Saturn is 74 light-minutes in the background.

News Posted Today:
May 21, 2013
A Bright Flash in the (Lunar) Night


Astro Picture of the Day:
May 22, 2013

Source: My Camera
Your cosmic tea is ready, straight from the celestial teapot with a dash of milk from our local milky way. Enjoy - it's out of this world! This stellar scene is just one of many that laid before me during my trek to Algonquin Park. The teapot of Sagittarius is easily visible, which appears to dip ever so slightly into the Sagittarius cloud, one of the brightest bands of the galactic core that we can see. The Trifid nebula is easily visible to the upper right of the Teapot.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 23, 2013

-Starting from Saturn in the south-southeast as evening grows late, follow a diagonal line of five objects toward the lower left: Saturn, fainter Alpha Librae, the glaring Moon, Delta Scorpii, and Antares.

-Saturn (magnitude +0.2, in Libra) glows in the southeast during twilight, with Spica to its upper right and Arcturus twice as far to its upper left. It's highest in the south not long after dark.

Astro Picture of the Day:
May 23, 2013

Source: My Camera
This scene is found on the west beach on the Lake of Two Rivers in Algonquin Park. A canoe marks the foreground of the lake which has been cast an eerie green glow due to the northern lights roaming around in the distance. Also, a car drove by on the nearby highway whose headlights illuminated the midnight forest to create an intresting depth of field. There was no wind this night, and the water was perfectly still. It acted as if it was a mirror into the sky. The Northern Lights were caused by a geomagnetic storm that hit the earth May 17, 2013 due to an x-class flare that launched from the sun on May 15.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 24, 2013

-Jupiter, Venus, and Mercury, low in the afterglow of sunset, are now officially a "trio": they fit within a 5° circle. The means you could just about cover them with a golf ball at arm's length, and they'll fit in the view of most binoculars. They'll stay at least this close through next Wednesday the 29th. This evening, Venus and Mercury appear their closest together.

Full Moon (exact at 12:25 p.m. EDT tonight). The Moon is only two days from perigee, so it appears a tiny trace bigger than average.

The dazzling Moon occults (covers) the 2nd-magnitude star Beta Scorpii this evening for much of the eastern U.S. except the Northeast.

Astro Picture of the Day:
May 24, 2013

Source: My Camera
The Lake of Two Rivers in Algonquin Park was the benefactor of a large geomagnetic storm for those who were willing to look up. The storm came from an x-class solar flare that ejected out of the sun towards Earth on May 15th. At times, the auroras were luminescent enough to be seen inside cars. The auroras for the most part lasted the entire night and continued into the morning hours after sunrise - though by then, they were no longer visible. Purple auroras can be easily seen in this picture. Purple, Blue, Red and green are common colours of auroras where green is the lowest altitude, followed by purple, blue, and then red.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 25, 2013

-The Jupiter-Venus-Mercury trio continues shrinking. Above it, by contrast, the enormous Arch of Spring spans much of the western sky as twilight dims. Its highest part is the Pollux-and-Castor pair, roughly horizontal and about three finger-widths apart. Look far to the lower left of Pollux and Castor for Procyon, and farther to their lower right for Menkalinen and then bright Capella. Consult the video below for the planet dance.

Astro Picture of the Day:
May 25, 2013

Source: My Camera
So far, Sunspot AR1748 has produced more X-flares than every other sunspot of the past year combined. In summary, AR1748 has given us an X1.7-class flare (0217 UT on May 13), an X2.8-class flare (1609 UT on May 13), an X3.2-class flare (0117 UT on May 14), and an X1-class flare (0152 on May 15). The last of these flares was hurled towards Earth and is the reason I was able to capture the massive geomagnetic storm that occurred over the weekend. While green is the most dominant colour of auroras, with stronger storms you're just as likely to find fainter, purple-blue-red colours as well. Today's picture highlights just how bright and elevated the Northern Lights can get even as low as 45.5842° N. In this picture, the auroras fill over 15° of the northern sky in a spectacular array of colours. While pretty to look at, it's also a reminder that the Earth is constantly bombarded by harmful rays of the sun and a very thin layer is all the planet has to protect those rays from entering the planet and disrupting electronics.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 26, 2013

-Mercury, Venus, and Jupiter are bunched their tightest this evening, forming a little triangle just 2° on a side. Look in the northwest 30 or 40 minutes after sunset. Think photo opportunity.

-The best time to view Venus at high power in a telescope is in late afternoon well before sunset, when it's still at a high altitude in relatively steady air. All week Mercury and Jupiter are in the same vicinity, but they're tougher catches in broad daylight.

-Mercury, Venus, and Jupiter are bunched together low in the afterglow of sunset, forming a new configuration each evening. They're magnitudes –1, –4, and –2, respectively. From the 24th through 29th the three form a "trio," fitting in a circle 5° in diameter. They're bunched most tightly, fitting in a 2½° circle, on the evening of the 26th.

-Mercury and Venus appear closest together, just under 1½° apart, on the 23rd and 24th. Venus and Jupiter are closest, 1° apart, on the 28th.

