What’s Up this Week: October 1 – October 7, 2007

Monday, October 1 – In 1897, the world’s largest refractor (40″) debuted at the dedication of the University of Chicago’s Yerkes Observatory. The immense telescope was 64 feet long and weighed 6 tons. Also today in 1958, NASA was established by an act of Congress. More? In 1962, the 300 foot radio telescope of the National Radio Astronomy Observatory (NRAO) went live at Green Bank, West Virginia. It held its place as the world’s second largest radio scope until it collapsed in 1988. (It was rebuilt as a 100 meter dish in 2000.)

Although first light for the 40″ was Jupiter, E. E. Barnard later discovered the third companion star to Vega using the Yerkes refractor. First “light” studies at Green Bank were a radio source galaxy and pulsar for NRAO. Tonight we’re going to turn our attention toward Pegasus and the incredible M15. Although we don’t have that much aperture to study with tonight, we can still get a very satisfactory look at M15 through any size binoculars or telescope.

You can find it easily just about two fingerwidths northwest of red Epsilon Pegasi (Enif). Shining brightly at magnitude 6.4, low power users will find it a delightfully tight ball of stars, but scope users will find it quite unique. As resolution begins, sharp-eyed observers will note the presence of a planetary nebula – Pease 1. This famous X-ray source you have just seen with your eyes may have supernovae remnants buried deep inside…

Tuesday, October 2 – If you’re up before dawn this morning, take a look at the Moon. You’ll find the “Red Planet” – Mars – less than a fistwidth south!

Tonight’s destination is not an easy one, but if you have a 6″ or larger scope, you’ll fall in love at first sight! Let’s head for Eta Pegasi and slightly more than four degrees north-northeast for NGC 7331.

This beautiful, 10th magnitude, tilted spiral galaxy is very much how our own Milky Way would appear if we could travel 50 million light-years away and look back. Very similar in structure to both our own Milky Way and the Great Andromeda Galaxy, this particular galaxy gains more and more interest as scope size increases – yet it can be spotted with larger binoculars. At around 8″ in aperture, a bright core appears and the beginnings of wispy arms. In the 10″ to 12″ range, spiral patterns begin to emerge and with good seeing conditions, you can see “patchiness” in structure as nebulous areas are revealed, and the western half is deeply outlined with a dark dustlane. But hang on…

Because the best is yet to come!

Wednesday, October 3 – Tonight return to NGC 7331 with all the aperture you have. What we are about to look at is truly a challenge and requires dark skies, optimal position and excellent conditions. Now breathe the scope about one half a degree south-southwest and behold one of the most famous galaxy clusters in the night.

In 1877, French astronomer Edouard Stephan was using the first telescope designed with a coated mirror when he discovered something a bit more with NGC 7331. He found a group of nearby galaxies! This faint gathering of five is now known as “Stephan’s Quintet” and its members are no further apart than the diameter of our own Milky Way galaxy.

Visually in a large scope, these members are all rather faint, but their proximity is what makes them such a curiosity. The Quintet is made up of five galaxies numbered NGC 7317, 7318, 7318A, 7318B, 7319 and the largest is 7320. Even with a 12.5″ telescope, this author has never seen them as much more than tiny, barely-there objects that look like ghosts of rice grains on a dinner plate. So why bother? Because I’ve seen them with large aperture…

What our backyard equipment can never reveal is what else exists within this area – more than 100 star clusters and several dwarf galaxies. Some 100 million years ago, the galaxies collided and left long streamers of their materials which created star forming regions of their own, and this tidal pull keeps them connected. The stars within the galaxies themselves are nearly a billion years old, but between them lie much younger ones. Although we cannot see them, you can make out the soft sheen of the galactic nuclei of our interacting group.

Enjoy their faint mystery!

Thursday, October 4 – Today in 1957, the USSR’s Sputnik 1 made space history as it became the first manmade object to orbit the earth. The Earth’s first artificial satellite was tiny, roughly the size of a basketball, and weighed no more than the average man. Every 98 minutes it swung around Earth in its elliptical orbit…and changed everything. It was the beginning of the “Space Race.” Many of us old enough to remember Sputnik’s grand passes will also recall just how inspiring it was. Take the time with your children or grandchildren to check heavens-above.com for visible passes of the ISS and think about how much our world has changed in just 50 years!

Tonight we’re headed towards the southwest corner star of the Great Square of Pegasus – Alpha. Our goal will be 11th magnitude NGC 7479 located about 3 degrees south (RA 23:04.9 Dec +12:19).

Discovered by Sir William Herschel in 1784 and cataloged as H I.55, this barred spiral galaxy can be spotted in average telescopes and comes to beautiful life with larger aperture. Also known as Caldwell 44 on Sir Patrick Moore’s observing list, what makes this galaxy special is its delicate “S” shape. Smaller scopes will easily see the central bar structure of this 105 million light-year distant island universe, and as aperture increases, the western arm will become more dominant. This arm itself is a wonderful mystery – containing more mass than it should and a turbulent structure. It is believed that perhaps a minor merger may have at one time occurred, yet no evidence of a companion galaxy can be found.

