Jane Houston Jones » Milky Way

Spring stargazing: the Milky Way and beyond!

jane — Tue, 09 Apr 2013 22:56:35 +0000

Follow the dipper arc to Arcturus, then spike to Spica

Omega Centauri globular cluster 35 degrees below Spica

Springtime is my favorite observing season. In the course of an evening you can face away from our own galaxy and feast your eyes on other Milky Ways, while tracking down some of the most spectacular objects tangled among the stars and dust of our own galaxy.

Omega Centauri is one of them. It’s the largest of the 150+ globular clusters discovered in our own Milky Way Galaxy. There may be even more undiscovered globular clusters hidden behind the gas and dust of our galaxy. Omega Centauri was discovered by Edmund Halley in 1677 as a nebula, but it had been listed in Ptolemy’s catalog 2000 years ago as a star! It’s located about 15,800 light-years from Earth and contains several million Population II stars. The stars in its center are so crowded that they are estimated to average only 0.1 light years away from each other. It is about 12 billion years old, and there is some speculation that Omega Centauri may be the core of a dwarf galaxy which was disrupted, destroyed and absorbed in an encounter with the Milky Way.

This spectacular object is well known to southern hemisphere observers, but it may come as a surprise that it can be seen from many northern hemisphere locations as well. If you are south of the 25th parallel or 25° (degrees) North latitude you should be able to see it 20° above the horizon, and located 35° below Virgo’s great blue-white star, Spica. I’ve observed it from 37° North (Lake Sonoma, CA) several times (from a hill with a negative horizon) and at 33° N in this writeup, where it appeared less than 20° above the horizon definitely! It’s been seen from 42° North as well, from a very flat horizon. It’s a naked eye object, but often the horizon is hazy, so scan with binoculars if you don’t see it with your eyes.

NGC 5128, Centaurus A Galaxy, and NGC 5139 Omega Centauri, the largest Globular Cluster in our Milky Way

To find Omega Centauri, you’ll first have to find Spica, the brightest star in Virgo. It helps right now that golden Saturn is near by. To find Spica, continue the curve of the big dipper handle and “arc to Arcturus, and then spike to Spica”. Spica transits — when it reaches its highest point in the sky — at around midnight daylight saving time. Use this table of transit times for major solar system objects and bright stars and select your observing dates, object (Spica in this case) and your location and press “compute”. “Alt” next to the transit time at your location indicates Spica’s altitude above the horizon. Spica and Omega Centauri transit at the same time, so look about 35° (one clenched fist is 10°) directly below Spica to look for an oval hazy cluster the size of the full moon. Can you see individual stars? Does it look round or oval? Try with your eyes, then with binoculars.

After confirming my view of Omega Centauri and making this little sketch (sketch view as seen through my binoculars), I opened my Herald Bobroff AstroAtlas to the Centaurus constellation pages and looked at what else was in the vicinity of Omega Centauri. I remembered a favorite galaxy, NGC5128, officially named Centaurus A, but nicknamed the hamburger galaxy for obvious reasons. Now I’ve seen both of these objects from Australian skies where they are not hugging the horizon. But even through a partially cloudy horizon, I was able to see this fabulous object, with its dark dust lane bisecting the oval galaxy.

NGC5128 is one of the closest radio galaxies to Earth, so its active galactic nucleus has been extensively studied by professional astronomers, and a supernova was detected in the galaxy’s dust lane in 1986. The Spitzer Space Telescope studies have confirmed that Centaurus A is colliding with and devouring a smaller spiral galaxy! Centaurus A is located approximately 4° north of Omega Centauri, and because the galaxy has a high surface brightness and relatively large angular size (2/3 the apparent size of Omega Centauri), it’s visible to the naked eye under good conditions. My sketch was made with difficulty, by aiming my 14.5-inch reflector (with a 10mm Radian eyepiece for 200x) nearly horizontal and half-perched uncomfortably on the bottom step of my observing ladder.

M68 cluster in Hydra, NGC2903 Galaxy in Leo

Before moving on, I observed another object in the southern sky line between Spica and Omega Centauri, Globular Cluster M68, or NGC4590 in the constellation Hydra. I sketched an oval glow of stars within a diffuse squarish haze of fainter stars.

Now it was time to get vertical and observe some other objects higher in the sky. The beautiful constellation Leo was still well placed in the southwest sky after midnight. I opened my Night Sky Observer’s Guide Volume 2, the Spring and Summer volume to Leo. Gamma Leonis, or Algeiba, is a beautiful deep yellow/orange and pale yellow double star in the sickle (or backwards question mark or lion’s mane) of Leo’s head. Next, I moved to a fascinating red dwarf, Wolf 359, near the famous Leo galaxies M95, M96 and the Leo “trio” of galaxies. Wolf 359 moves 4.71″ (arcseconds) per year or 8′(arcminutes) in a century. It’s the third closest star to the sun, at 7.75 light years away. Only Alpha Centauri and Barnard’s Star are closer. At magnitude 13.6 (similar to Pluto’s magnitude) it’s faint, but the striking red color helps distinguish it from the other nearby stars.

Leo 1 near Regulas, Leo’s heart was my next target. A faint dwarf galaxy overshadowed by bright Regulus is a member of the local group of galaxies, and may be one of the most distant satellites of the Milky Way. Faint NGC2903 — a very pretty magnitude 9 barred spiral galaxy tangled in the starry lion’s mane was worth a sketch. It’s 31 million light years away, local but not attached to any local galaxy group. I had to go and have a look at the supernova in Leo’s M65 galaxy – here is Mojo’s animation of M65,combining two images of M65, one shot on 3/9/13 at Amboy Crater, and one shot on 4/6/13 at Chuckwalla Bench located at N 33° 39′ 37″, W 115° 32′ 26″

Comet C/2011 L4 (PANSTARRS) shot before dawn on 4/7/13, five-minute exposure

It dawned on me I hadn’t observed Saturn yet. Under fabulous steady skies, I was able to pump up the magnification of my 15-inch Litebox reflector to over 300x using a 6mm Televue Radian eyepiece. When I say “my” 14.5-inch Litebox, I mean Mojo’s — I have a 12.5-inch and 17.5-inch version of these fabulous time machines. This image taken by Anthony Wesley the same night shows Saturn as I viewed it. My visual view was not quite this vivid, but the contrast of the colors is very similar to what I saw, including the dark north polar region, so famous in the Cassini North Polar Hexagon images. The distinct band colors and darker north polar area I saw and sketched were varying shades of butterscotch and chocolate.

All that was left now was Comet PanSTARRS, and we had to wait until about 4:00 a.m. for Andromeda to rise in the northeastern sky. I observed it in my 7×50 Carton Adlerblick binoculars quickly and then pooped out and went to sleep until well after dawn. Mojo stayed up and took this lovely image, plus several more including a time sequence showing the comet’s motion. It’s really worth a look and a read and here’s the link. Until next dark sky observing night on May 11, I’m signing off!

Mojo’s images and report from the same night

A Dreamcatcher, And A Blanket Of Stars

jane — Mon, 31 Jan 2011 01:07:43 +0000

Red Willow Dreamcatcher with Big Dipper and Milky Way

The Fisher Stars, painting courtesy of Edwin Bighetti, Mathais Colomb First Nation

Wesakaychak Pointing - courtesy of Edwin Bighetti, Mathais Colomb First Nation

In March 2010, I was invited to be the keynote speaker at the Manitoba First Nations Education Resource Centre’s annual Science and Career Fair. Two participating schools from the Nisichawayasihk Cree Nation in Nelson House, Manitoba invited me to visit their community. So in November 2010 I spent two days with the students, teachers at the K-8th grade Otetiskiwin Kiskinwamahtowekamik School, and the 9-12th grade Nisichawayasihk Neyo Ohtinwak Collegiate.

After a day of school presentations in early November, I was invited to a community gathering of shared songs, the music of flute, hand and water drums, and stories from several storytellers. Joe Mercredi, a school cultural coordinator and a wonderful storyteller told several stories, after he played the flute – a six-hole flute made of mountain juniper by Navajo flute maker Jonah Thompson. Joe makes flutes, too, but he chose this one for this night because “it has a sweeter voice than his own,” he told me recently. Joe also helped me remember the stories he told that night two months ago. He told me that all stories are related to each other. How we remember them depends on what we need to learn at the time.

His first story is a variation of the Dakota Woodpecker Flute story. A poor young boy with no male relatives lived with his mother. He was friends with the chief’s daughter. They were good friends and spent much time together. When of age, he asked the chief for her hand. The chief questioned his ability to support his daughter. He was mortified and left the camp. After some days he fell asleep under an old cedar tree and was woken up by a woodpecker up in the tree. This being in the time when animals could speak to men, a conversation ensued and the young man was gifted with the first flute. In the end the two become a couple and the young man found fame and fortune as a flute maker. This story can be found in one of the Joseph Bruchac series “Keepers of the Earth/Sky/Night/Life” books.

Joe then held his Dreamcatcher, and told this story. Red Willow Woman was a woman who taught the children in her community until her death, and, when given the choice by the Great Mystery to be returned to her people, she chose to return as a red willow to demonstrate that every one has the ability to achieve greatness if one reaches beyond one’s limits. Red willow forms the frame of the Dreamcatcher.

You can see the big dipper stars (or Fisher stars) on the right side of the woven web within the red willow frame. And you can see a chaotic jumble of stars on the left. The legend of how Fisher became the Big Dipper and how animals of long ago decided to share summer and winter, and how the fisher came to be in the northern sky is told by Murdo Scribe, and is known as Murdo’s Story.

Long ago, in one part of the animal world and bird world it was always summer and in the other half of the world it was very cold with no warm weather. The northern animals and birds had to find summer. Fisher (a small wolverine) carried summer, and the summer animals chased him. They shot at him and an arrow hit Fisher and took him to the northern skies, with the summer. Fisher still lives in the northern sky, and summer is now shared with all animals and birds everywhere. Fisher can be found circling the North Star. Some people call him the big dipper.

The Dreamcatcher is formed from two willow branches depicting strength and softness intertwined — the need for give-and-take in a respectful loving relationship. Joe decided to map the Big and Little Dippers in the Dreamcatcher. But just like in the Wisakechak story of the Milky Way, he mapped the big dipper, but the trickster, Wisakechak decided to mess up some of the stars. You can see an extra star in the big dipper.

Legend tells that Wisakechak was meticulous in his placement of the stars, but Fox wanted Wisakechak to play with him, and got tired of waiting for him to finish so he grabbed the blanket of stars and scattered them all over the place. Those stars represent the Milky Way. If you look in the winter sky you will see Wisakechak (sometimes spelled Wesakaychak and many other ways, too) pointing to the Pleaides, which figure in many other legends. Wisakechak is represented by the constellation Orion.

You can see the big dipper stars in the web of the Dreamcatcher. The handle star, Alkaid is near the top of the Dreamcatcher , and you can see the bowl stars at 3 o’clock. There is one “extra” star woven into the web near the bowl, put there by the trickster, Wisakechak. And you also see the other stars from the blanket of stars Fox threw into the sky on the left side of the Dreamcatcher below the center hole. You’ll also see the thirteen tie-points, where the sinew is tied to the willow hoop. These thirteen ties represent the 13 new moons of a year.

After Joe finished his stories of Red Willow Woman, Wisakechak, the Fisher stars, and the Milky Way, he walked over to me and gave me his Dreamcatcher. As I look at my Dreamcatcher now, three months after my visit, I can still hear the drums, the flute and the stories of the stars I heard in Nelson House that snowy November night. Now, when I read Murdo’s Story I can see how all of these stories are related.

Murdo Scribe was born in Norway House, Manitoba and was a World War II veteran with the Canadian Army. After the war he returned to a life of fishing, trapping and seasonal work. In 1975, he was appointed coordinator of the Traditional Individualized Education Program with the Native Education Branch of the Manitoba Department of Education. He wrote many stories based on his own experiences and those of the elders he had known.

I thank Joe Mercredi, who is a master storyteller, maker of flutes, weaver of dreamcatchers for sharing these stories with me. I must also thank science educator Wilfred Buck, of the Manitoba First Nations Education Resource Centre, who I met two years ago at the NYAA (Ontario) Starfest when he gave a talk about Atchakosuk: The Spirit Lights Up Above . I have been slowly learning more about the spirit lights above. Two years ago, Wilfred ended his presentation with a quote from one elder, “We are blessed to live under a blanket of stars.”

I will do the same.

Moonrise over Chuckwalla Mountain

jane — Mon, 05 Jul 2010 01:12:51 +0000

Moonrise over Chuckwalla Mountains July 3, 2010 about 11:30 p.m.

Third quarter moon, a half hour later

My small 70mm Televue Ranger was used for the moon images

Summer dark sky observing means short nights, and it’s usually too hot for comfort in the Colorado desert location we love. But Mojo and I decided to pack a cooler full of ice cubes, and take our chances. The predicted daytime high was 102 F, and it would be (we persuaded ourselves) a few degrees cooler at “our” spot. The low temperature for the night was forecast to be 75 degrees. We could live with that!

It didn’t get dark enough to observe anything except planets until 9:00 p.m. and so we only had two and a half hours of dark sky before moonrise would make it too bright.

One of the benefits of living and observing in Southern California is that at latitude 33N, we can see deep into the southern skies.

Summer nights are just made for observing Scorpius. The Bug Nebula NGC 6302 is one of my favorites ever since I saw and sketched it high in the Australian skies in 1999. NGC 6231, the Table of Scorpius is another favorite. It’s an open cluster near Zeta Scorpii, the first star marking the Scorpion’s curvy tail.

