Astronomy & Science

U.S. Forever Stamp to Feature Amateur Astrophotos

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The U.S. Postal Service's new Total Eclipse Forever stamp will feature photos by the well-know eclipse expert Fred Espenak, who is also a master of many different kinds of astrophotography.

USPS Totality Forever Stamp

The new Totality Forever stamp. Warm up the eclipse at left to reveal an image of the Moon.

When's the last time the work of an amateur astrophotographer has featured on a postage stamp? That's what will be happening on June 20th, when the U.S. Postal Service will release its new Total Eclipse Forever stamp. Commemorating the August 21, 2017, solar eclipse, it features an image of the March 2006 solar eclipse taken in Libya by frequent Sky & Telescope contributor Fred Espenak, also known as Mr. Eclipse.

In a first for the Postal Service, this stamp actually incorporates two images in one using thermochromic ink. If you rub your fingers over the black Moon disk that's occluding the Sun, it will transform into an image of the full Moon, also by Espenak.

Okay, we'll admit that we're stretching terminology a little when we call Fred Espenak an amateur. At the time when he took that eclipse image, Espenak was working for NASA's Goddard Space Flight Center. But he was being paid for his research on planetary atmospheres and eclipse prediction, not for his photography. His images have appeared in numerous publications, including National Geographic and Newsweek as well as many astronomy magazines. But if getting a few dollars now and then for publication disqualified people from amateur status, there would be no great amateur astronomers at all.

Fred Espenak

Fred Espenak

Regardless of what you call him, Espenak is a passionate, prolific, and highly accomplished photographer of many different kinds of astronomical scenes. Visit The World at Night for a sampling of his work. Espenak also continues to maintain and update his personal website even after retiring from NASA. It is the first place that many people — including S&T editors — go for information about specific eclipses.

Fred Espenak has hosted a webinar on basic eclipse photography, which is available for download on our website. He will be hosting a live webinar on advanced solar-eclipse photography on May 23rd.

To plan for the upcoming eclipse, visit our Eclipse Portal.

The post U.S. Forever Stamp to Feature Amateur Astrophotos appeared first on Sky & Telescope.

Observatory Software from Code Obsession

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Code Obsession
Available through the Apple iTunes Store

Observatory software screenshotCode Obsession unveils Observatory ($79.95), an image management and processing software for Mac computers. Observatory helps you organize, process, and analyze professional astronomical images as well as your own data. The program allows you to search and import raw professional data from NASA and the ESO for research or to process yourself. Observatory supports FITS, SBIG, TIFF, JPG, PNG, or RAW format images, and includes all the tools necessary to calibrate, align, and combine images. The program also has tools to identify the objects in your images, including all the Messier, NGC/IC, PGC, Tycho-2, UCAC4, USNO-A2.0 catalogs. Requires OS X 10.11 or higher.'s New Product Showcase is a reader service featuring innovative equipment and software of interest to amateur astronomers. The descriptions are based largely on information supplied by the manufacturers or distributors. Sky & Telescope assumes no responsibility for the accuracy of vendors statements. For further information contact the manufacturer or distributor. Announcements should be sent to Not all announcements will be listed.

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This Week’s Sky at a Glance, April 28 – May 6

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Moon, Mars, Pleiades, Aldebaran April 27-29, 2017

The waxing crescent Moon returns to the western evening sky, passing Aldebaran and Mars. Which of these two sparks seems to have the deeper color?

Friday, April 28

• As twilight fades in the west, spot Aldebaran and Mars to the lower right of the crescent Moon, as shown here.

Saturday, April 29

• Now the curve of the crescent Moon points far down toward Aldebaran and Mars at dusk, as shown here. And the horns of Taurus, Zeta and Beta Tauri, occupy roughly the same stances with respect to the Moon as Aldebaran and Mars did last night.

Sunday, April 30

• These spring evenings, the long, dim sea serpent Hydra snakes far across the southern sky. Find his head, a rather dim asterism about the width of your thumb at arm's length, in the southwest. (It's lower right of Regulus by about two fists at arm's length.) His tail reaches all the way to Libra rising in the southeast. Hydra's star pattern, from forehead to tail-tip, is 95° long.

Monday, May 1

• As twilight fades, look above the crescent Moon in the west for Pollux and Castor, and a similar distance left of the Moon for Procyon.

• It's May now. But wintry Sirius still twinkles very low in the west-southwest in twilight, far below Procyon. It sets soon after dusk. How much longer into the spring can you keep Sirius in view each evening? In other words, what will be its date of "heliacal setting" as seen by you?

Tuesday, May 2

• At nightfall, the first-quarter Moon forms part of a gigantic curving arc: To the Moon's lower left is Procyon, to its upper right are Pollux and Castor, and continuing way farther right, you can include Menkalinan and then brilliant Capella. These stars alone, minus the Moon, form the Arch of Spring.

Wednesday, May 3

• The waxing gibbous Moon, 1.3 light-seconds away, shines near Regulus, 79 light-years away. Regulus is the bottom star of the Sickle of Leo, marking Leo's forefoot.

Thursday, May 4

• The moon now shines under the belly of Leo — with Regulus to its right, Algieba a little farther to its upper right, and Denebola a lot farther to the Moon’s upper left.

Friday, May 5

• Now the Moon is under Leo's tail star, Denebola (by about a fist at arm's length). To the Moon's lower left is bright Jupiter, with Spica about half again farther on.

