Terry's Astronomy Thread.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
September 18, 2013

-Full Moon tonight and tomorrow night (exactly full at 7:13 a.m. Thursday morning EDT). The Moon is passing through dim Pisces, to the lower right of the Great Square of Pegasus both evenings.

-Tonight's full Moon is the "Harvest Moon," the full Moon closest to the autumnal equinox. Look for it rising in the east at sunset. Swollen by the Moon illusion and reddened by the effect of low-hanging clouds, the rising Harvest moon is often likened to a "Great Pumpkin."

-After a week of deep quiet, the drowsy sun seems to be waking up. Five new sunspots were numbered on Sept. 17th as the sun hurled a series of coronal mass ejections (CMEs) into space. The Solar and Heliospheric Observatory recorded the expanding clouds. Earth was not in the line of fire of the CMEs. One of them, however, might deliver a glancing blow to our planet's magnetic field a few days hence.

Astro Picture of the Day:
September 18, 2013

Source:
Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as dusty as this. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen without binoculars from even the depths of a light-polluted city. With a long exposure from a dark location, though, the dust cloud surrounding the Pleiades star cluster becomes very evident. The above exposure took about 30 hours and covers a sky area several times the size of the full moon. Also known as the Seven Sisters and M45, the Pleiades lies about 400 light years away toward the constellation of the Bull (Taurus). A common legend with a modern twist is that one of the brighter stars faded since the cluster was named, leaving only six stars visible to the unaided eye. The actual number of Pleiades stars visible, however, may be more or less than seven, depending on the darkness of the surrounding sky and the clarity of the observer's eyesight.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
September 19, 2013

-A winter preview: If you're up before dawn this week, the southern sky displays the same starry panorama as it will at dusk next February. Orion stands high in the south, Sirius and Canis Major sparkle to its lower left, and Gemini, with Jupiter, occupies the high east. Come February, Jupiter will still be there.

-Comet ISON is still more than two months away from its spectacular close encounter with the sun. Amateur astronomers aren't waiting. Observers of Comet ISON will notice that it is in the same part of the sky as Mars. The comet will make a close approach to the Red Planet on October 1st, and during that time Mars satellites will be taking ISON's picture at point blank range. Those images will likely rival or improve upon the view from Earth. Comet ISON is currently not a naked eye object, but Up to date pictures of Comet ISON can be found here: http://spaceweather.com/gallery/inde...et&title2=ison

Astro Picture of the Day:
September 19, 2013

Source:
In this engaging scene from planet Earth, the Moon shines through cloudy skies following sunset on the evening of September 8. Despite the fading light, the camera's long exposure still recorded a colorful, detailed view of a shoreline and western horizon looking toward the island San Gabriel from Colonia del Sacramento, Uruguay. Lights from Buenos Aires, Argentina are along the horizon on the left, across the broad Rio de la Plata estuary. The long exposure strongly overexposed the Moon and sky around it, though. So the photographer quickly snapped a shorter one to merge with the first image in the area around the bright lunar disk. As the the second image was made with a telephoto setting, the digital merger captures both Earth and sky, exaggerating the young Moon's slender crescent shape in relation to the two nearby bright stars. The more distant is bluish Spica, alpha star of the constellation Virgo. Closest to the Moon is Earth's evening star, planet Venus, emerging from a lunar occultation.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Saturn is still 4° to the upper right of bright Venus in twilight, as shown here. Watch it move farther from Venus each evening.

-As summer nears its end, orange Antares blinks its bleary seasonal farewell low in the southwest after dusk. The farther north you are, the sooner Antares sinks out of sight.

Astro Picture of the Day:
September 20, 2013

Source:
Colorful stars trail through this late summer, night skyscape from Cape Cod, Massachusetts. The picture was composed by stacking 12 consecutive 1 minute long digital camera exposures to follow the trails, a reflection of our fair planet's daily rotation. It also records faint clouds of the Milky Way in the clear sky, stretching above a local drive-in movie theater. In fact, watching movies from cars at the drive-in was once a more common night time activity. But while the stars still shine, drive-in theaters have faded from the American landscape over the decades since the 1950s. Still, this recent scene includes a short exposure made as the projector beamed a space age image to the movie screen, and drive-in skygazers watched a view of the Earth below the International Space Station, under the stars above.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-After the last of twilight has faded away, the Northern Cross in Cygnus floats near the zenith (for skywatchers at mid-northern latitudes). Without looking: Do you know which way its long end points? If you guessed southwest, you're right.

-The September equinox occurs at 4:44 p.m. EDT (20:44 UT) on Sunday, Sept. 22nd, when the Sun crosses the equator heading south. This marks the beginning of autumn in the northern hemisphere and spring in the southern hemisphere. On this date, day and night are of approximately equal length.

You know the equinox is near when you find yourself nearly-blinded while driving down east-west roads. Alan Friedman demonstrates the phenomenon from his hometown in Buffalo, New York. "At the equinoxes, the sun rises due east and sets due west on my street in Buffalo," says Friedman. "One has to drive carefully!"

Astro Picture of the Day:
September 21, 2013

Source:
The sky looks dark in this scene from the Mid-Atlantic Regional Spaceport (MARS) at NASA Wallops Flight Facility, Virginia. Captured on Wednesday, September 18, an Orbital Sciences Corporation Antares rocket is leaving launch pad-0A with the Cygnus cargo spacecraft aboard. Though it looks like night, the photograph was taken at 10:58am EDT, under bright, clear morning skies, with a digital camera modified to record infrared images. The Sun itself is above and left of the picture frame, creating strong glare and internal reflections in the camera lens at near-infrared wavelengths. In the false-color presentation, the vegetation and watery reflections also take on an otherworldly pallor. Reaching orbit, the Cygnus spacecraft is now on its way to a Sunday rendezvous with the International Space Station. The spacecraft will deliver about 1,300 pounds (589 kilograms) of cargo to the Expedition 37 crew.

[Riotpolice]

Re: Terry's Astronomy Thread.

Last night and the night before we watched the Harvest Moon. Boy was it bright!!

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-The September equinox occurs at 4:44 p.m. EDT today, when the Sun crosses the equator heading south for the season. Fall begins in the Northern Hemisphere, spring in the Southern Hemisphere.

-As summer ends, the Sagittarius Teapot moves to the west of south during evening and tips increasingly far over, as if pouring out summer's last drops.

-NASA's Solar Dynamics Observatory is monitoring a coronal hole in the sun's northern hemisphere. It is the UV-dark region in this image taken during the early hours of Sept. 21st. The white lines in the image trace the sun's magnetic field. A coronal hole is a place where the magnetic field spreads apart, allowing solar wind to escape. A stream of solar wind flowing from this particular coronal hole is heading for Earth, due to arrive on Sept. 23-24. Its arrival could add to the impact of a minor CME expected to reach Earth at about the same time. Polar geomagnetic storms are possible early next week.

Astro Picture of the Day:
September 22, 2013

Source:
Today, the Sun crosses the celestial equator heading south at 20:44 Universal Time. An equinox (equal night), this astronomical event marks the first day of autumn in the northern hemisphere and spring in the south. With the Sun on the celestial equator, Earth dwellers will experience nearly 12 hours of daylight and 12 hours of darkness. To celebrate, consider this remarkable record of the Sun's yearly journey through planet Earth's sky, made with planned multiple exposures captured on a single piece of 35 millimeter film. Exposures were made at the same time of day (9:00am local time), capturing the Sun's position on dates from January 7 through December 20, 2003. The multiple suns trace an intersecting curve known as an analemma. A foreground base exposure of the Temple of Apollo in ancient Corinth, Greece, appropriate for an analemma, was digitally merged with the film image. Equinox dates correspond to the middle points (not the intersection point) of the analemma. The curve is oriented at the corresponding direction and altitude for the temple, so the Sun's position for the September equinox is at the upper midpoint near picture center. Summer and winter solstices are at analemma top and bottom.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Altair shines due south very high after dark. It's the leading light of the constellation Aquila, the Eagle. Off the tail of Aquila lies the Scutum Star Cloud, with the grand open cluster M11 just below the dark nebula Barnard 111.

-Comet ISON is falling toward the sun for a close encounter on Thanksgiving Day 2013. If it survives, it could become one of the finest comets in years. At the moment ISON is still far away and faint, but its sunward velocity is impressive--more than 72,000 mph on Sept. 22nd.

Alberto Quijano Vodniza of Pasto, Narino, Colombia, obtained the 35-minute video on Sept 22nd. "The motion of the comet was clearly visible," he says. "I used a 14-inch Celestron telescope and a STL-1001E SBIG camera." The video can be found here: http://spaceweather.com/gallery/indi...pload_id=86998

Comet ISON is now approaching Mars in the eastern sky before sunrise. On Oct. 1st it will fly past the Red Planet at a distance on only 0.07 AU. Mars satellites and rovers are in position to snap the first close-up pictures of the comet.

News Posted Today:
September 23, 2013
Is Phaethon a "Rock Comet"?


