Tag Archives: Betelgeuse

AAVSO Writer’s Bureau Digest For 22 April 2014

2013dec20_aavso_logoThe AAVSO Writer’s Bureau, hosted by the American Association of Variable Star Observers (www.aavso.org), is a selective aggregator of high-quality science content for the amateur astronomer. Several astronomy bloggers, science writers, and official astronomy publishers and organizations provide articles free-of-charge for redistribution through the AAVSO-WB. The five most recent Writer’s Bureau posts are presented below with direct links to the full articles on the author’s own website. CNYO thanks the authors and the AAVSO for making these articles available for free to all astronomy groups!

Starbirth in the Neighborhood

C.C. Petersen, The Spacewriter

2014april22__5_M83Galaxies are huge collections of stars, gas, dust, black holes, and planets. The Milky Way is a good example of a spiral galaxy. It also happens to have a bar of gas and dust and stars across its center, and many places where stars are being born. It turns that when astronomers look at other galaxies, particular spiral galaxies (and many colliding galaxies), they also see regions of starbirth.

Hubble Space Telescope has been astronomy’s “go to” machine in space when astronomers want to look at something like a distant galaxy. This Hubble image shows the pinwheel (spiral) galaxy M83, which lies in our southern hemisphere skies in the constellation Hydra. It’s about 15 million light-years away, and, as you can see here, is ablaze with starbirth regions spread across 50,000 light-years of space.

Read the full article at: thespacewriter.com/wp/2014/01/26/starbirth-in-the-neighborhood/

A Cosmic Bubble That’ll Soon Pop. Hard.

Phil Plait, slate.com

2014april22__4_jeffhusted_sharpless2_308Sometimes, I’m pretty happy our planet circles a relatively calm, normal star. Because when I look at stars like EZ Canis Majoris (aka WR 6, HR 2583, HD 50896, and other aliases), I think that things around here could be a lot less conducive for life.

Why? Because this:

Pretty, isn’t it? But the beauty belies a true monster.

This photo was taken by Jeff Husted, an astrophotographer who observers in the western US. It shows the star EZ CMa (for short), the star just left of center of that ethereal glowing bubble of gas. It’s what’s called a Wolf-Rayet star, one of the more terrifying beasts in the galaxy’s menagerie. It’s a star that started out life with more than 40 times the mass of the Sun, which made it super-hot and extraordinarily luminous. Stars like that can be hundreds of thousands of times as bright as the Sun! A planet orbiting it as close as the Earth to the Sun would be cooked to a vapor pretty rapidly.

Read the full article at: www.slate.com/blogs/…cosmic_bubble_from_a_galactic_monster.html

The Final Countdown Before a Supernova

Phil Plait, slate.com

2014april22__3_hst_sbw1I’m sometimes asked what I think the next exploding star in our galaxy will be. Most people expect I’ll say Betelgeuse, the red supergiant marking Orion’s right shoulder.

But Betelgeuse may not go supernova for another million years, which is a long, long time. There are several stars much closer to The End, and I recently learned of a new one: SBW1.

The star is a blue supergiant, a hot, energetic beast probably about 20 or so times the mass of the Sun. Stars like that don’t live long, just a few million years tops. But we know (we think) it’ll explode much sooner than that, because of that ring you see in the Hubble picture above. How does that ring tell us anything? Ah, glad you asked.

Read the full article at: www.slate.com/blogs/…/sbw1_a_star_on_the_verge_of_supernova.html

A Superluminous Supernova

CfA News, Harvard

2014april22__2_su201401Supernovae are the explosive deaths of massive stars. Among the most momentous events in the cosmos, they disburse into space all of the chemical elements that were produced inside their progenitor stars, including most of the elements essential for making planets and life. Astronomers have recognized for decades that there are several different kinds of supernovae, most fundamentally those that originate from a single massive star and those that develop when one member of a pair of binary stars becomes massive by feeding on its neighbor. Other factors like the stellar composition also come into account. Sorting out all these various complications is critical if astronomers want to be able to reliably classify any particular supernovae and thereby infer its intrinsic brightness, and then use its observed brightness as a measure of its distance.

Recent wide-field surveys searching for supernovae have found that the conventional schema for classifying supernovae may be even more complicated than previously thought. A few years ago a new class called superluminous supernovae was found, characterized by their emitting total radiated energies equal to about ten billion suns shining for a year. Some of these new objects were discovered at cosmological distances, helping to cement the notion that new types were being discovered, and further studies have found even more subdivisions, also based among other things on composition. These new superluminous supernovae can be identified and characterized by the particular way their light fades away after the brightness peak, driven in part by the radioactive decay of elements manufactured in the explosions.

Read the full article at: www.cfa.harvard.edu/news/su201401

New Cutoff For Star Sizes

John Bochanski, Sky & Telescope

2014april22__1_Brown_DwarfAstronomers have found a gap between “real” and “failed” stars.

What does the smallest star look like? This question is deceptively difficult to answer. Stars spend most of their lives fusing hydrogen in their cores, a prime time of life called the “main sequence.” As you go down the scale of stellar sizes on this sequence, stars become dimmer, cooler, and less massive. But determining the absolute properties of the smallest stars — their mass, radius, temperature, and overall light output — is challenging for at least three big reasons.