Saturday, May 6

• The Moon tonight forms a gently curving arc with, to its lower left, bright Jupiter and then Spica. Look between the Moon and Jupiter for 3rd-magnitude Porrima (Gamma Virginis), a fine, close telescopic double star.

• Summer is more than six weeks away, but the Summer Triangle is beginning to make its appearance in the east, one star after another. The first up in view is Vega. It's already visible low in the northeast as twilight fades.

Next up is Deneb, lower left of Vega by two or three fists at arm's length. Deneb rises about an hour after Vega does, depending on your latitude.

The third to rise is Altair, which shows up far to their lower right around midnight.


Want to become a better astronomer? Learn your way around the constellations! They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.

This is an outdoor nature hobby. For an easy-to-use constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential guide to astronomy.

Pocket Sky Atlas, jumbo edition

The Pocket Sky Atlas plots 30,796 stars to magnitude 7.6 — which may sound like a lot, but it's less than one per square degree on the sky. Also plotted are many hundreds of telescopic galaxies, star clusters, and nebulae. Shown above is the Jumbo Edition for easier reading in the night. Larger view. Sample chart.

Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of charts). The basic standard is the Pocket Sky Atlas (in either the original or Jumbo Edition), which shows stars to magnitude 7.6.

Next up is the larger and deeper Sky Atlas 2000.0, plotting stars to magnitude 8.5; nearly three times as many. The next up, once you know your way around, is the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope.

You'll also want a good deep-sky guidebook, such as Sue French's Deep-Sky Wonders collection (which includes its own charts), Sky Atlas 2000.0 Companion by Strong and Sinnott, or the bigger Night Sky Observer's Guide by Kepple and Sanner.

Can a computerized telescope replace charts? Not for beginners, I don't think, and not on mounts and tripods that are less than top-quality mechanically (meaning heavy and expensive). And as Terence Dickinson and Alan Dyer say in their Backyard Astronomer's Guide, "A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand."

This Week's Planet Roundup Jupiter on April 20, 2017

Jupiter rotates fast; Christopher Go took these images only about 20 minutes apart on April 20th. North is up. Note the Great Red Spot's dark center and edges and its wide, long turbulent wake. The North Equatorial Belt (above center) is very active in this region, with many small white outbreaks.

Mercury is hidden deep in the glow of sunrise.

Venus (magnitude –4.7) shines low in the east as dawn brightens. In a telescope it's a crescent, thickening a little every morning. This week it's at greatest brightness.

Mars (magnitude +1.6, in Taurus) is finally sinking away in the western evening twilight after a year-long apparition. Don't confuse it with slightly brighter Aldebaran, twinkling 7° left of Mars early in the week. Aldebaran is lower left of Mars by week's end.

Jupiter (magnitude –2.4, in Virgo) shines brightly in the southeast at dusk. It's highest for telescopic viewing by about 11 p.m. daylight saving time. Spica, just a trace bluer, hangs 9° below it in twilight, and lower left of it by 11 p.m. In a telescope Jupiter shrinks from 44 to 43 arcseconds across this week, as Earth pulls away ahead of it in our faster orbit.

Saturn (magnitude +0.2, in Sagittarius) rises around 11 p.m. and glows highest in the south before dawn. Redder Antares (magnitude +1.0) twinkles 18° to Saturn's right in the early-morning hours.

Uranus is hidden in the sunrise.

Neptune is still too low before dawn.


All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America.

Eastern Daylight Time (EDT) is Universal Time (UT, UTC, or GMT) minus 4 hours.


"This adventure is made possible by generations of searchers strictly adhering to a simple set of rules. Test ideas by experiments and observations. Build on those ideas that pass the test. Reject the ones that fail. Follow the evidence wherever it leads, and question everything. Accept these terms, and the cosmos is yours."
— Neil deGrasse Tyson, 2014

"Objective reality exists. Facts are often determinable. Vaccines actually stop diseases. Carbon dioxide actually warms the globe. Science and reason are no political conspiracy; they are how we discover reality. Civilization's survival depends on our ability, and willingness, to do so."
— Alan MacRobert, your Sky at a Glance editor

"Facts are stubborn things."
— John Adams, 1770


The post This Week’s Sky at a Glance, April 28 – May 6 appeared first on Sky & Telescope.

Charla en la UCM

eltamiz -

Esta breve entrada es solo para demostraros que no solo estoy vivo, sino vivito y coleando, aunque no escriba (por ahora). Ayer y hoy he dado un par de charlas sobre mecánica cuántica en la Facultad de Ciencias Físicas de la Universidad Complutense de Madrid, como parte de sus seminarios para la asignatura Fundamentos de Física II, gracias a la amable invitación de Vicente, uno de los profesores de la asignatura.

Charla en la UCM

Hay pocas cosas más agradables que charlar sobre Física con gente inteligente, así que me he divertido mucho, como siempre que doy una charla. Además, todo ha sido agradabilísimo: los anfitriones me han tratado como un rey, y los alumnos han sido encantadores. Luego la gente se queja de la “juventud de hoy en día”, jajaja… los de ayer y hoy eran inquisitivos, educados, críticos, inteligentes… una vergüenza, vamos.

Total, que me lo he pasado teta. La guinda del pastel ha sido el alumno (a quien no pregunté su nombre porque soy imbécil, perdóname si lees esto) que ha venido al final a decirme que está haciendo Ciencias Físicas, en parte, por mi culpa y la de El Tamiz. Si ves esto, como te dije en ese momento, no hay nada más emocionante que nadie pudiera decirle a un profesor. Solo por ese comentario daría diez conferencias.

