Jane Houston Jones » Draco

Quadrans Muralis: a demoted constellation lives on as the radiant of the January Quadrantids

jane — Fri, 31 Dec 2010 19:37:32 +0000

Johann Bode's 1801 Uranographia, showing Quadrans Murales, Boötes and other constellations

Boötes, Canes Venatici, Coma Berenices and Quadrans Muralis

The Northeast sky Jan 4 at 1:00 a.m. PST. Look between Ursa Major and Minor, and the bright star Arcturus in Boötes for the location of Quadrans Muralis on the Boötes-Draco border

Looking Northeast before sunrise, chart courtesy of Spaceweather.com

Most meteor showers radiate from a recognizable constellation like Leo’s Leonids, Gemini’s Geminids and Orion’s Orionids. What’s up with the January Quadrantids? Where do you find their constellation? In Quadrans Muralis, a demoted constellation.

The first 60+ Roman constellations didn’t cover the sky south of the equator, so over the years, astronomers took up the task and filled in the empty spaces with new constellations, including some in the northern sky.

The International Astronomical Union divided up the sky into official constellations in 1930. 88 constellations remained, but over 30 constellations didn’t make the cut. Among those demoted was Quadrans Muralis, the location of January’s brilliant, but brief Quadrantid meteor shower. Apis, the bee, Felis, the cat, and Solarium the sundial were other constellations demoted into obsoleteness. One ancient constellation, Argo Navis, didn’t survive, either. It’s the only one of the 48 constellations listed by 2nd century astronomer Ptolemy no longer officially recognized as a constellation. Like other pieces of large real estate, it was subdivided into smaller segments in the 17th century, and those constellations — Carina the Keel, Vela the Sails, and Puppis the Poop Deck — survived demotion.

There were good reasons to define and standardize the constellation list, even if it meant losing some historic or whimsical constellations. One reason, according to the IAU was “to aid in the naming of new variable stars, which brighten and fade rather than shine steadily. Such stars are named for the constellation in which they reside, so it is important to agree where one constellation ends and the next begins.”

Quadrans Muralis was added to the constellations by Joseph J. de Lalande in 1795, to commemorate the quadrant he used to observe and measure stellar positions. The quadrant was an instrument very similar to today’s sextant. A few years later, in the early 1800′s a meteor shower was discovered to radiate from this constellation, and the meteor shower was named for the constellation.

Created from stars found to the north of Boötes, the herdsmen; Quadrans Muralis can be found in a rich area of the northern sky filled with pretty constellations. The big and little dippers (the most recognizable parts of Ursa Major and Ursa Minor) are the most familiar sights but you’ll also find the Northern Crown, Corona Borealis, Boötes and his two hunting dogs Asterion and Chara in Canes Venatici, and Coma Berenices, the hair of Bernice. Take a tour of the area through binoculars on January 3rd before midnight while waiting for the radiant to rise.

Update for 2012 for Southern California meteor observers: “The radiant rises at 1:00 am local time and the moon sets at 3:00 am. The predicted peak (2:30 am Eastern 11:30 PST (07:30 UT January 4, 2011).

The Quadrantids (QUA) or January Bootids are active from January 1st through the 10th. A sharp maximum is predicted to occur near 0730 Universal Time on the 4th. This corresponds to 02:30 EST and 23:30 PST (January 3rd). This is good timing for viewers located in eastern North America as the radiant will rising above the northeastern horizon. It would even be better if the maximum were a bit later as the radiant would be located higher in the sky, producing more activity.

Rates will depend on the exact time of maximum and whether the moon is still above the horizon. Assuming the 0730 UT timing is correct, the further one is located in North America, the better. Eastern observers may be able to see 60-75 Quadrantids per hour. If your skies are very clear and dark, allowing you to see faint meteors, your rates could top 100 per hour. Observers located in the western portions of North American will have lower rates but will also have the opportunity to see Quadrantid “earthgrazers”. Earthgrazers are meteors that skim the upper portion of the atmosphere therefore lasting much longer than normal and producing long trails in the sky. These meteors can only be seen when the radiant lies close to the horizon. As the radiant rises, the meteor paths
will become shorter with shorter durations. Observers in the northern hemisphere outside of North America can expect to see a maximum of 25 Quadrantids per hour between moon set and dawn.

At maximum the radiant is located at 15:21 (230) +49. This position lies in a barren region of extreme northern Bootes, ten degrees northeast of the fourth magnitude star Beta Bootis. At 42 km/sec. the Quadrantids produce meteors of medium velocity. During exceptional activity some Quadrantid fireballs may be witnessed. Courtesy Bob Lundsford posting on the MeteorObs Yahoo Group.

Streaming video & a visibility map for tonight’s (January 3-4, 2012) Quadrantids meteor shower

Quadrantids History

IAU and the 88 Constellations

My What’s Up video for January 2011 (not 2012): The January 3-4 Quadrantid Meteor Shower

My What’s Up video for January 2012: Evolving planets, an asteroid to view (Eros), plus the Quadrantids

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.