Jump to content

  •  

Phil Harrington's Cosmic Challenge Archives

Cosmic Challenge: The Orion Galaxy

Feb 03 2018 10:06 AM | PhilH in Phil Harrington's Cosmic Challenge

You've heard of the Andromeda Galaxy and the Orion Nebula, but how about the Orion Galaxy? Probably not. But would you believe the New General Catalog lists 21 galaxies in Orion, and the Index Catalog adds another 9? That's a pretty respectable tally. Of those 30 Orion galaxies, I find this month's challenge particularly intriguing because it lies so close to everyone's favorite winter deep-sky object, M42. Yet, I am sure that very few observers have seen it.

attachments:
Read story →    12 comments    -----

Cosmic Challenge: The Antennae

May 01 2017 12:45 PM | PhilH in Phil Harrington's Cosmic Challenge

Seven decades ago, while scanning a Palomar Sky Survey plate of the area around brilliant Regulus in Leo the Lion, astronomers Robert Harrington (no relation) and A.G. Wilson noticed a faint blur of light just 1/2° north of the star. They may have thought at first that the glow was just an internal lens flare caused by stray starlight, but it soon became apparent that they had discovered something very real.

attachments:
Read story →    15 comments    -----

Cosmic Challenge: Stephan's Quintet

Oct 01 2017 10:56 AM | PhilH in Phil Harrington's Cosmic Challenge

The canvas on which our picture of the universe is painted relies on the unwavering acceptance of Hubble's Law. Hubble's Law states that a relationship exists between the distance to a galaxy and the speed at which it is receding from us. The farther away a galaxy is, the greater the speed of its recession and farther its spectral lines are shifted toward the red end of the spectrum. For Hubble's Law and the Red Shift Principal to be valid, it must work for not just a few galaxies, but for all. And indeed, it does -- well almost.

attachments:
Read story →    27 comments    -----

Cosmic Challenge: Sharpless 2-301

Feb 01 2019 02:39 PM | PhilH in Phil Harrington's Cosmic Challenge

While a few of Sharpless's entries, such as Sh2-25 (better known as M8, the Lagoon Nebula) and Sh2-49 (M16, the Eagle Nebula), are well known to visual observers, most are among of the most challenging objects to see visually. If you have never made a concerted effort to see some of the lesser known Sharpless objects, then this challenge, Sh2-301 in Canis Major, is a good introduction to the sport.

attachments:
Read story →    4 comments    -----

Cosmic Challenge: Shadow Bands

Aug 03 2017 10:35 AM | PhilH in Phil Harrington's Cosmic Challenge

Enthusiasts think nothing of jetting around the world just to witness the few brief moments of a total solar eclipse. And with good reason, for all who behold the majesty of totality will give impassioned testimony to its unbridled glory. A total solar eclipse is the most beautiful and emotionally charged celestial event of all.

attachments:
Read story →    11 comments    -----

Cosmic Challenge: Pease 1

Oct 01 2016 03:00 AM | PhilH in Phil Harrington's Cosmic Challenge

Of the more than 130 globular clusters gravitationally linked to our Milky Way galaxy, only four are known to contain planetary nebulae.  The best known example of a planetary/globular pairing is Pease 1 found within M15 in Pegasus.  That's this month's Cosmic Challenge.

attachments:
Read story →    3 comments    *****

Cosmic Challenge: North America Nebula (NGC 7000)

Sep 01 2018 05:07 PM | PhilH in Phil Harrington's Cosmic Challenge

The North America Nebula (NGC 7000) is a large expanse of glowing hydrogen gas mixed with opaque clouds of cosmic dust just 3° east of Deneb [Alpha (α) Cygni] and 1° to the west of 4th-magnitude Xi (ξ) Cygni. Famous as one of the most luminous blue supergiants visible in the night sky, Deneb marks the tail of Cygnus the Swan, or if you prefer, the top of the Northern Cross asterism.

attachments:
Read story →    21 comments    -----

Cosmic Challenge: NGC 6886 and NGC 6905

Aug 29 2016 08:52 AM | PhilH in Phil Harrington's Cosmic Challenge

Last month, I offered up two planetary nebulae for smaller apertures. This month, we again hunt for a pair of planetaries. This time, however, we may need a little more oomph to get the job done.

attachments: Attached Image: cosmicchallenge_0916.jpg
Read story →    0 comments    -----

Cosmic Challenge: NGC 6803 and NGC 6804

Aug 07 2016 07:40 AM | PhilH in Phil Harrington's Cosmic Challenge

Here's a two'fer for you, a pair of challenges found within 1° of each other in the constellation Aquila the Eagle. Both of these planetary nebulae present interesting tests for smaller apertures, each in its own way.