Así que escribir, por ahora, no escribo, pero de vez en cuando intentaré asomar la cabeza para que no penséis que me ha pasado algo. Aprovecho para agradecer a Amparo, a Vicente y al resto de mis anfitriones que me hayan permitido pasar un rato tan agradable a su lado.

Os aseguro que si algo parecido se repite y es público, os hablaré de ello antes, y no después de haber pasado, pero en este caso no tenía sentido porque era un acto cerrado.

Orbital Path Podcast: Making Gravitational Waves

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The universe sings to us in gravitational waves, and we're starting to listen. Michelle Thaller discusses the discovery of gravitational waves and their unusual effects in her latest astronomy podcast.

LISA Pathfinder

An artist's conception of LISA Pathfinder in space.

Surely one of the most profoundly wonderful and strange ideas in modern physics is that empty space, coupled with time itself, is a thing that can be bent and stretched, and even made to ripple like waves on a pond.

More than 100 years ago, Albert Einstein described gravity as a bending of space and time; anything with mass, from an electron to a supermassive black hole, can bend the universe around it, distorting the measurements of our rulers and clocks in the process. And if this mass happens to move around, spacetime responds to that motion, creating waves of gravity. Incredibly, we exist in a matrix of constantly bending and rippling spacetime.

Luckily for us, it takes a huge amount of energy to generate even a tiny distortion, compared to our human scale. These waves are so small that our most advanced detection devices have just barely been able to tease out signals from one of the most violent events the universe has to offer: two merging, massive black holes. In September 2015, twin detectors that make up the Laser Interferometric Gravitational Wave Observatory (LIGO) shook slightly as the waves from a black hole merger 1.3 billion light-years away reached Earth. This event was the first confirmed detection of a gravitational wave, and by the time it passed us by, the ripple was many, many times smaller than the diameter of a single proton. But that was enough for LIGO.

In this episode of Orbital Path, Professor Jana Levin, a theoretical physicist at Columbia University, tells us the remarkable story about how LIGO came to catch those elusive waves for the first time, turning new eyes, or more accurately, new ears, on to the sound of the universe itself.

If we indeed live in a rippling and undulating universe, are there consequences of gravitational waves we can see, even if the waves themselves were not detected? Marco Chiaberge (STScI) thinks he may have seen just that. Using the Hubble Space Telescope, Chiaberge found a very strange galaxy that appears to be hurling a supermassive black hole out of its core.

Gravitational waves ejected the supermassive black hole in 3C 186

The bright, star-like quasar 3C 186 and its former host galaxy, the faint, extended object behind it, sit at the center of a galaxy cluster. The quasar was probably ejected following a long-ago galaxy merger.
NASA / ESA / M. Chiaberge (STScI / ESA)

Bright, active galaxies are usually powered by black holes millions or billions of times the mass of the Sun in their cores, probably the end result of many smaller black holes colliding and merging over huge timescales. It would make sense, then, that these hugely massive objects would rest right in the center, at the center of mass of their galaxies, everything else spinning around them. But in this case, a black hole with the mass of a billion Suns has been sent careening out of its galaxy at over 4 million mph. Can we all just pause for a moment and consider that? What could possibly have the energy to accelerate a billion solar masses to such immense speeds?

Chiaberge thinks gravitational waves might be the answer. If two huge black holes merge in some rare and unbalanced say, the resulting waves might have gone off asymmetrically, like a bullet fired out of a gun. And the black hole got kicked hard by the recoil.

How else do gravitational waves influence the universe around us? What sorts of exotic objects will we find with the next generation of gravitational wave observatories? We have hardly any idea yet. The universe has been singing to us all along, but only in the last two years have we opened our ears to listen.

Orbital Path is produced by PRX and supported by the Alfred P. Sloan Foundation. Don't miss PRX's other science podcasts: Transistor and Outside Magazine.

The post Orbital Path Podcast: Making Gravitational Waves appeared first on Sky & Telescope.

Inside the June 2017 Issue

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June 2017 IssueWhat is Tabby's Star? Who Discovered the Ring Nebula? Can Life Survive in TRAPPIST-1?

Mysteries abound in astronomy, and not all the questions have answers — yet. Tabby's Star is emblematic of the search for truth. This seemingly ordinary star occasionally undergoes rapid dips and dives in brightness, a phenomenon that Benjamin Montet and discoverer Tabetha Boyajian are still trying to understand. The recent discovery of not one or two, but seven planets around the TRAPPIST-1 star, three of them in the habitable zone, poses interesting questions for those seeking life on other planets. Even seemingly settled questions, such as who discovered the Ring Nebula, can earn a new answer with historical research from S&T Contributing Editor Don Olsen and colleague Giovanni Caglieris. Join the search for answers, and also find explanations for a DIY solar filter, a guide to observing RR Lyrae stars, a rove around the Moon's sunlit poles, and more, in the June 2017 issue of Sky & Telescope.

Feature Articles illustration of TRAPPIST-1 planet sky

Artist’s concept of what the sky might look like from one of the seven known terrestrial planets in the TRAPPIST-1 system.
ESO / M. Kornmesser

Seven Earth-Size Planets Orbit Dim Star
Several of TRAPPIST-1's worlds might have the potential for liquid surface water.
By Camille Carlisle

The Most Mysterious Star in the Galaxy
The strange, dips, and dives of an otherwise ordinary star defy most — but not all — explanations.
By Benjamin Montet & Tabetha Boyajian

The Square Kilometre Array
Spread across two continents, the SKA will be the largest astronomical facility ever built.
By Govert Schilling

Who Discovered the Ring Nebula?
All the books name the wrong "discoverer" for this iconic object.
By Don Olson & Giovanni Maria Caglieris

The Dark Wolf of Summer
Stay up late to track down these absorption nebulae in Lupus.
By Richard P. Wilds

Phantoms of the Deep Sky
Hunt down molecular clouds and other elusive targets.
By Richard Jakiel

Beyond the Printed Page Globular Cluster 47 Tucanae

Globular Cluster 47 Tucanae

Intermediate-Size Black Hole?
Read the full story on the possible black hole lurking in the globular star cluster 47 Tucanae.

Personalized Astronomical Almanac
To find out what's visible in the night sky from your location, visit our Astronomical Almanac.

AAVSO Campaign to Observe Tabby's Star
Find more information on the ongoing campaign to monitor Tabby’s star for any new changes.

Lunar Librations and Phases of the Moon
Librations and other lunar data for June 2017.

ALSO IN THIS ISSUE Saturn on Feb. 26, 2017

Saturn on February 26th, remotely imaged by Damian Peach.

Aim High
Jupiter and Saturn offer good telescopic views for late-night summer observing.
By Fred Schaaf

The Fast Pulse of RR Lyraes
An amateur program tracks the quirks of the oldest standard-candle stars in the universe.
By Alan MacRobert

Peaks of "Eternal" Light
If we ever try to live on the Moon, the best locations will be polar mountains bathed in nearly continuous sunlight.
By Charles Wood

Doodles in the Sky
From sharks to dogs, hats to rings, these night-sky patterns will have you seeking more.
By Sue French

Table of Contents
See what else June's issue has to offer.

The post Inside the June 2017 Issue appeared first on Sky & Telescope.

Are You Ready, Willing, and Abell?

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A cosmic rabbit hole in the tail of Leo will take you to Abell 1367, a wonderland of galaxies more than 300 million light-years from Earth. Step in and lose yourself in the vastness.

Knots of Fuzz in Leo's Tail

Abell 1367 is easy to locate. Look above Denebola in Leo's tail to find 93 Leonis. At least 70 galaxies occupy a 1° circle immediately west of the star.
Bob King; created with Stellarium

Care to join me for a little adventure? There's no better time to stalk external galaxies than on April nights, when the dusty Milky Way hunkers along the east and west horizons, giving center stage to the hordes of spiral, elliptical, and irregular galaxies that cross the meridian from nightfall till the wee hours.

Tucked in the tail of Leo, the Lion, just 5.5° north of the bright star Denebola, you'll find one of the brightest galaxy clusters in the sky, Abell 1367. Also known as the Leo Cluster, this fabulously rich degree of sky contains some 70 major galaxies and many minor ones. On a dark, moonless night, an amateur astronomer with a 10-inch or larger telescope and an hour or two to spare might pick off nearly 100 fuzzy, extragalactic cocoons residing more than 300 million light-years from Earth, or 120 times farther than the Andromeda Galaxy. Far out, man.

Standing at the Edge of Night

Paul Beskeen's photo encompasses all of Abell 1367 and also shows the "jump-off" star, 93 Leonis. Other stars are labeled with magnitudes (decimals omitted). In this and all the photos following, south is up and east to the right to match the field orientation in the larger Dobsonian-style reflectors many amateurs use to look for faint fuzzies. Click the image for a high-resolution view.
Paul Beskeen

The brightest galaxies in the cluster shine around magnitude +12.5 to +13 with the majority a magnitude and more fainter. Sounds challenging, doesn't it? Yes, but take galaxy magnitudes with a grain of stardust. You can almost always see deeper and fainter than you think if you follow these guidelines:

A Deeper Look

I've labeled the brighter NGC ("N"), IC, and UGC galaxies in this wide slice of Abell 1367 that features the busy core and brightest cluster member, NGC 3842. Click the image to see the original, unlabeled photo.
Fritz Kleinhans

  • Dark skies: Start out on the right foot by finding the best, un(light)polluted skies in your area and observe when the target is near the meridian. Abell 1367 culminates in the southern sky around 10 p.m. local time in late April.
  • Dark adaption: Allow at least 15 minutes for your eyes to get "owly."
  • High magnification: Start with low magnification to get oriented, then switch to between 200–250× when you're ready to really dig in. At low powers, you'll only see the brightest galaxies in a cluster. High magnification expands the apparent size of the smaller and fainter objects, allowing the eye to distinguish them from the sky background. Don't go too high, though, or these faint fuzzies will be so spread out, they'll disappear!
  • Averted vision: At night, we use our rod cells to find our way in darkness and soak up photons from dim galaxies. Rods are concentrated away from the center of vision, so to see faint things more clearly, play your gaze around the object rather than staring directly at it. Averted vision will get you at least a magnitude deeper. For more deep-sky observing secrets, read Alan MacRobert's excellent article, Observing Secrets of Deep-Sky Objects Revealed.
At the Root of It All

This artist's conception depicts stars moving around the central supermassive black in a giant elliptical galaxy like NGC 3842.
Gemini Observatory / AURA artwork by Lynette Cook

Most dense galaxy clusters are dominated by elliptical galaxies that grow to titanic sizes through the merger of smaller galaxies members as they fall toward the center of the cluster. Abell 1367 is a little different from other rich clusters in having a sizable population of spiral galaxies. Astronomers interpret the significant number of spirals as a sign of the cluster's relative youth.