Astro Picture of the Day:
May 26, 2013

Source: My Camera
If you are in a dark location and you are willing to stay up to roughly midnight at this time of year, you have the luxury to step outside on a clear night and enjoy the rise of the milky way - the galaxy that rests in our backyard. Scorpius is the constellation that appears to pull the galactic centre with Antares being the dominant red star in the middle of the constellation. Ophiuchus sits on top of this image above Scorpius, and the Sagittarius Teapot sits above the treeline. Multiple messier objects appear in this image as well including the Trifid and Lagoon nebula.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 27, 2013

-This is the time of year when Spica, the brightest star of Virgo, shines due south just after dark. It's far to the lower right of high, bright Arcturus. Its name means "ear of wheat," and the Virgo stick figure is holding it in her hand without paying much attention. To Spica's lower right (by about a fist and a half at arm's length) is the four-star pattern of Corvus the Crow, eyeing it greedily. This year Corvus has Saturn to try to steal too. Saturn is glowing to Spica's left, noticeably brighter.

-Mercury, Venus, and Jupiter are bunched together low in the afterglow of sunset, forming a new configuration each evening. They're magnitudes –1, –4, and –2, respectively. From the 24th through 29th the three form a "trio," fitting in a circle 5° in diameter. They're bunched most tightly, fitting in a 2½° circle, on the evening of the 26th.

Astro Picture of the Day:
May 27, 2013

Source: My Camera
On May 26, 2013, Mercury, Venus and Jupiter formed a very tight triangle, just 2½° wide. The triple conjunction itself is set to last for a span of a couple weeks where all three planets fit inside a 5° circle, but yesterday was the day where all three were closest together. Venus and Mercury, the two right planets in this image, appear their closest together tomorrow May 28. This image was taken atop Leaside Bridge in Toronto, with a hydrofield in the distance. Jupiter continues to sink lower into the horizon while Venus and Mercury make their way higher into better seeing conditions. Mercury is the fastest changing of the three planets, largely because its year is only 88 days and it does not take very long to revolve around the sun. If you follow Mercury long enough, you will begin to see Mercury arc back downward toward the horizon as it heads for another revolution around the sun.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 28, 2013

-Jupiter and Venus are now at their closest together, 1° apart low in the west-northwest after sunset. Mercury is above them.

-Mercury, Venus, and Jupiter are bunched together low in the afterglow of sunset, forming a new configuration each evening. They're magnitudes –1, –4, and –2, respectively. From the 24th through 29th the three form a "trio," fitting in a circle 5° in diameter. They're bunched most tightly, fitting in a 2½° circle, on the evening of the 26th.

Astro Picture of the Day:
May 28, 2013

Source: My Camera
What does the Andromeda Galaxy look like in a sky with no light pollution? M31 is almost impossible to spot in a city or large town, and to the untrained eye can also be difficult when a bright moon fills the sky. However when there's no moon lighting up the sky, you may begin to notice a sizeable fuzzy patch in the constellation of Andromeda, just beside Perseus. This fuzzy patch is the Andromeda Galaxy. It's approximately 2.5 million light years from Earth, however that number will shrink in time. M31 is on a collision course with the Milky Way that will lead to a head on collision in about 2 billion years. While this sounds violent, it is unlikely in this collision that any stars will actually crash into each other. Familiar stars however, will be thrown out of their current position and hurled to various new spots of the galaxy.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 29, 2013

-Here it is not even June yet, and the Big Dipper after dusk is already turning around to hang down by its handle. Look for it high in the northwest.

-The planet dance is on its way to form a line tonight. Venus and Jupiter are vertically aligned depending on your point of view.

Astro Picture of the Day:
May 29, 2013

Source: My Camera
How bright is nebulosity in Algonquin Park? The answer is its about as bright as it ever gets from the vantage point of this planet. Today's picture is a shot of a pair of nebulae that to my eyes only appeared to be dark fuzzy patches in the sky - I wasn't originally targetting the pair that can be found at the top and bottom of the image but rather I happened to point my camera in this direction while making a larger panorama sized picture. The human eye can't see more than visible light, so many of the nebulae will appear as gray patches. The other reason for this is that they are simply too faint to show colour as well, but a decent camera today will be able to pick them up. A nebula that comes out as a fluorescent violet is likely to have more colour spectra with a wavelength shorter than that of the violet colour spectrum. For this particular nebula, if you had a filter that blocked out all light except ultra Violet, you'd actually get a better picture than one that allows visible light! The following picture highlights the striking difference between infrared, visible and UV filters. Note how the colours of the orion nebula are more vibrant in UV, however the flame nebula near the top left of the image appears invisible in UV - This is because the flame nebula is orange-reddish in colour and is nowhere near the UV spectrum.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 30, 2013

-Vega is the brightest star in the east-northeast these evenings. The main part of its little constellation, Lyra, hangs from it to its lower right.

-The bright planets in these scenes are plain to the naked eye, but the fainter stars may be hard or impossible to see in bright twilight. The scenes are about three fist-widths at arm's length wide. They're drawn for the middle of North America but will be good enough throughout the world's mid-northern latitudes. Today the planet trio forms a line.