attachments:
Read story →    4 comments    -----

Cosmic Challenge: NGC 2419

Mar 04 2018 08:21 AM | PhilH in Phil Harrington's Cosmic Challenge

Probably known better by its nickname the "Intergalactic Tramp" bestowed by Harlow Shapley in 1944, NGC 2419 is unusual among winter's deep-sky objects for many reasons.

attachments:
Read story →    8 comments    *****

Cosmic Challenge: NGC 2363 and NGC 2366

Feb 28 2019 04:59 PM | PhilH in Phil Harrington's Cosmic Challenge

Will the real NGC 2363 please stand up? For years, there has been an ongoing debate over the true identity of the 2,363rd entry in the New General Catalog.

attachments:
Read story →    3 comments    -----

Cosmic Challenge: NGC 147 and NGC 185

Nov 04 2018 08:46 AM | PhilH in Phil Harrington's Cosmic Challenge

M32 and M110 are nice challenges for handheld binoculars. Most amateurs are familiar with them, since they lie in the same field of view of the parent Andromeda Galaxy. But two others, designated as NGC 147 and NGC 185, are not as nearly well known. Both are several degrees to M31's north, across the border in Cassiopeia and feature smaller, fainter disks that are much more challenging to see.

attachments:
Read story →    4 comments    *****

Cosmic Challenge: M51's spiral arms

Apr 30 2019 07:52 AM | PhilH in Phil Harrington's Cosmic Challenge

Of the thousands of spiral galaxies visible through backyard telescopes, one stands above the rest in terms of visual interest: M51, the famous Whirlpool Galaxy in Canes Venatici. Everything adds up in M51's favor. We are seeing it very nearly face-on, its spiral arm halo is bright and peppered with star clouds and vast regions of nebulosity, and it brings with it a friend in the form of a smaller companion galaxy that can even be seen through giant binoculars.

attachments:
Read story →    12 comments    -----

Cosmic Challenge: M13's propeller

Jul 01 2017 09:33 AM | PhilH in Phil Harrington's Cosmic Challenge

In last month's column, we paid a visit to the Moon and the crater pair of Messier and Messier A. This month, we head back out into deep space to examine one of the most spectacular entries in Charles Messier's catalog: M13, the Great Hercules Globular Cluster.

attachments:
Read story →    32 comments    -----

Cosmic Challenge: M109

May 01 2018 05:20 AM | PhilH in Phil Harrington's Cosmic Challenge

Messier did not live to see a second edition of his catalog, but objects 104 through 110 have been added posthumously by others. M109 joined the ranks in 1953, when astronomy historian Owen Gingerich noted Messier's observations of six additional "Méchain objects," now known as M104 through M109.

attachments:
Read story →    5 comments    *****

Cosmic Challenge: Lunar Craters Messier and Messier A

May 31 2017 01:20 PM | PhilH in Phil Harrington's Cosmic Challenge

Summer is in the offing here in the Northern Hemisphere and the longest day of the year is at hand. While many of us enjoy the warmer weather, the dark of night comes late in the evening and leaves all too early the following morning. So while deep-sky observing is limited, we can still enjoy viewing our Moon even if the sky is still bright. Yes, observing challenges await us on our nearest neighbor in space.

attachments:
Read story →    13 comments    *****

Cosmic Challenge: Leo III

Mar 30 2019 09:54 AM | PhilH in Phil Harrington's Cosmic Challenge

A springtime rite of passage started here two years ago. It started in the April 2017 edition of this e-column, when I challenged readers to find the dwarf galaxy Leo I. Leo I is one of many dim dwarf galaxies gravitationally bound to the Milky Way. The fact that its surface brightness rates only 15th magnitude, coupled with its position just 20' north of Regulus makes Leo I a tough challenge to land.

attachments:
Read story →    10 comments    *****

Cosmic Challenge: Leo II

Mar 31 2018 09:54 AM | PhilH in Phil Harrington's Cosmic Challenge

Last April, this column profile the dwarf spheroidal galaxy Leo I, discovered by chance in 1950 by astronomers Robert Harrington (still no relation!) and A.G. Wilson as they were scanning the Palomar Sky Survey. I ended that column saying that "Using the right eyepiece and knowing the field will help you add this dwarf spheroidal to your list of conquered challenges with comparative ease. But don't get too cocky. Spotting its sibling, Leo II is an even greater challenge. But we will leave that for a future column." Well, that future is now.

attachments:
Read story →    4 comments    *****

Cosmic Challenge: Leo I

Apr 01 2017 11:21 AM | PhilH in Phil Harrington's Cosmic Challenge

Seven decades ago, while scanning a Palomar Sky Survey plate of the area around brilliant Regulus in Leo the Lion, astronomers Robert Harrington (no relation) and A.G. Wilson noticed a faint blur of light just 1/2° north of the star. They may have thought at first that the glow was just an internal lens flare caused by stray starlight, but it soon became apparent that they had discovered something very real.