Astro Picture of the Day:
September 23, 2013

Source:
South of Antares, in the tail of the nebula-rich constellation Scorpius, lies emission nebula IC 4628. Nearby hot, massive stars, millions of years young, radiate the nebula with invisible ultraviolet light, stripping electrons from atoms. The electrons eventually recombine with the atoms to produce the visible nebular glow, dominated by the red emission of hydrogen. At an estimated distance of 6,000 light-years, the region shown is about 250 light-years across, spanning an area equivalent to four full moons on the sky. The nebula is also cataloged as Gum 56 for Australian astronomer Colin Stanley Gum, but seafood-loving astronomers might know this cosmic cloud as The Prawn Nebula.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Mercury and Spica are in conjunction just 3/4° apart, very low in the west-southwest in bright twilight. About 20 minutes after sunset, use binoculars to look for them 22° to the lower right of Venus. Mercury is magnitude –0.1. Spica is only a third as bright at magnitude +1.0.

-Today is another day that seems more like Solar Min than Solar Max. All of the sunspots on the Earthside of the sun are quiet, and solar activity is low. NOAA forecasters estimate a slim 5% chance of M-class flares on Sept. 24th.

Astro Picture of the Day:
September 24, 2013

Source:
The stars are not alone. In the disk of our Milky Way Galaxy about 10 percent of visible matter is in the form of gas, called the interstellar medium (ISM). The ISM is not uniform, and shows patchiness even near our Sun. It can be quite difficult to detect the local ISM because it is so tenuous and emits so little light. This mostly hydrogen gas, however, absorbs some very specific colors that can be detected in the light of the nearest stars. A working map of the local ISM within 20 light-years, based on ongoing observations and recent particle detections from the Earth-orbiting Interstellar Boundary Exporer satellite (IBEX), is shown above. These observations indicate that our Sun is moving through a Local Interstellar Cloud as this cloud flows outwards from the Scorpius-Centaurus Association star forming region. Our Sun may exit the Local Cloud, also called the Local Fluff, during the next 10,000 years. Much remains unknown about the local ISM, including details of its distribution, its origin, and how it affects the Sun and the Earth. Unexpectedly, recent IBEX spacecraft measurements indicate that the direction from which neutral interstellar particles flow through our Solar System is changing.

[top]

Re: Terry's Astronomy Thread.

check this thread every day. still awesome as hell. never stop!

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-The Moon rises late this evening (around 11 p.m. depending on your location), with Aldebaran well to its upper right and brighter Capella farther to its upper left. Earlier, spot these two stars when they're low to judge where the Moon will rise.

-Near the center of the solar disk, growing sunspot AR1850 directly faces Earth. However, like all the other spots on the sun today, AR1850 is quiet and not flaring. The chance of a geoeffective flare today is low.

-Amateur astronomers around the world are photographing Comet ISON as it approaches Mars in the predawn sky. The comet is not as bright as some forecasters expected. What does that mean for ISON's future prospects? The answer may be found below this color photo of the comet obtained by UK astronomer Damian Peach on Sept. 24th. At the moment, Comet ISON is about as bright as a 14th magnitude star, which puts it one or two magnitudes dimmer than forecasts. Nevertheless, according to several experts speaking in a NASA video, Comet ISON is still on track to become an impressive sungrazer. John Bortle predicts ISON will rival Venus during the hours leading up to its closest approach to the Sun in November, while Matthew Knight notes that Comet ISON is brighter than Comet Lovejoy was at the same distance from the sun in 2011. Comet Lovejoy went on to become a spectacular naked-eye object. Comet ISON might do the same. The second comet below is a picture of Comet Lovejoy at its peak, which was only visible to the Southern Hemisphere.

Astro Picture of the Day:
September 25, 2013

Source:
Here in the Milky Way galaxy we have astronomical front row seats as M81 and M82 face-off, a mere 12 million light-years away. Locked in a gravitational struggle for the past billion years or so, the two bright galaxies are captured in this deep telescopic snapshot, constructed from 25 hours of image data. Their most recent close encounter likely resulted in the enhanced spiral arms of M81 (left) and violent star forming regions in M82 so energetic the galaxy glows in X-rays. After repeated passes, in a few billion years only one galaxy will remain. From our perspective, this cosmic moment is seen through a foreground veil of the Milky Way's stars and clouds of dust. Faintly reflecting the foreground starlight, the pervasive dust clouds are relatively unexplored galactic cirrus, or integrated flux nebulae, only a few hundred light-years above the plane of the Milky Way.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Last-quarter Moon tonight (exact at 11:55 p.m. EDT). The Moon rises around 11 or midnight local time, shining in the feet of Gemini. Jupiter is to its lower left, as shown below, and Orion is farther to its right.

