Jane Houston Jones » Regulus

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

The Harry Potter Objects – a year-round literary stargazing project – Updated July 2011

jane — Thu, 09 Jul 2009 19:15:49 +0000

It’s just a few days until Harry Potter And The Deathly Hallows, ‘Part 2′ opens, so I am updating my literary stargazing project. I even added a few new objects to the list. So head up to the astronomy tower at your own Hogwarts and look up into the summer night sky. Did you buy a telescope at the telescope shop in Diagon Alley like Harry Potter’s collapsible brass telescope? If not, don’t worry, most of these objects can be seen just using your eyes. Have fun and let me know if you complete your O.W.L. – in Literary Stargazing.

Here is a July 2011 star chart where you can find many of the constellations and stars listed below. Use it to find the summer Harry Potter objects such as the constellations Draco, Cygnus and Scorpius, plus stars Arcturus and Sinestra (in the constellation Ophiuchus – it’s the star at the end of the arm holding the snake Serpens Cauda). The constellation Phoenix is a challenging object in the southern sky — try looking for it in November. Many of these objects are best seen at other times of the year. Make your own StarWheel and find out when and where to look.

This article was researched, compiled, written and observed by Jane Houston Jones, Caroline Sakaguchi Kunioka, Elizabeth and Catherine Spiers. More about the authors at the end of the article.

Elizabeth, Caroline, Catherine and Jane form a girl cluster before observing the Harry Potter Objects

What do Sirius, Arcturus and Pollux have in common, besides being the brightest stars in their respective constellations? They are all characters in the popular Harry Potter books! Translated into over 70 languages, these books have universal appeal, and this project paves the way to introduce amateur astronomy to a new generation of stargazers.

This list might be just the “hook” to get your favorite muggle or wizard to step outside for a night of stargazing. “Come see Sirius Black’s star” or “Let’s try to find Draco Malfoy’s constellation” could be the beginning of a family, museum, planetarium, or community star party. Or head over to your favorite bookstore, library or movie theater for some sidewalk astronomy, especially if Luna is in the sky.

The Harry Potter Objects
Observe and/or read about these objects for your honorary O.W.L. – Ordinary Wizarding Level award in Literary Stargazing

Sirius – Sirius Black
Arcturus – Arcturus Black
Regulus – Regulus Black
Pollux – Pollux Black
Alphard – Alphard Black
Bellatrix – Bellatrix (Black) Lestrange
Merope – Merope (Gaunt) Riddle
Sinistra – Professor Aurora Sinistra, Astronomy Professor
Eta Argus – Argus Filch
Rastaban – Rastaban Lestrange
Cygnus – Cygnus Black
Orion – Orion Black
Andromeda – Andromeda aka Dromeda (Black) Tonks
Cassiopeia – Cassiopeia Black is the Great Aunt of Sirius Black
Draco – Draco Malfoy
Scorpius – Scorpius Malfoy
Luna – Luna Lovegood
Phoenix – The Order of the Phoenix
Aquila – Ravenclaw animal is a golden eagle
Leo – Gryffindor animal is a golden lion
Serpens, Hydra – Slytherin animal is a silver snake
Vulpecula, Lynx, Lupus – Hufflepuff animal is a badger. The Fox, Lynx and Wolf constellations are the closest to a badger.

Read about these additional objects and you will earn your honorary N.E.W.T. – Nastily Exhausting Wizarding Tests award in Advanced Literary Stargazing.

Albus 1 – Albus Dumbledore
Amycus 55576 – Amycus Carrow is a Death Eater
Ginevra 613 – Ginevra (Ginny) Weasley
Hermione 121 – Hermione Granger
Fenrir – Fenrir Greyback

Here is the detail on each object and each character from the books or from the Genealogy charts:

Sirius – Alpha Canis Majoris From Orion, look south and to the east to find brilliant Sirius, the brightest star in the sky. Sirius is also the brightest star in the constellation Canis Major, the Greater Dog. Canis Major is Orion’s larger hunting dog. Sirius is only 8.6 light years away, making it a popular “birthday star” for your favorite 8-year old. It’s a white class A (A1) hydrogen-fusing main sequence dwarf, shining at magnitude -1.46. Best seen in the winter.

Sirius Black is Harry Potter’s godfather. Sirius can turn himself into a black dog. His nickname, Padfoot, is a name North Englanders have for the magical black dogs who guard graveyards and can vanish instantly.