Astro Picture of the Day:
May 30, 2013

Source:
The 16th century Portuguese navigator Ferdinand Magellan and his crew had plenty of time to study the southern sky during the first circumnavigation of planet Earth. As a result, two fuzzy cloud-like objects easily visible to southern hemisphere skygazers are known as the Clouds of Magellan, now understood to be satellite galaxies of our much larger, spiral Milky Way galaxy. About 160,000 light-years distant in the constellation Dorado, the Large Magellanic Cloud (LMC) is seen here in a remarkably deep, colorful, and annotated composite image. Spanning about 15,000 light-years or so, it is the most massive of the Milky Way's satellite galaxies and is the home of the closest supernova in modern times, SN 1987A. The prominent patch just left of center is 30 Doradus, also known as the magnificent Tarantula Nebula, is a giant star-forming region about 1,000 light-years across.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 31, 2013

-Mercury, Venus, and Jupiter have stretched out into a nice straight line 7° long. Look low in the northwest after sunset. The line will continue to lengthen day by day, as Jupiter descends to the horizon and Mercury pulls a bit higher above Venus.

-Last-quarter Moon (exact at 2:58 p.m. EDT).

Astro Picture of the Day:
May 31, 2013

Source:
As planet Earth approached the plane of the Comet PanSTARRS (C/2011 L4) orbit on May 23rd, comet watchers were treated to this view of its magnificent anti-tail. The long, narrow anti-tail stretches to the right across this frame for nearly 7 degrees or about 14 times the angular size of the full Moon. Dust forming the anti-tail trails along the comet's orbit as it leaves the inner solar system behind. An almost edge-on perspective from near the outbound comet's orbital plane enhances the view of the anti-tail and makes it seem to point in the sunward direction, only apparently contrary to the behavior of comet dust tails pushed outward by the pressure of sunlight. Sweeping far north in planet Earth's skies, the comet is up all night for most of the northern hemisphere, but now bright moonlight interferes with its visibility. PanSTARRS anti-tail is one of the longest since the appearance of Comet Arend-Roland in 1957.

[Bluearrowll]

Re: Terry's Astronomy Thread.

From Spaceweather.com:

GEOMAGNETIC STORM: A G2-class (Kp=6) geomagnetic storm is in progress following the arrival of an interplanetary shock wave (probably a CME) on May 31st. Solar wind conditions favor auroras at high latitudes.









If you live either on or north of the area of land between Kp = 5 and Kp = 7, congratulations, look north, you may see Auroras!

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
June 1, 2013

-Vega, shining brightly in the east-northeast, it currently the top star of the huge Summer Triangle. Look to Vega's lower left, by two or three fists at arm's length, for Deneb. The third star of the Summer Triangle is Altair, considerably farther to Vega's lower right. Altair is barely rising in the east as dusk fades away this week. How early in the evening can you spot it?

-At this time of year, right as the stars come out, the bright constellation Cassiopeia is directly underneath Polaris.

Astro Picture of the Day:
June 1, 2013

Source:
Last night, a powerful interplanetary shockwave from the sun slammed the planet and resulted in a G2-class (Kp=6) geomagnetic storm. The storm as of this post still has not let up, but at its peak from last night, it was easily visible as far south as Colorado, Maryland, Iowa, Wisconsin, and Nebraska. High-latitude sky watchers should remain alert for auroras tonight as Earth's magnetic field continues to reverberate from the impact. Today's photograph was taken by Bob Conzemius on June 1, 2013 at Grand Rapids, MN, USA. The powerful green auroras were luminescent enough to penetrate through a thin layer of clouds and create an eerie green skyscape, complemented by the yellow lights of nearby towns. ISO 800, f2.8, 25 sec., 24mm, looking east along the cloud-obscured oval was the specifications for this photo.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
June 2, 2013

-The best time to view Venus in a telescope is in late afternoon well before sunset, when it's still at a high altitude in relatively steady air. Mercury and Jupiter are in the same vicinity, but they're tougher catches in broad daylight.

-Mercury, Venus, and Jupiter are still visible in the afterglow of sunset, forming a straight line pointing downward just above the west-northwest horizon as shown at the top of this page. Venus is the brightest. Jupiter, the bottom one, becomes harder to see each day and is gone by the end of the week. Mercury on top is having its best evening appearance of 2013.

Astro Picture of the Day:
June 2, 2013

Source:
What kind of cloud is this? A roll cloud. These rare long clouds may form near advancing cold fronts. In particular, a downdraft from an advancing storm front can cause moist warm air to rise, cool below its dew point, and so form a cloud. When this happens uniformly along an extended front, a roll cloud may form. Roll clouds may actually have air circulating along the long horizontal axis of the cloud. A roll cloud is not thought to be able to morph into a tornado. Unlike a similar shelf cloud, a roll cloud, a type of Arcus cloud, is completely detached from their parent cumulonimbus cloud. Pictured above, a roll cloud extends far into the distance in 2009 January above Las Olas Beach in Maldonado, Uruguay.