That's not the cluster's only stand-out attribute. Its brightest member, the heavyweight 12th-magnitude elliptical galaxy, NGC 3842, possesses one of the largest black holes of any galaxy known with a mass of 9.7 billion suns.

The cluster, along with the Coma Cluster (Abell 1656), form the heart of the Coma Supercluster, the nearest supercluster to our own Virgo Supercluster and the heart of the Great Wall, a huge filament of galaxy clusters and superclusters 500-750 million light-years long said to be one of the largest structures in the observable universe. Abell 1367 forms the Wall's "near" end, with the far end represented by rich clusters in Corona Borealis and Hercules.

Downtown Galaxyville

The core of the cluster will reward observers with 10 or more galaxies dominated by the large elliptical, NGC 3842. See below for annotated version. Abell clusters are named for American astronomer and cosmologist George Abell, who cataloged them from visual inspection of the Palomar Sky Survey plates in the late 1950s. There are 4,073 in total.
Fritz Kleinhans

Finding your way to Abell 1367 couldn't be easier. Center your finder on 4.5-magnitude 93 Leonis, look through a low magnification eyepiece, and you're there! The star is pinned to the cluster's eastern edge. Using the maps, you can star hop from there, stopping at small clumps of galaxies, while edging ever closer to the cluster's core, a magnificently busy downtown where careful scrutiny will repay with a brain-boggling 10 or more galaxies visible in the same 200× field of view.

A Negative View

Click for a high-resolution annotated version to use at the telescope. "C" is short for CGCG. Don't forget — south is up! For a wide-field finder map (with labels) that includes many more galaxies, check out this one by Albert Highe.
Fritz Kleinhans

What I especially like about exploring this cluster are the numerous conveniently placed field stars you can use to navigate this galactic archipelago. The stars also help greatly in pinpointing some of the fainter members. I'll use two or three stars to create a figure, say a triangle or trapezoid, with the sought-for fuzzball at one apex. Once you know exactly where to look, bear down with averted vision, and give it all you've got. Using stars to create makeshift geometric figures will make your hunt easier and more successful.

Galactic Celebs

Rather than make a list of all the galaxies, I've selected a few to highlight. As you might expect, the NGC galaxies are generally larger and brighter than the other cluster members, but not always. Some of the small CGCG objects (Catalog of Galaxies and Clusters of Galaxies) and UGC galaxies (Uppsala Galaxy Catalog) were equally easy to spot.

  • NGC 3837 — Magnitude +13.3. Bright, compact elliptical with a bright stellar nucleus. Touches fainter CGCG 97-143 to the east.
  • NGC 3861 — Magnitude +12.7. Large, easy spiral with a bright, nearly stellar nucleus. I couldn't discern tiny, 15th-magnitude MGC +3-03-94 poking out of its southeastern edge. Note to self — use higher magnification next time.
  • NGC 3860 and companions — Magnitude +13.4. A fuzzy, oval glow with a stellar nucleus located just north of three smaller CGCG galaxies. CGCG 97-114 was faintest, a diffuse patch of haze shining at photographic magnitude +15.3 (+15.3p). Persevere and use averted vision to dig out this rad tetrad.
  • CGCG 97-88 and companions CGCG 97-93 and 97-94 — The first was relatively easy at magnitude +15.2p, but CGCG 97-33 (mag. +15.5p) and CGCG 97-94 about cracked my eyeball at magnitude +15.7. Both appeared as faint wisps at the limit of vision.
  • IC 2951 — Magnitude +13.6. Bright spiral, noticeably elongated east-west with a bright stellar nucleus. A magnitude +13 star touches the eastern end. Smaller, fainter but similarly elongated UGC 6683 lies 1′ to the west. Nice pair!
  • Cluster core / NGC 3842 — In the space of just 10′ at least 11 galaxies pop into view here, dominated by the blobby NGC 3842, a large elliptical with a bright, non-stellar nucleus. I've seen it listed at both magnitude +11.8 and +12.8, so we'll just call it +12. Four small smudges, PGC 36468 (very faint), CGCG 97-90, and NGCs 3841 and 3845 (all easier to spot), ride up along the galaxy's west side.
Super Streak

The galaxy UGC 6697, located about 1.5 million light-years from the core of Abell 1367, is shown here in a composite X-ray (blue) and optical (red & green) image. Supernovae heat the gas to produce X-rays and optical light seen here as the bright cyan glow. The light from stars is shown in red. The faint blue X-ray tail extending to the upper right comes from gas being stripped from the galaxy by its interaction with the hot cluster gas. Over time, this stripping process will remove all the gas from the galaxy, so no new bursts of star formation can occur.
X-ray: NASA / SAO / CXC /M.Sun et al.; Optical: GOLDMine / G. Gavazzi et al.

But the real celebrity in my opinion is the faint, evanescent UGC 6697 that flashes in and out of view like the momentary glimmer of a salmon leaping a waterfall. This magnitude +13.7 needle of light is a peculiar spiral galaxy undergoing a massive wave of star formation. As it plunges toward the center of the cluster at several million miles per hour, cold gas clouds within UGC 6697 are compressed by the hot gas that permeates the cluster. The massive new stars that result from this process will self-destruct as supernovae 10 million years later.