Arcturus – Alpha Boötis Arcturus is the brightest star in the constellation Boötes. Arcturus, the “Bear Watcher,” follows Ursa Major, the Great Bear, around the pole. Arcturus is 37 light years away. It is a classic orange class K (K1) giant star shining at –0.04. Best seen in the summer.

Arcturus Black is Sirius Black’s grandfather

Regulus – Alpha Leonis Regulus is the heart of Leo the Lion. At a distance of only 77 light years, it shines in our sky at magnitude 1.35. In Latin it means “the little king”. Regulus is bluish-white class B (B7) main sequence star. Best seen in the spring.

Regulus Black is Sirius Black’s younger and more beloved brother. Readers never meet him directly. Regulus became a Death Eater at the age of 16. Regulus Black was stronger, braver and more like his brother than anyone knew. Regulus, the star, is the heart of the lion, which is the sign of the house of Griffindor.

Pollux – Beta Geminorum Pollux is a star with a planet, and one of the “twin” stars Castor and Pollux of the constellation Gemini. They are twins in mythology only. Pollux is an orange-colored cool class K (K0) giant with a planet is 34 light years away, while Castor is white and 50 light years away. The planet orbiting Pollux has a mass 3 times that of Jupiter, orbits in a nearly circular path at a average distance of 1.69 Astronomical Units (11 percent farther than Mars is from the Sun) with a period of 590 days (1.6 years). Best seen in the winter.

Pollux Black – the maternal grandfather of Sirius Black.

Alphard – Alpha Hydrae Alphard is not well known, but is surprisingly prominent. Alphard dominates the dim constellation Hydra, the Water Serpent, where it marks the heart of the snake. The star is an orange class K (K3) giant 175 light years away, shining at magnitude 1.98. It is found in a blank area of the sky, and its Arabic name means “the solitary one.” Best seen in the spring.

Alphard Black – Sirius Black’s uncle. He left his money to Sirius. For this gesture, he was disowned by the Black family. He is represented by a burn mark on the family tapestry. Readers find that very few Blacks loved Sirius, and so perhaps, Alphard’s name is fitting. It is also interesting that Alphard Black was a student in the house of Slytherin.

Bellatrix – Gamma Orionis Bellatrix is a blue-white and luminous star shining at magnitude 1.64. It is one of the hotter naked eye stars, at the hot end of class B (B2) and is 240 light years distant. The name Bellatrix translates from Latin as “the female warrior”, and sometimes the “Amazon Star.” Best seen in the winter.

Bellatrix (Black) Lestrange – Sirius Black’s cousin and killer. She spent time in Azkaban prison for giving Unforgivable Curses and for torturing Frank and Alice Longbottom.

Merope – or 23 Tauri, one of the Pleiades. Merope shines at a faint 4.18 magnitude and is 385 light years distant. The Pleiades is a cluster of brilliant blue white class B (B6) stars. They are named for the daughters of Atlas and Pleione. Merope is 4th in brightness and is famous for its surrounding cloud of dusty gas which is named the Merope Nebula, or IC 349. The Pleiades stars are not hot enough to ionize the gas and make it glow. Instead, the dust grains embedded in the cloud scatter and reflect the starlight, and we see this starlight as the Pleiades Reflection nebula. Originally thought to be a remnant of the stellar birth, it is really a chance encounter. The cluster is passing through a random interstellar cloud, and the Pleiades leave a wake as the cloud rushes by. Best seen in winter.

Merope (Gaunt) Riddle – Merope tricked Tom Riddle into marrying her with a love potion. Later she gave birth to a son at a Muggle orphanage and died after naming her child Tom Marvolo Riddle. Merope Gaunt is named after a stunningly apt myth. Merope was the youngest of the sisters and the only one to marry a mortal. Accounts differ as to whether she hid herself in shame or whether her star faded away as a result.

Sinistra – Nu Ophiuchi Sinistra is a magnitude 3.5 orange spectral class K (KO) star in the constellation Ophiuchus. It carries the traditional Latin name Sinistra, meaning “left” or “left hand” despite the fact that Nu Ophiuchi marks the Serpent Bearer’s right hand. It is 155 light years from Earth. Best seen in the summer. To find Sinistra on the star chart, look for where the constellation Ophiuchus intersects Serpens Cauda. think of that as the hand of Ophiuchus, grasping the serpent.