Read the full article at: www.skyandtelescope.com/astronomy-news/new-cutoff-for-star-sizes/

CNYO Observing Log: Baltimore Woods, 22 March 2014 (And An Erigone Summary)

Greetings fellow astrophiles!

The often-announced (on this site, anyway) Regulus occultation by asteroid (163) Erigone on the morning of March 20th was a near-wash (no rain, but plenty of cloud cover), with only a few messages being passed around at midnight to see if anyone was even going to try for 2:00 a.m. That said, the International Occultation Timing Association (IOTA) got lots of good press and, with luck, a similarly notable occultation will occur to catch other eyes and instigate the IOTA to prep another big public recording effort. Those who want to relive the non-event can watch the Slooh Community Observatory coverage in the youtube video below.

Then, two days later, Bob Piekiel with his Meade C11 and I with my New Moon Telescope 12.5″ Dob treated two couples at Baltimore Woods to the kind of crystal clear and steady skies you read out but usually never have the good fortune to be out for. With the late March and early April temperatures beginning to melt the high hills of ice and snow around all the big parking lots in the area, the Baltimore Woods setup was a bit solid, a bit slushy, and quite dirty. Our four-person audience arrived early in time to watch the clear skies darken and Jupiter, Sirius, and Betelgeuse first appear in the South/Southwest sky. For the next 90 minutes or so, the observing list included Jupiter (several times at several magnifications, both early in the evening and after the skies had sufficiently darkened to bring out more detail), the Pleiades (M45), the Beehive Cluster (M44), the Orion Nebula (M42), Alcor and Mizar in the handle of the Big Dipper, the Andromeda Galaxy (M31) and its prominent satellites (M32 and M110) very low on the horizon (very likely our last catches of our sister galaxy for several months to come), and even M82 to say that we had, at least, seen the location of the recent supernova (if not a last few photons from it).

In an attempt to help someone remember as many constellations as possible at the Liverpool Public Library lecture a few weeks prior, I retold one of the more memorable tales of the winter star groupings of Orion the Hunter, Taurus the Bull, Canis Major (the big dog), Canis Minor (the little dog), and the Pleiades that I picked up from the excellent Dover book Star Lore: Myths, Legends, and Facts by William Tyler Olcott (which you can even read and download for free in an earlier form at archive.org).

Long story short, the Pleiades (also known as the Seven Sisters or the Seven Virgins) were the target of Orion’s rather significant attention, so much so that in his last run to them, the ever-invasive Zeus placed an equally significant bull in Orion’s path, leaving Orion and his two dogs (Canis Major and Canis Minor) stuck in their tracks. As is apparent from the images below, these four constellations (and one star cluster/Messier Object) are all tightly spaced in the Winter Sky. Better still, the end of Winter even finds these constellations standing on the horizon (instead of upside down in morning Autumn skies), making the picture all the more easily seen. As Orion is second only to the Big Dipper in terms of ease-of-seeing by practically everyone (raised in the tradition of Western Constellation arrangements, anyway), it’s the start constellation from which to find the other three. Canis Major is easily found by its shoulder star Sirius, the brightest start in our nighttime sky. Canis Minor is a leap from Sirius to Procyon, also a prominent star. Taurus the Bull is easily found by its head, the local star cluster known as the Hyades, and its orange-red eye, Aldebaran. The small sisters lie within the boundary of Taurus in a cluster that to the slightly near-sighted might just look like a fuzzy patch (but which, in binoculars, reveals numerous tightly-packed stars).

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Our cast of characters (and nearest neighbors). Image made with Starry Night Pro.

2014march22_stars

The prominent stars in their starring roles. Image made with Starry Night Pro.

After packing up around 9:30 (about when the temperatures began to drop precipitously), I managed a single long-exposure image with my Canon T3i of the region above – quite possibly my last good look at the most famous Winter grouping until they appear again in the morning Autumn skies.

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Final scene from Baltimore Woods (with story labels). Click for a larger view.

CNYO Observing Log: Baltimore Woods, 21 February 2014

Greetings fellow astrophiles,

This observing log will be as short as the observing window was.

The evening forecast for Friday, February 21st was iffy all afternoon, with a potential clearing predicted from winds coming from the Northwest, but still predictions of up-to-moderate cloud cover until later in the evening. In our great optimism, Bob Piekiel (with his Celestron NexStar 11) and I (with my 12.5″ New Moon Telescope Dobsonian “Ruby”) had our scopes setup and at-the-ready for attending viewers.

2014march11_bw_feb21

A fuzzy image for a fuzzy evening.

Over the course of about 90 minutes, 8 attendees in two small blocks (9 if we include Larry Slosberg’s attending Canis “Luna”) bore witness to a very unpredictable sky. “Sucker holes” (those clearings within the clouds that appear to offer you a minute or two of viewing, only to close up as soon as your scope is pointed) were the order of the evening, providing only limited views of Sirius, Rigel, and Betelgeuse (three of the brightest stars that just made for targets in the wispy edges of cloud bands), the great Orion Nebula (clear when visible, but lessened by the low-transparency conditions), the Pleiades (giving only views of the brightest stars in the cluster), and Jupiter (which did impress for the five minutes it was visible).

Such evenings are never a loss for public viewing sessions, as the downtime gives everyone a chance to ask questions, wax astronomical, and keep track of any other interesting happenings going on that come up in conversation. Pack-up occurred around 9:30, finishing just as a first few snowflakes began to fall in the Baltimore Woods parking lot.