I saw 42 galaxies in Abell 1367 in just one evening in my 15-inch scope, but I'm eager to return because there's are at least 20 more calling my name. Exploring distant clusters whisks our imagination to the furthest reaches of the universe. I wish you happy hours climbing the Great Wall of galactic light in the deepest hours of a dark night.

The post Are You Ready, Willing, and Abell? appeared first on Sky & Telescope.

Why We Marched for Science

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An S&T editor, and his biologist partner, decide where to make a stand, and why.

“OBJECTIVE REALITY EXISTS.” It was a protest sign that I never imagined I would carry on a crowded all-night bus to Washington, DC.

Alan MacRobert and flag-bedraped wife Abby Hafer, the closest they'll ever get to being on the cover of Science magazine.

Alan MacRobert and flag-bedraped wife Abby Hafer, in the closest they'll ever get to being on the cover of Science magazine.

But there I was holding it high with my wife Abby Hafer, an evolutionary biologist and book author, amid a vast, rain-drenched, enthusiastic crowd by the Washington Monument. We listened to speaker after speaker boomingly declare, in many different ways, essentially the message on my sign.

“The very idea of evidence, and logic, and reason, is being threatened by individuals and interests with the power to do real harm,” declared Cara Santa Maria, host of the Talk Nerdy science podcast. Bill Nye, television’s “Science Guy” and head of The Planetary Society, roused the crowd probably more than anyone. “Today we have a great many lawmakers — not just here, but around the world — who are deliberately ignoring and actively suppressing science. Their inclination is misguided. ... Our lawmakers must know and accept that science serves every one of us. Science must shape policy. Science brings out the best in us. With an informed, optimistic view of the future, together, we can — dare I say it — save the world.”

The message behind this unprecedented event, and its 610 sister marches planned around the globe, seemed surreal in its obviousness. An actual, real physical world, which scientists investigate in all their careful ways, exists and works by physical laws unrelated to human wishes, demands, opinions, politics, doctrines, or beliefs. This real physical world is unswayed by wishful thinking, pleas from the distressed, bafflegab from deniers, threats and decrees from the powerful, or anything else to do with humanity’s say-so. It humbles humanity. Yet because of the natural world’s very consistency, we can investigate and understand it reliably, in ever widening breadth and detail and marvelousness — and deduce its deep, undergirding principles. And then put them to practical use.

Science Makes America Great signOr as I said on the other side of my sign, “ ‘Facts are stubborn things.’ –John Adams, 1770.”*

But all the wonderfulness of science comes with a big catch, a nasty sting in the tail. If you “follow the evidence wherever it leads,” it may lead you to things you really didn't want to see.

So it demands the integrity to face reality — no matter how personally upsetting it may be, or how humiliating it may be to admit “Well, I guess I was wrong about that.” Even to yourself.

Valuing reality more than self-confirmation is against human nature. This makes it fragile. The scientific way of thought has appeared and then died out (or been stamped out) in past times and places. And in an internet-based world that enables wacky echo chambers and ideological doubling-down to grow even more than before, fewer people may be interested in accepting the hard bargain that the scientific outlook offers.

As protest crowds go, the people we talked to all day and into the night (exchanging life stories and business cards) were remarkably interesting, thoughtful, and just plain nice. What a crowd. Many attendees were researchers, teachers or students. Many more were fans of science news and of such public intellectuals as E. O. Wilson, Neil deGrasse Tyson, Steven Jay Gould, Richard Feynman, Brian Greene, and Carl Sagan. When I told people where I worked, a surprising number knew of Sky & Telescope.

Many people were there for a particular reason: because they see, all too clearly, a severely climate-changed future if Earth-science denial is not reversed and greenhouse gas emissions are not reduced. It's now well established, but terribly hard to face, that barring great worldwide effort, the next 50 to 150 years will see natural systems disrupted to the point of driving many of the human billions out of uninhabitable Tropical Zone homelands into refugee status or death, and battering the remainder of civilization toward the point of collapse.

The march was officially non-partisan, and in the course of four hours the name “Trump” almost never came from the stage. But it was on many of the signs people carried. President Trump’s declaration that climate change is a "hoax," the administration’s order banning “global warming” or related terms from federal communications, the idea it floated of forbidding NASA to use its satellites to study the Earth, the proposed 42% cut in the Environmental Protection Agency’s scientific research budget, and the threat to pull the U.S. out of the Paris Climate Agreement, were major motivators for the event happening at all.

Abby Hafer "Evolution is Real"

Abby and a very distant cousin.

As our part of the crowd crept past the Environmental Protection Agency offices, people chanted “E-P-A!” A girl who looked about 13 climbed a pedestal there and shouted, “Tell me what democracy looks like!”, and the crowd chanted back “This is what democracy looks like!”

An often-heard, wry chant of the day: “What do we want? Evidence-based policy! When do we want it? After peer review!”

Abby and I came to a resolution. America, the world’s quintessential scientific nation for most of the last century — and the quintessential practical nation since its founding — will not be driven into ignorance and disgrace without a whole lot of us putting up a hell of a fight. We passed the building where the Declaration of Independence is displayed, and we agreed: this is a cause to which we could “pledge our lives, our fortunes, and our sacred honor.” It has begun.


* The full quote, from Adams’s defense summation in the Boston Massacre trials: “Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passions, they cannot alter the state of facts and evidence.”

The post Why We Marched for Science appeared first on Sky & Telescope.