Professor Aurora Sinistra teaches Astronomy at Hogwarts. The class is taught at midnight in the highest tower at Hogwarts offering the best view of the night sky. Students study the night sky to chart the stars, moons, and planets. For homework, students have made models of the planets, moons, and stars. Her first name “Aurora” implies the professor is a “light” witch, not a practitioner of the dark arts, and a student of the skies.

Eta Argus was formerly in the constellation Argus, now part of the keel of the constellation, Carina. English astronomer Francis Abbot was sentenced to 7 years transportation, and sent to Hobart Town,Tasmania to serve his sentence in 1844. After serving his sentence he became a flourishing businessman and respected astronomer, who was the first to draw attention to the changes in the variable star Eta Argus. This star is now known as Eta Carinae or Eta Carina. Since this object is visible to observers in the southern hemisphere, you can observe the beautiful Hubble image instead.

Argus Filch is the Hogwarts caretaker. He’s a cantankerous, nasty man who detests the students.

Rastaban – Beta Draconis Rastaban is the third brightest star in the constellation of Draco. It is a G-type giant star, with spectral class G2 and an apparent visual magnitude of approximately 2.79. Its distance from the Sun is around 360 light years. It is a binary star, with a binary star designation of ADS 10611, in which the supergiant is orbited by a dwarf companion once every four millennia or so.

Bellatrix Lestrange’s brother-in-law is Rabastan Lestrange. (I know the spelling is different)

Cygnus
Cygnus Black is Sirius Black’s Uncle

Orion
Orion Black is the Father of Sirius and Regulus Black

Andromeda
Andromeda (Black), a pure-blood witch was the widow of Ted Tonks, mother of Nymphadora Tonks, who preferred to be called Tonks or sometimes Dora. She was the mother-in-law of Remus Lupin and grandmother of Ted Lupin. She was Sirius Black’s favorite cousin

Cassiopeia
Cassiopeia Black is the Great Aunt of Sirius Black

Draco
Draco Malfoy is a Slytherin student and Harry Potter’s arch enemy.

Scorpius
Scorpius Malfoy – son to Draco, referred to in epilogue.

Luna – The name “Luna” is Latin for the moon.

Luna Lovegood is a student in Ravenclaw and in Ginny Weasley’s class. She is absentminded and has unconventional patterns of thought. The moon was once thought to induce insanity, but we now know it induces observing enjoyment. Luna’s nickname is Loony.

Phoenix
Order of the Phoenix – The Order is a group of witches and wizards, led by Hogwarts headmaster Albus Dumbledore, dedicated to fighting evil Lord Voldemort and his followers.

Aquila is the animal of the Ravenclaw House
Leo is the animal of the Gryffindor Gouse
Serpens, Hydra is the animal of the Slytherin House
Vulpecula, Lynx, Lupus reminds us of the badger, who has no constellation, Hufflepuff’s animal.

Extra Credit – these are some challenging or impossible objects to see. But they have a Harry Potter connection, so they are fun to learn about.

Amycus 55576 is a Centaur – half asteroid, half comet.
Amycus Carrow is a Death Eater.

Ginevra 613 Ginevra is a minor planet orbiting the Sun.
Ginevra Molly “Ginny” Weasley is a pure-blood witch, and the first female to be born into the Weasley line for several generations.

Hermione 121 is an asteroid I have actually seen through my own telescope, during an occultation. Here is more information about Hermione, the asteroid.
Hermione Jean Granger is a Muggle-born Gryffindor student

Albus 1 – A Very Bright White Dwarf Candidate. Albus 1 is a DA-type white dwarf located at about 40 pc. If its nature is confirmed, Albus 1 would be the sixth brightest isolated white dwarf in the sky, which would make it an excellent spectrophotometric standard.

Albus Percival Wulfric Brian Dumbledore – headmaster of Hogwarts School of Witchcraft and Wizardry

Fenrir is a moon of Saturn. Retrograde satellites are named after Norse giants.
Fenrir Greyback is the name of a violent werewolf whose allegiance lies with the Death Eaters.

About the authors/observers: Jane Houston Jones wrote the astronomy segments and edited the whole writeup. Caroline Sakaguchi Kunioka researched and wrote the Potter segments, edited Jane’s edits and came up with the idea in the first place. Elizabeth and Catherine are our younger sidewalk astronomers, both with their own telescopes. Elizabeth is an avid Potter fan who contributed Potter lore and lots of details to the project. Catherine enjoyed looking for the objects in the night sky, and helped field test the list at our favorite desert observing locations. All four of us are active members of the Old Town Sidewalk Astronomers, and we all love to read books, too.