On July 27, 1990, a supernova occurred near NGC 7479’s nucleus and reached a magnitude of 16. When observed in the radio band, there is a polarized jet near the bright nucleus that is unlike any other structure known. If at first you do not see a great deal of detail, relax… Allow your mind and eye time to look carefully. Even with telescopes as small as 8-10″ structure can easily be seen. The central bar becomes “clumpy” and this well-studied Seyfert region is home to an abundance of molecular gas and forming stars.

Enjoy this incredible galaxy…

Friday, October 5 – Today marks the birthdate of Robert Goddard. Born 1882, Goddard is known as the father of modern rocketry – and with good reason.

In 1907, Goddard came into the public eye as a cloud of smoke erupted from the basement of the physics building in Worcester Polytechnic Institute where he had just fired a powder rocket. By 1914, he had patented the use of liquid rocket fuel and two- or three-stage solid fuel rockets. His work continued as he sought methods of putting equipment ever higher, and by 1920 he had envisioned his rockets reaching the Moon. Among his many achievements, he proved that a rocket would work in a vacuum, and by 1926 the first scientific equipment went along for the ride. By 1932, Goddard was guiding those flights and by 1937 had the motors pivoting on gimbals and controlled gyroscopically. His lifetime of work went pretty much unnoticed until the dawn of the Space Age, but in 1959 (14 years after his death) he received his acclaim at last as NASA’s Goddard Space Flight Center was established in his memory.

Today in 1923, Edwin Hubble was also busy as he discovered the first Cepheid variable in M31 – the Andromeda Galaxy. Hubble’s discovery was crucial in proving that objects once classed as “spiral nebulae” were actually independent and external stellar systems like our own Milky Way.

Tonight let’s look at a Cepheid variable as we head towards Eta Aquilae, almost a fistwidth due south of bright Altair.

Discovered by Edward Pigott in 1784, Eta is a Cepheid variable star around 1200 light-years away, but its beauty can be followed easily with the unaided eye. Ranging almost a full magnitude in a period of slightly over 7 days, this yellow supergiant is 3000 times brighter than our own Sun and around 60 times larger. Watch over the days as it takes about 48 hours to achieve maximum brightness and rivals nearby Beta – then falls slowly over the next 5 days.

Saturday, October 6 – While time and the stars appear to stand still and astronomical twilight begins earlier each night, let’s take one last look at the exiting constellation of Sagittarius. Our study for this evening is strictly a telescopic challenge for skilled observers. Set your sights about 2 degrees northeast of easy double 54 Sagittarii and around 7 degrees west of Beta Capricorni (RA 19 44 57.80 Dec -14 48 11.0) and let’s have a look at NGC 6822.

Often referred to as “Barnard’s Galaxy,” for its discoverer (E. E. Barnard – 1884), this unusual customer is actually a member of our local galaxy group. For the 4″ to 6″ telescope, this 11th magnitude, 1.7 million light-year distant object will not be easy, but it can be achieved with good conditions. Lower power is essential in even larger scopes, and those into the 12″ to 16″ range will see NGC 6822 burst into stunning resolution. This author has found that “Barnard’s Galaxy” almost appears like an open cluster overlaid with nebulosity, but the experienced eye will clearly see that the “shine” behind the stars is galactic in nature. It’s a very clumpy and unusual galaxy – one that I think you will very much enjoy. Be sure to look for small, pale blue, 10th magnitude planetary nebula NGC 6818 in the same field to the north-northwest. This pair rocks!

Sunday, October 7 – Today celebrates the birthday of Niels Bohr. Born 1885, Bohr was a pioneer Danish atomic physicist. If Niels were alive today, he’d be out early looking at the beautiful sight of Saturn, Venus and Regulus and the crescent Moon grouping together and gracing the predawn skies. It’s worth getting up for! For some lucky viewers, Regulus is so close to the Moon that it could be an occultation event. Be sure to check IOTA.

Now let’s get some practice in Capricornus as tonight we’ll take on a more challenging target with confidence. Locate the centermost bright star in the northern half of the constellation – Theta – because we’re headed for the “Saturn Nebula.”

Three finger-widths north of Theta you will see dimmer Nu, and only one finger-width west is NGC 7009 (RA 21 04 10.88 Dec -11 21 48.3). This wonderful blue planetary is around 8th magnitude and achievable in small scopes and large binoculars. NGC 7009 was the first discovery of Sir William Herschel on September 7, 1782 – the night he started his sky survey – and he cataloged it as H IV.1. Sir William’s original notes describe it as: “very bright nearly round planetary, not well-defined disk.”

When viewed by Lord Rosse in the 1840s, he gave it the nickname Saturn Nebula, and it is considered one of the nine Struve rare celestial objects. Also known as Bennett 127 and Caldwell 55, it is generally believed to be around 2400 light-years away – but not so far that it doesn’t make about every list known as an all time great!

Even at moderate magnification, you will see the elliptical shape which gave rise to its moniker. With larger scopes, those “ring like” projections become even clearer as the 11th magnitude central star becomes apparent. No matter which aperture you choose, this challenging object is well worth the hunt. You can do it!