This is a delightful region (great with binos too) full of Milky Way wonders, including emission nebula IC4628. Mojo captured the area beautifully in his image of Scorpius last night. The star cluster center bottom is NGC 6231, and the reddish patch just above it is the emission nebula IC4628.

This is the area I was aiming my big telescope at until about 11 p.m. when we could see the lunar light dome emerging. We finished up our projects and waited for that first “wedge” of moonlight to breech the mountain ridge to the east.

I took some afocal images using my Canon Powershot SD870IS Digital camera held at the eyepiece of my small refractor. I’m pretty happy with the results.

Since it was a short night, this is a short observing report.

Mojo’s report from the same night

The Chuckwalla Bench observing site. Scan the topography to see Chuckwalla Mountain to the east of our observing site (the green arrow).

Another third quarter moon observation

A morning comet

jane — Sat, 19 Jun 2010 21:04:20 +0000

Use a chart like this to locate where to look for your object

Can you find the constellation Perseus and comet McNaught in Mojo's lovely skyscape?

Mojo's photo of Comet McNaught

Quick comet sketch with notes. See the long ion tail, the bright coma, and the short dust tail in my sketches

Comet C/2009 R1 (McNaught) June 13, 3:45 am from Chuckwalla Bench observing site, Colorado Desert. Lat 33N, Long 114W, Elev 1400 ft

I wish everyone in the world could see just one comet! Right now, there is one visible just as the dawn brightens the night sky. Unfortunately, it’s not easy or convenient to see this one, and in another ten days it will disappear below our horizon. It’s just barely visible to the unaided eye. Timing your viewing window is tricky, too. You have to find a balance between the time the comet rises high enough to see, and the coming of dawn, which robs the night of its darkness and guidepost stars an hour or two later.

Here are some tips to help you have a successful comet viewing experience now or in the future. When you first hear about a visible comet, you can usually find some online sky charts from astronomy magazines such as Sky and Telescope and Astronomy. Many online sources can offer guidelines and observations, too.

Star charts are fine, but you have to go out and navigate the real sky to find unfamiliar constellations. From the city, or close to dawn, this is a real challenge. You may only see a few bright stars in the sky. Try to see the stars making up the constellation Perseus in Mojo’s image. I’ll admit, it isn’t easy, especially when you are rushing against time. Now, compare his image to the star chart. And you’ll soon see the figure of the hero, Perseus, starting to emerge.

I use the familiar “W” shaped constellation Cassiopeia as a signpost to locate Perseus. Then I see Perseus with his two running legs, joined at the bright star Alpha Perseus (Mirfak). Nearby you can see the naked-eye open cluster known as either Melotte 20 or the Alpha Perseii cluster. Next, I make a mental triangle out of Alpha, Delta and Kappa Perseii, the three bright stars closest to the comet shown on the star chart.

Finally, I aim my binoculars at the triangle of stars and hold my breath. Then I see it, and I quietly say “hello” to the swift celestial traveller. I get chills every time I see a comet. And this time is no different. A little green fuzzball is right where the comet should be.

Now I jump into action. I dust the cobwebs out of my brain, as well as I can at 3:45 am in the morning. I’ve just woken up from a short nap. I quickly sketch what I see in the eyepiece of my big telescope, taking care to mark any stars nearby, and note the time. Then I call everyone who is awake over for a look. We all move sluggishly in the near dawn light, like we are walking through sandy molasses. We share views with one another, through binoculars and a variety of telescopes large and small.

Overhead, the Milky Way has disappeared, and the glow of twilight grows brighter. I have yet another predawn observing target, so I quickly make a second sketch with a little more detail. Then I nod goodnight to the beautiful green comet, aim my binoculars just a little to the east and wait. It will be nearly one hour before Mercury will rise over the mountains.

This comet is making its first approach around the sun, in its long hyperbolic orbit from the Oort Cloud. At the time of my observation, the comet was 0.6 AU from the Sun and 1.1 AU from Earth. By the end of June, it will be lost to our view. It reaches perihelion on July 2nd when it is about 0.4 AU from the sun. Then it will fade and be seen no more.

Added postscript: According to this Space.com article, the comet may be visible “after June 22 both in the evening sky for a short while just after sunset very low above the north-northwest horizon and in the morning sky just before sunrise very low above the north-northeast horizon.” I’ll update if/when I learn more.

See more of Mojo’s photos from this observing night.

Read my other observing writeup from this same night.

Join our Old Town Sidewalk Astronomers email list and find out when our next dark sky outing will be. Or join us at our next in-town new telescope users clinic and planet/moon viewing event. Hey, that’s tonight, June 19! Clinic (RSVP required) begins before dark at 7 p.m. Star Party continues until 9:30 p.m. at Library Park in Monrovia, CA.