-A filament of magnetism curling over the sun's northeastern limb erupted on Sept. 24th around 20:30 UT. NASA's Solar Dynamics Observatory caught the structure hurling part of itself into space. A "canyon of fire" forms as the filament cuts through the sun's lower atmosphere. The glowing walls of the canyon trace the original channel where the filament was suspended by magnetic forces above the stellar surface.

-As erupting magnetic filaments often do, this one launched a coronal mass ejection (CME) into space. The cloud does not appear to be heading for Earth.

Astro Picture of the Day:
September 26, 2013

Source:
Separated by about 14 degrees (28 Full Moons) in planet Earth's sky, spiral galaxies M31 ,left, and M33 are both large members of the Local Group, along with our own Milky Way galaxy. This wide-angle, telescopic mosaic captures colorful details of spiral structure in both, while the massive neighboring galaxies seem to be balanced either side of bright Mirach, beta star in the constellation Andromeda. But M31, the Andromeda Galaxy, is really 2.5 million light-years distant and M33, the Triangulum Galaxy, is also about 3 million light years away. Mirach, just 200 light-years from the Sun, lies well within the Milky Way, along with the dim clouds of dust drifting through the frame only a few hundred light-years above the galactic plane. Although they look far apart, M31 and M33 are locked in a mutual gravitational embrace. Radio astronomers have found indications of a bridge of neutral hydrogen gas that could connect the two, evidence of a closer encounter in the past. Based on measurements, gravitational simulations currently predict that the Milky Way, M31, and M33 will all undergo mutual close encounters and potentially mergers, billions of years in the future.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-The Moon, a day past last quarter, rises by 1 a.m. tonight (Saturday morning the 28th), with Jupiter shining to its upper left as shown here. Can you spot Delta Geminorum, magnitude 3.6, just ½° below Jupiter?

-For reasons reseachers don't fully understand, auroras love equinoxes. At this time of year, even small gusts of solar wind can spark colorful lights around the poles. On Thursday, the aurora australis appeared over South Arm, Tasmania.

"I captured this image from Betsey Island," says photographer Luke O'Brien. "This is a 30 second exposure at ISO 2500. "

The solar wind blowing past Earth today is relatively slow, only ~350 km/s. As a result, NOAA forecasters estimate a slim 5% chance of polar geomagnetic storms. That might be enough, however, for more equinox auroras.

-The weakest Solar Max in 100 years continues today with another 24 hours of quiet. None of the sunspots on the Earthside of the sun are actively flaring.

Astro Picture of the Day:
September 27, 2013

Source:
How far can you see? The Andromeda Galaxy 2.5 million light years away is the most distant object easily seen by the unaided eye. Other apparent denizens of the night sky, stars, clusters, and nebulae, typically range from a few hundred to a few thousand light-years away and lie well within our own Milky Way Galaxy. Also known as M31, the Andromeda Galaxy is the faint smudge near top center of this Earth and skyscape, taken from eastern Italy, near Monte Conero on the Adriatic sea coast. From a few centimeters to a few million light-years, the picture demonstrates a stunning range of vision. Though galaxy and seaside rocks could be seen with the eye on that clear summer night, no camera captured this view in a single exposure. Because the stars trailed above the horizon while the picture was made, separate exposures tracking the stars were combined with one of rocks and cliffs made with the camera steadied to create the tantalizing scene.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-This is the time of year when, in mid-evening, W-shaped Cassiopeia stands on end halfway up the northeastern sky. And whenever that happens, the dim Little Dipper extends straight leftward from Polaris due north.

-On Sept. 25th, China's experimental Tiangong-1 space station passed directly in front of the sun over Arizona. Mike Weasner held his iPhone 5s up to the eyepiece of a solar-filtered 8" telescope and captured this picture of the spit-second transit.

"The Tiangong-1 space station is about 10 meters by 3 meters in size and was 510.4 kilometers from my observatory at the time of the transit," says Weasner. "The angular diameter of the station was only 4.4 arcsec. Yes, that's small!"

Weasner used CalSky to predict the moment of transit. "I began slo-mo video recording with the iOS 7 Camera app on the iPhone 5s at 095015 MST and continued it for one minute to ensure that I captured the space station," he says. "The Tiangong-1 was successfully imaged on several frames as it crossed the sun's disk."

