From Hubble: a grand new view of M9

Photo: M9 globular star cluster. Hubble image by NASA & ESA.
The stars of the M9 globular cluster. Photo credit: NASA & ESA.

The NASA/ESA Hubble Space Telescope has produced the most detailed image so far of Messier 9 (M9), a globular star cluster located close to the center of the galaxy. This ball of stars is too faint to see with the naked eye, yet Hubble can see over 250,000 individual stars shining in it.

M9, pictured here is a roughly spherical swarm of stars that lies around 25,000 light-years from Earth, near the center of the Milky Way, so close that the gravitational forces from the galactic center pull it slightly out of shape. Globular clusters are thought to harbor some of the oldest stars in our galaxy, born when the Universe was just a small fraction of its current age. As well as being far older than the Sun —around twice its age— the stars of M9 also have a markedly different composition, and are enriched with far fewer heavier elements than the Sun.

In particular, the elements crucial to life on Earth, like oxygen and carbon, and the iron that makes up our planet’s core, are very scarce in M9 and clusters like it. This is because the Universe’s heavier elements were gradually formed in the cores of stars, and in supernova explosions. When the stars of M9 formed, there were far smaller quantities of these elements in existence.

M9, as its name suggests, was discovered by the great French comet hunter Charles Messier in 1764. Even through the most advanced telescopes of the day, none of the stars in the cluster could be seen individually. Messier, seeing only a faint smudge, therefore classified the object as a nebula –or “cloud” in Latin– and put it on his list of objects that looked like but were not comets. It was only later in the 18th century that astronomers, most notably William Herschel, began to spot stars within the cluster.

The contrast between Messier’s equipment and the tools at the disposal of today’s astronomers is stark. Hubble’s image, the highest resolution image yet made of M9, is able to resolve individual stars, right into the crowded center of the cluster. Over 250,000 of them are neatly focused on the detector of Hubble’s Advanced Camera for Surveys, in an image which covers an area of sky no bigger than the size of the head of a pin held at arm’s length.

As well as showing the individual stars, Hubble’s image clearly shows the different colors of the stars. A star’s color is directly related to its temperature — counter-intuitively, perhaps, the redder it is, the cooler it is; and the bluer it is, the hotter. The wide range of stellar temperatures here is clearly displayed by the broad palette of colors visible in Hubble’s image of M9.

Planets and moon(s) grace our evening sky

Photo: Moon and Jupiter by James Guilford
Earth's Moon and planet Jupiter form the base of a tall triangle. Photo by James Guilford.

Tonight, and for the next couple of nights, Earth’s Moon joins this spring’s conjunction of Jupiter and Venus in our western evening sky. The clouds cleared just in time for the show and I stepped outdoors, tripod-mounted camera in hand, to record the sight as best I could. The three objects, on the list of brightest in the night sky, formed a very elongated triangle with Jupiter and the Moon forming the base, and brilliant Venus at the peak (not shown in the photo above). The three were visible in bright twilight but really came into their own around 8:30 EDT. Later, as I processed my photos, I was surprised and delighted to see I had captured not only Venus, Jupiter, and the Moon but, in a tighter shot, a couple of Jupiter’s moons as well! The nighttime portion of the Moon’s face is lit by Earthshine. Canon EOS 50D: ISO 800, f/4, 1/4 sec., 200mm — James Guilford, 8:34 PM EDT, March 25, 2012

Finding bubbles in the Milky Way

Photo: Stellar bubbles detected by people! Image credit: NASA/JPL-Caltech/Oxford University
Image credit: NASA/JPL-Caltech/Oxford University

A team of volunteers from the general public has pored over observations from NASA’s Spitzer Space Telescope and discovered more than 5,000 “bubbles” in the disk of our Milky Way galaxy. Young, hot stars blow the bubbles into surrounding gas and dust, highlighting areas of brand new star formation.

Upwards of 35,000 “citizen scientists” sifted through the Spitzer infrared data as part of the online Milky Way Project to find these telltale bubbles. The users have turned up 10 times as many bubbles as previous surveys so far.