Astronomers March for Science

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On Saturday April 22, 2017, scientists descended upon the nation's capital, as well as hundreds of cities across the U.S. to champion robustly funded and publicly communicated science. Although it was an unambiguously political movement, the event was also billed as nonpartisan — the misuse and misrepresentation of science has occurred on both sides of the aisle. Above all, the March was a celebration of science and the roles it plays in our daily (and nightly) lives.

There were a number of political hotspots to the March for Science — the proposed budget cuts to the National Institutes of Health and the Environmental Protection Agency were one. Astronomy and planetary science, on the other hand, have managed to stay out of budgetary sightlines. Nevertheless, astronomers were as eager to participate in the march as any. Below, share the experience with some of the more celestially minded participants of the March for Science in D.C. and beyond: Casey Dreier from The Planetary Society, Heather Bloemhard from the American Astronomical Society, and John Barentine from the International Dark-Sky Association.

The Planetary Society
Casey Dreier, Director of Space Policy Bill Nye with the March for Science

Bill Nye, CEO of The Planetary Society and self-styled "Science Guy" (center with red bow tie), marches at the head of the March for Science, on April, 22, 2017 in Washington, DC.
Bill O'Leary / The Washington Post via Getty Images

I went to the March for Science in D.C. as a participant. I was there to be part of the experience, to be part of history, and to share that moment with our members and with Bill Nye, the CEO of the Planetary Society (who spoke at the event). It was a cold, miserable, wet day, just raining constantly, and I thought it would affect turn out. But people turned up — they got wet, but they came anyway. We held signs and umbrellas and kept the naïve hope that our rain jackets would keep us dry.

What was moving to me was to see that people weren’t just there to have a good time, they were there to make a statement — they felt that science’s role in shaping public policy was that important. The attendees ranged over a broad spectrum: kids, families, lots of scientists. There were people whose jobs would be affected by recent budget proposals and people who just enjoy learning things about the natural world.

The overall mood was positive and peaceful — wet of course, but everybody was still in a good mood. There was a sense of energy and commitment, a lot of talk about why we were there. Just being present was a powerful thing. We were all there to show this widespread understanding, appreciation, and respect for science and what can be derived from the scientific process.

March for Science participants

Tomas Carbonell, who works for an environmental defense fund geared toward climate change and clean air, pulls his son, Felipe Carbonell-Boon, 4, in a mock NASA space shuttle as thousands gather on the National Mall for the March for Science on Saturday, April 22, 2017, in Washington, DC. 
Jahi Chikwendiu / The Washington Post via Getty Images

It’s crazy that we have to state that so obviously, but there’s a lot of misunderstanding about the process of science. There are all of these different fields — astronomy, environmental science, geology — that share a common approach. Even though Earth science isn’t in the Planetary Society’s purview, at our core we’re a pro-science organization. So if someone attacks the science underlying, say, climate change, they’re actually attacking every other field of science — they’re attacking the method itself. We don’t get to choose the results we like. We may not like the conclusion of a study, but that’s a different conversation. The process itself is reliable, and that’s really what we’re saying with our motto, “Science is Universal.”

At the March for Science, we were there to give everyone a reminder: We can’t just passively expect that science will be accepted and shape policy, we have to actively work to make that connection. And it’s not a partisan thing — science is an incredible tool that has the potential to improve the human condition across the world. So we need to shift from expecting science to be part of the process, to demanding that it be. The long-term effects of the March for Science will be hard to quantify directly, but it’s a powerful thing when we come together in the tens of thousands. Now we hope that the participants will go home and become more engaged in local elections, and share their experience with their friends, family, church, and every part of their social circle.

American Astronomical Society
Heather Bloemhard, John Bahcall Public Policy Fellow

The March for Science / Earth Day 2017 found members of the American Astronomical Society (AAS) standing in the rain in Washington D.C. as speakers addressed the crowd. Healthcare professionals, farmers, and firefighters told us about the importance of basic science research in their fields. Astronauts, scientists, and science communicators from different backgrounds shared their stories and enthusiasm for science. The speakers told us what most of us already know — that science has the power to help and inspire people. For those reasons, and so many more, science is a vital pursuit for our nation that must be accessible to everyone.

Speakers and crowd alike seemed to agree that our policy makers must support science, so that science can in turn best inform policy. For me, the March for Science meant finding solidarity with a group of like-minded individuals, and there’s joy in that. The sentiment “I can’t believe we have to march for this” was fairly common. But times are changing. My concern is that if we don’t figure out how to reach out to the people who disagree with us, we won’t convince them of the value of science. Those are hard conversations, and I don’t know the best way to have them yet. But as I made my way home from the March for Science, one thing was clear to me: scientists and science enthusiasts need to do a better job of branching out and having those conversations, whether it be through advocacy, community outreach, or something else entirely.

International Dark-Sky Association
John Barentine, Program Manager

The Tucson March for Science was held at a small downtown plaza, a venue that appeared packed with about 1,000 people in attendance. As was the case at other sites around the U.S. and the world on April 22nd, the attendees played their part: many wore T-shirts with science-themed slogans and carried signs to the same effect.

International Dark-Sky Association at Tucson's March for Science

John Barentine

A central stage hosted a series of speakers and musical acts beginning at 10 a.m., and there were about three-dozen exhibitors, ranging from local colleges and centers at the University of Arizona to a variety of local nonprofits and political organizations. I put up one of IDA’s pop-up displays on the theme of night-sky heritage; the display garnered a lot of attention and started many conversations.

Our most popular giveaways were postcards advertising the Globe At Night citizen-science program. The project appeared to speak to passers-by — it’s valuable, cutting-edge science in which they can become directly involved. We emphasized to parents and teachers alike the project’s kid-friendly and interactive nature, and that they can see their contribution posted alongside those from all over the world.

There is no Planet B

John Barentine

Many of the folks we talked to were already aware of why we want to keep our skies dark — many even identified Tucson’s dark skies as a key part of the city’s identity. But not everyone knew about the connection between all the astronomy activity in the area and the city’s outdoor lighting code. And some, who weren’t already familiar with the IDA, seemed surprised to learn that an organization like it even exists. Homeowners asked us where they can find dark-sky-friendly lighting (we can help with that!) and teachers were happy to learn of the K-12 educational material we offer.

Overall the event was jubilant. The protest signs were often humorous, but they made their point. Everyone who comes to an event like this knows what’s at stake, and the camaraderie of the like-minded is reassuring in the face of the challenges that the scientific enterprise faces now. The unanswered question in Tucson and other places is: what comes next? Was today’s event a one-off, or the start of a movement?

The post Astronomers March for Science appeared first on Sky & Telescope.

LISA Pathfinder: From Gravitational Waves to Space Dust

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LISA Pathfinder, the technology testbed mission for a future gravitational-wave detector, turns out to be a surprisingly good micrometeoroid hunter.

LISA Pathfinder

An artist's conception of LISA Pathfinder in space.

Sometimes, space missions can have surprising secondary benefits. Putting things in space is an expensive and lengthy task, and scientists and researchers tend to look for innovative ways to get the most out of the few missions that make it beyond the proposal phase and off the launch pad. Now, NASA is looking into just such a possibility: using the European Space Agency's LISA Pathfinder mission to sample the micrometeoroids in the craft's local space environment.

“We've shown we have a novel technique and that it works,” says Ira Thorpe (NASA-Goddard Space Flight Center) in a recent press release. “The next step is to carefully apply this technique to our whole data set and interpret the results.”

LISA Pathfinder: Gravitational-Wave Demonstrator

LISA Pathfinder is designed not as a science mission itself but as key technology demonstrator for what will eventually fly on the full-scale gravitational-wave space mission. Aboard the Pathfinder, two 2-kg (4.4-lb) cubes made of of gold and platinum float in free-fall, nearly motionless with respect to each other.

LISA illustration

In this symbolic illustration, eLISA (the Evolved Laser Interferometer Space Antenna) measures slight ripples in spacetime from a black-hole merger billions of light-years away. eLISA will consist of three stations 5 million km apart, trailing Earth in a solar orbit and linked by laser beams that monitor the slightest changes in their separations.

Eventually, the eLISA (Evolved Laser Interferometry Space Antenna) mission will employ three free-flying versions of LISA Pathfinder in a triangular formation, each spacecraft 5 million kilometers from the other two. The entire structure — larger than the orbit of the Moon — will act as an interferometer, detecting the slightest motions the cubes make in response to passing gravitational waves.

The experiment has already performed admirably during its six-month primary mission, demonstrating a sensitivity five times better than needed for a full-scale eLISA array. Now, with the spacecraft still in good health, researchers are looking to give it a new assignment.

LISA Pathfinder: Micrometeoroid Hunter? LISA Pathfinder in the lab

LISA Pathfinder in the lab.
ESA / CNES / Arianespace / S. Martin

LISA's goal is to maintain a "gravitationally quiet" environment for its gold-platinum cubes, so it counters any opposing force. As such, LISA's entire outer structure acts as a giant micrometeroid shield: When something such as the solar wind disturbs the spacecraft, its micro-newton thrusters gently fire against that force. This helps the cubes remain in true free-fall. And, researchers recently realized, that thruster data could also serve as a record to help characterize the solar environment in terms of space dust and debris.

“Every time microscopic dust strikes LISA Pathfinder, its thrusters null out the small amount of momentum transferred to the spacecraft,” says Diego Janches (NASA-Goddard Spaceflight Center) in a recent press release. “We can turn that around and use the thruster firings to learn more about the impacting particles. One team's noise becomes another team's data.”

LISA Pathfinder micro-thrusters

When LISA Pathfinder is struck by space dust, the spacecraft compensates with its ultra-precise micro-thrusters.

Though tiny, these little particles really pack a punch as they zip along at up to 22,000 mph (36,000 kph), more than 10 times faster than a speeding bullet. NASA has studied micrometeoroid impacts before with its Long Duration Exposure Facility (LDEF), which was deployed in April 1984 by space shuttle Challenger and brought back to Earth by space shuttle Columbia in January 1990. Micrometeoroid impacts have also “sand-blasted” the windows of shuttle orbiters, and tiny impacts and tears have been chronicled on the solar arrays and the exterior of the International Space Station.

But the micrometeoroid population near Earth is probably enhanced by the gravitational influence of the planet itself. LISA Pathfinder orbits 1.5 million kilometers sunward from Earth, at the stable L1 Lagrangian point. (NASA's DSCOVR and Solar Heliospheric Observatory missions occupy this point too, but a good distance from one another.) Researchers hope that what LISA Pathfinder will sample from its orbit will be more representative of the inner solar system environment — data that's crucial for future missions, especially crewed missions to Mars.

The re-purposing of LISA Pathfinder as a micrometeoroid hunter shows that sometimes, one researchers noise is another's data.

The post LISA Pathfinder: From Gravitational Waves to Space Dust appeared first on Sky & Telescope.


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