Most readers are familiar with the 450-ton International Space Station. Fewer may be aware of China's 8.5-ton Tiangong-1 (Heavenly Palace-1). It was launched in Sept. 2011 to establish a foothold in Earth orbit for China's fledgling space program. Since then taikonauts (Chinese astronauts) have visited the Tiangong-1 to practice rendevous and docking procedures and to train for living in space. According to some reports, the Tiangong-1 will be de-orbited in late 2013 to make way for more advanced experimental stations, Tiangong-2 and Tiangong-3 in the years ahead. Ultimately, China hopes to place an Mir-class station in orbit by 2020.

Astro Picture of the Day:
September 28, 2013

Source:
From a geostationary orbit 36,000 kilometers above the equator, Russian meteorological satellite Elektro-L takes high-resolution images our fair planet every 30 minutes. But only twice a year, during an Equinox, can it capture an image like this one, showing an entire hemisphere bathed in sunlight. At an Equinox, the Earth's axis of rotation is not tilted toward or away from the Sun, so the solar illumination can extend to both the planet's poles. Of course, this Elektro-L picture was recorded on September 22nd, at the northern hemisphere's autumnal equinox. For a moment on that date, the Sun was behind the geostationary satellite and a telltale glint of reflected sunlight is seen crossing the equator, at the location on the planet with satellite and sun directly overhead. This gif is shown below.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Watch a Rocket Launch at 12:00PM EST: http://www.spacex.com/webcast/

With the launch of the hybrid small satellite CASSIOPE, scheduled for 2013, Canada will make a significant contribution to unraveling the mysteries of space weather. To accomplish this feat, the satellite will use a dedicated scientific payload ePOP (enhanced polar outflow probe), which will observe the ionosphere.

-Arcturus is shining ever lower in the west after dusk as autumn proceeds. Some time around 9 p.m., depending on how far east or west you live in your time zone, Arcturus sinks to the same altitude in the west as Capella has risen to in the northeast. How accurately can you time this event? It happens 4 minutes earlier each day.

Astro Picture of the Day:
September 29, 2013

Source:
The dust sculptures of the Eagle Nebula are evaporating. As powerful starlight whittles away these cool cosmic mountains, the statuesque pillars that remain might be imagined as mythical beasts. Pictured above is one of several striking dust pillars of the Eagle Nebula that might be described as a gigantic alien fairy. This fairy, however, is ten light years tall and spews radiation much hotter than common fire. The greater Eagle Nebula, M16, is actually a giant evaporating shell of gas and dust inside of which is a growing cavity filled with a spectacular stellar nursery currently forming an open cluster of stars. The above image in scientifically re-assigned colors was released in 2005 as part of the fifteenth anniversary celebration of the launch of the Hubble Space Telescope.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-In the eastern dawn Tuesday morning, look for the thin waning crescent Moon forming a triangle with Mars and Regulus, as shown below. Best view: at least an hour before your local sunrise.

-On Sept. 27th, a meteor exploded in the skies above the US midwest. Witnesses report shadows cast upon the ground, unusual sounds, and a swirling contrail marking the aftermath of the blast. "It was the most brilliant fireball that I have ever seen!" reports Angela McClain, who sends this picture from Faith Ranch in Jewett, Ohio.

"The entire landscape lit up," she continues. "I spun around and there it was, a huge, bright green light, streaking across the sky. Even when it was gone, there was still a bright line in the sky about 20 seconds later. We were all stunned."

"This was a very bright event," says Bill Cooke of NASA's Meteoroid Environment Office. "Flares saturated our meteor cameras, and made determination of the end point (the terminus of the fireball's flight through the atmosphere) virtually impossible. Judging from the brightness, we are dealing with a meter class object."

Data from multiple cameras shows that the meteoroid hit Earth's atmosphere traveling 51 km/s (114,000 mph) and passed almost directly over Columbus, Ohio. Cooke has prepared a preliminary map of the ground track. According to the American Meteor Society, the fireball was visible from at least 14 US states.

Astro Picture of the Day:
September 30, 2013

Source:
What is it? Some surely natural phenomenon has appeared in a video that, so far, has defied clear identification. The above time-lapse video was made to record Perseid meteors above Hopewell Rocks in New Brunswick, Canada late this summer. The video, which ran from 9:30 pm August 11 to 3:00 am the next morning, records several meteor and satellite streaks beyond a picturesque background. Each image records a 30 second exposure. At about 25 seconds into the video, however, an unusual patchy green glow appears to cover the sky. Possible explanations include airglow, aurora, lighting from an artificial or natural source, or something completely different.