Computer programs struggle at identifying the cosmic bubbles. But human eyes and minds do an excellent job of noticing the wispy arcs of partially broken rings and the circles-within-circles of overlapping bubbles. The Milky Way Project taps into the “wisdom of crowds” by requiring that at least five users flag a potential bubble before its inclusion in the new catalog. Volunteers mark any candidate bubbles in the infrared Spitzer images with a sophisticated drawing tool before proceeding to scour another image.

“The Milky Way Project is an attempt to take the vast and beautiful data from Spitzer and make extracting the information a fun, online, public endeavor,” said Robert Simpson, a postdoctoral researcher in astronomy at Oxford University, England, principal investigator of the Milky Way Project and lead author of the paper.

The data come from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) and Multiband Imaging Photometer for Spitzer Galactic (MIPSGAL) surveys. These datasets cover a narrow, wide strip of the sky measuring 130 degrees wide and just two degrees tall. From a stargazer’s perspective, a two-degree strip is about the width of your index finger held at arm’s length, and your arms opened to the sky span about 130 degrees. The surveys peer through the Milky Way’s disk and right into the galaxy’s heart.

Volunteers for the project are shown a small section of Spitzer’s huge infrared Milky Way image (left), which they then scan for cosmic bubbles. Using a sophisticated drawing tool, the volunteers trace the shape and thickness of the bubbles.

All the user drawings can be overlaid on top of one another to form a so-called “heat map” (middle). Features that have been identified repeatedly by many different users jump out, revealing the overall pattern of bubbles in this part of the galaxy.

At least five volunteers must flag a candidate bubble before it is included in the final catalog (right). The brightness of each bubble in the catalog is determined by its “hit rate,” or the fraction of users who traced it out. The faintest ones were identified by 10 percent of the users, while solid white indicates a hit rate of 50 percent or better.

After identifying all apparent bubbles, which can include wispy arcs of partially broken rings and the circles-within-circles of overlapping bubbles, volunteers get another of the 12,263 possible image sections to scrutinize. With so much sky to cover, it is clear why so many volunteers are needed to do this kind of science.



Image credit: NASA/JPL-Caltech/Oxford University

Deaths: Ray A. Paul

We are sorry to report the passing of Ray A. Paul, husband of past CAA president Lynn (Laux) Paul. We offer our condolences to Lynn and her family and friends. Ray was active in amateur astronomy in Cleveland and in Akron, where he served as observatory director of the astronomy club of Akron. Ray and Lynn were very active amateur astronomers and experienced astro-photographers. They enjoyed trips together out West for stargazing and photography.

Ray, age 65, was a U.S. Army Vietnam veteran and Bronze Star recipient. Services were held at St. Peter and Paul Church in Doylestown, OH. Burial was in the Ohio Western Reserve National Cemetery.

The following obituary was published in The Cleveland Plain Dealer on March 5, 2012:

PAUL RAY A. PAUL, age 65. Beloved husband of Lynn (nee Kuhel). Loving father of Ryan Paul, Katherine Laux and Christopher Laux. Dearest son of Claire (nee Trunk) and the late Stanley Paul. Dear brother of Anita Stanners (Bob), Elaine Paul-Muelas, Jeff Paul (Linda) and Robert Paul (Tina). Dear son in law of Jim and Irene Kuhel. Also survived by aunts, uncle, nieces, nephews, great nephews, cousins and many dear friends. U.S. Army Vietnam Veteran and Bronze Star recipient. Member of Cuyahoga Astronomical Association and former observatory director of the astronomy club of Akron. Mass of Christian Burial Wednesday March 7, 2012 St. Peter & Paul Church, 161 W. Clinton St., Doylestown, Ohio at 11:00 AM. Final Resting Place Ohio Western Reserve National Cemetery. Arrangements entrusted to the A. RIPEPI & SONS FUNERAL HOME, 18149 BAGLEY ROAD, MIDDLEBURG HEIGHTS, OHIO 44130, 440-260-8800 (WEST OF I-71).

The Earth is also a planet: A Big Blue Marble

Photo Credit: NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring
Big Image from New Satellite Captures Amazing Detail

A ‘Blue Marble’ image of the Earth taken from the VIIRS instrument aboard NASA’s most recently launched Earth-observing satellite – Suomi NPP. This composite image uses a number of swaths of the Earth’s surface taken on January 4, 2012. The NPP satellite was renamed ‘Suomi NPP’ on January 24, 2012 to honor the late Verner E. Suomi of the University of Wisconsin.

Suomi NPP is NASA’s next Earth-observing research satellite. It is the first of a new generation of satellites that will observe many facets of our changing Earth. Suomi NPP is carrying five instruments on board. The biggest and most important instrument is The Visible/Infrared Imager Radiometer Suite or VIIRS.

Various sizes of this awe-inspiring image are available through NASA’s Flickr site including the astonishingly big 8,000 X 8,000-pixel original size! Be warned… it may be too much for your browser to handle!

Credit: NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring

Star clears away birth clouds

Photo: Hubble Space Telescope image of star-forming region Sh 2-106, or S106 for short.
Image credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA)

The Hubble Space Telescope’s Wide Field Camera-3 has captured this image of a giant cloud of hydrogen gas illuminated by a bright young star. The image shows how violent the end stages of the star-formation process can be, with the young object shaking up its stellar nursery. Click here for a much larger image!

Despite the celestial colors of this picture, there is nothing peaceful about star forming region Sh 2-106, or S106 for short. A devilish young star, named S106 IR, lies in it and ejects material at high speed, which disrupts the gas and dust around it. The star has a mass about 15 times that of the Sun and is in the final stages of its formation. It will soon quieten down by entering the main sequence, the adult stage of stellar life.

For now, S106 IR remains embedded in its parent cloud, but it is rebelling against it. The material spewing off the star not only gives the cloud its hourglass shape but also makes the hydrogen gas in it very hot and turbulent. The resulting intricate patterns are clearly visible in this Hubble image.

The young star also heats up the surrounding gas, making it reach temperatures of 10 000 degrees Celsius. The star’s radiation ionizes the hydrogen lobes, making them glow. The light from this glowing gas is colored blue in this image.

Separating these regions of glowing gas is a cooler, thick lane of dust, appearing red in the image. This dark material almost completely hides the ionizing star from view, but the young object can still be seen peeking through the widest part of the dust lane.

S106 was the 106th object to be cataloged by the astronomer Stewart Sharpless in the 1950s. It is a few thousand light-years distant in the direction of Cygnus (The Swan). The cloud itself is relatively small by the standards of star-forming regions, around 2 light-years along its longest axis. This is about half the distance between the Sun and Proxima Centauri, our nearest stellar neighbor.

This composite picture was obtained with the Wide Field Camera 3 on the NASA/ESA Hubble Space Telescope. It results from the combination of two images taken in infrared light and one which is tuned to a specific wavelength of visible light emitted by excited hydrogen gas, known as H-alpha. This choice of wavelengths is ideal for targeting star-forming regions. The H-alpha filter isolates the light emitted from hydrogen in gas clouds while the infrared light can shine through the dust that often obscures these regions.

Pillars of the Sun

Photo: Brilliant sky with a sun pillar rising over trees. Photo by James Guilford.
A sun pillar rises into a firey December morning sky.

In the mornings and evenings of the cold seasons we are occasionally favored with glorious sunrises and sunsets. A few of those beautiful moments boast something beyond colored clouds and sky; they host sun pillars! Unknown Object

Sun pillars are the result of low-angle sunlight reflected from flat plate-shaped ice crystals suspended high in the air. Pillars can extend from approximately where the Sun sits, near the horizon, to points straight up and high above.

Monday morning, December 13, presented one of those fleeting moments as I drove to the office. I hurriedly pulled into a parking lot, extracted my camera from its case, and shot a few photos of the beautiful sky. A few minutes later, with the Sun slightly higher and the clouds slightly heavier, the fiery colors had faded and the sun pillar was gone.

Pillars, such as I saw, can also occur at night in the colder months. Lights from streetlamps, parking lots, buildings, and so forth can be reflected by atmospheric ice and produce delicately beautiful light pillars that are often mistaken for auroras.

So as you start or end your day, take the occasional glance at the sky. Perhaps you, too, will see the pillars of the Sun!