attachments:
Read story →    13 comments    *****

Cosmic Challenge: Jonckheere 900

Mar 04 2017 08:03 AM | PhilH in Phil Harrington's Cosmic Challenge

Few amateur astronomers are familiar with the name Robert Jonckheere. Jonckheere was a French double-star observer who conducted research at a number of observatories over his six-decade career, including the Strasbourg Observatory in France, the Royal Greenwich Observatory in England, as well as McDonald Observatory in Texas.

attachments:
Read story →    9 comments    *****

Cosmic Challenge: Jonckheere 320

Jan 01 2019 06:04 AM | PhilH in Phil Harrington's Cosmic Challenge

On January 22, 1916, while revisiting some of the stars in his Catalog and Measures of Double Stars discovered visually from 1905 to 1916 within 105° of the North Pole and under 5" Separation, French astronomer Robert Jonckheere returned to a vague double in Orion, which he had previously designated as entry number 320. Jonckheere was later to write of this encounter through the 28-inch refractor at the Royal Greenwich Observatory, "I noticed that the object I have catalogued as J 320 is not a double star, but, like J 475, it appears with the larger instrument to be an extremely small bright elongated nebula. As is the case with J 900, this object also appears to be new as a nebula."

attachments:
Read story →    6 comments    *****

Cosmic Challenge: IC 5146 and B168

Oct 29 2016 08:17 AM | PhilH in Phil Harrington's Cosmic Challenge

As a group, emission nebulae, or Hydrogen-II regions, are the most difficult deep-sky objects to see visually. The problem is that they radiate light in very narrow segments of the visible spectrum, with their brightest emissions in the red wavelengths. As luck would have it, the human eye is all but color blind to red light under dim light conditions. Arguably, the only objects more difficult to spot than emission nebulae are the opaque profiles of dark nebulae. These cosmic dust clouds are themselves invisible; we only see their silhouettes against the starry backdrop. No starry backdrop, no dark nebula; it's that simple. And that brings us to this month's double challenge in Cygnus. IC 5146, known to many by its nickname, the Cocoon Nebula, is a taxing patch of glowing gas, while Barnard 168 is a thin, sinuous lane of darkness that seems to start at the nebula and extend far to its northwest.

attachments:
Read story →    6 comments    ***--

Cosmic Challenge: Globular Clusters in the Fornax Dwarf Galaxy

Dec 03 2016 07:13 AM | PhilH in Phil Harrington's Cosmic Challenge

Let's begin this challenge with a riddle. What's big and round, close at hand, and yet nearly impossible to see? If you answered "the Fornax Dwarf Galaxy," then you are correct! The Fornax Dwarf, a dwarf spheroidal system, covers a 17'x13' area of our late autumn sky and lies about 530,000 light years from the Milky Way. That's well within the confines of our Local Group of galaxies. And with a magnitude rating of 9.3, it sounds like it should be bright and easy to see. But when we look its way, it's not there. Even the best photos manage to record only an incredibly dim, elliptical haze peppered by some 19th-magnitude stars!

attachments: Attached Image: 2016-12a.jpg
Read story →    7 comments    *****

Cosmic Challenge: Globular clusters in M31

Dec 01 2018 06:00 AM | PhilH in Phil Harrington's Cosmic Challenge

The Andromeda Galaxy, M31, was probably one of the first galaxies you ever saw first-hand. It was mine. That was all way back in 1969. Since then, I have grown to appreciate it as far more than just the ill-defined oval blur I drew in my logbook. But in 1969, the thought of looking for individual objects within M31 never crossed my mind.

attachments:
Read story →    7 comments    *****

Cosmic Challenge: Glimpsing Vesta

Jun 01 2018 06:34 AM | PhilH in Phil Harrington's Cosmic Challenge

Vesta turns out to be more like a mini-planet than like the chunks of rock most think of as asteroids. Dawn's measurements of the gravity field provided good evidence that Vesta's interior is separated into layers, much like Earth did as the planet was forming. Vesta's dense core - apparently once molten, but now solidified - is composed principally of iron and nickel, just like Earth's. Estimates place it at 125 to 150 miles (200 to 250 kilometers) across. Surrounding that is the mantle, which in turn is covered by the veneer of the crust, about 12 miles (20 kilometers) thick. It is now believed that early on Vesta was likely still accumulating material to become a full-fledged planet when Jupiter's immense gravity intervened, putting a stop to that. As a result, when we look at Vesta, many believe that we are seeing a protoplanet frozen in time.

attachments:
Read story →    10 comments    *****




Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics