From the September 2020 issue

Deep-sky observing from Costa Rica

Some of the greatest splendors of the cosmos lie in the Southern Hemisphere.
By | Published: September 28, 2020 | Last updated on May 18, 2023
The southern sky holds numerous treasures, starting with the Southern Cross, Crux (center). The uppermost star in the cross, Gacrux, is the closest red giant star to our Sun at 89 light-years. The great dark Coalsack Nebula lies to the lower left of the cross. Near the right edge of the shot is the Carina Nebula and near the left edge are the bright stars Alpha and Beta Centauri. Yellow-hued Alpha, farthest left, is the closest star system to the Sun, just 4.3 light-years away. 
Yuri Beletsky
If you’re an observer of the skies, you undoubtedly have fond memories of gazing up at Orion and taking in that misty “star” in the middle of the Hunter’s sword. Viewed in a telescope, the Orion Nebula (M42) is a gray-green wonderland of gauzy glow, a nebulous smear of gas that is collapsing down into newborn stars. The brilliant Trapezium, a dazzling gem of four bright stars, acts as the nebula’s centerpiece.

But if you’ve never seen a Southern Hemisphere sky, you’ve never had the “Orion Nebula shock,” as I call it. That’s when you gaze up at M42 and then look over to the east and see the Carina Nebula rising. Much as we may love Orion, the Carina Nebula is factors larger and brighter, in a class by itself.

This past February, I had the great pleasure to accompany a group of Astronomy readers down to Costa Rica for our annual star party, which lets us see the wonders we can never glimpse from the North. We had a small but dedicated group of about 20 this year, all primed to observe the southern skies from a Star Lodge plantation camp north of Puntarenas, on the Gulf of Nicoya, near the country’s western edge. Costa Rica is a splendid place and our site offered an incredible natural adventure in addition to the sky, with daily walks to spy dozens of bird species, howler monkeys, crocodiles, and other critters. We swam, rode horses, and enjoyed the beauty of the locale, which is easy to getto — a mere three-hour flight from Miami.

Our 2020 trip was a joint venture with Astronomy’s travel partner, TravelQuest International. The endeavor was ably led by our maestro of logistics and organization, TravelQuest’s Cody Carter.


Astronomy magazine’s group of travelers enjoyed a splendid week under dark Costa Rican skies. Here, they pose with the new 16-inch Explore Scientific Dobsonian, which provided spectacular views of deep-sky objects, including the Orion and Carina nebulae, and Omega Centauri.

David J. Eicher

A new view

This year, we had the great fortune to raise the bar for our astronomical observing. I transported an Explore Scientific 16-inch Truss Tube Dobsonian telescope down to the site, outfitted with three of Scott Roberts’ gorgeous eyepieces. The 2″ 82° apparent field of view 30mm eyepiece, which we used the most for deep-sky objects, is a perfect eyepiece for the 16-inch, yielding views that were akin to peering into a huge porthole. If you’re looking for a transportable, large-aperture deep-sky scope, I highly recommend this instrument. It was a joy to use and gave me the best views of Southern Hemisphere treasures I’ve ever had. 

The scope was remarkably easy to set up, and collimation, assisted by our HOTECH laser collimator, was similarly simple. Once we had the telescope assembled, I found that I could get it ready for the evening in about 20 minutes. And the views of myriad deep-space objects were mind-blowing. 

Draped in gauzy reflection nebulosity, the Pleiades star cluster in Taurus is one of the closest such star groups to us at 445 light-years. Visible to the naked eye as the Seven Sisters, it is a magnificent binocular target and so large that only low-power scopes show most of its stars. 
Terry Hancock

Familiar favorites

In late February in Costa Rica, the darkening evening twilight brings on a sky shimmering with the bright stars of the winter Milky Way. The first thing we typically turned to was the Orion Nebula — always a show-stopper not only for our own guests, but for the local families and kids who came in one night to have what was, for many, their first view of the distant cosmos. The dark “fish’s mouth” near the nebula’s center, the bright stars of the Trapezium, and the winged shape of the glowing gas extending upward away from the nebula’s base were all apparent at low power, even without proper dark adaption. Our 16-inch Dobsonian showed bright deep-sky objects like M42 as almost photographic in their detail, simply lacking the faint portions visible in long-exposure images and the myriad colors human eye receptors are not structured to detect.

We also explored some other goodies in Orion, such as M78, one of the sky’s best reflection nebulae, which appears as a more-or-less circular haze surrounding bright stars. We next turned to the small, bright planetary nebula NGC 2022, a view of what our solar system may be like in 6 billion to 7 billion years. Near Orion, we wandered over to see two of the gems of Monoceros: the Rosette Nebula and the Cone Nebula.

The Rosette Nebula, a showpiece in astrophotos, is a wreath-shaped emission nebula with a pronounced central hole that contains a bright star cluster, NGC 2244. The nebula’s surface brightness is rather low; that is, individual parts of it appear rather dim, so it glows faintly as a circular, mottled haze. The bright star cluster stands out strongly, however, and the 16-inch scope revealed traces of the dark knots and nebulae intertwined with the bright gas — globules that are condensing down into stars. The Cone Nebula is a relatively easily visible prominent dark nebula, which lies near an associated star cluster, NGC 2264 — sometimes called the Christmas Tree Cluster because of its distinctive shape.

The Star Lodge cabins comfortably offer a base camp for deep-space viewing. 
TravelQuest International
Also nearby in Puppis, we viewed two beautiful star clusters that shouldn’t be missed. Located near each other, M46 and M47 offer a marked contrast. M46 is composed of numerous faint stars, making the cluster appear as a richly appointed cloud of tiny bees. And there’s a bonus: The planetary nebula NGC 2438, a perfect ring shape, appears encased within the cluster. It’s actually a foreground object, but the two make a beautiful eyepiece field. By contrast, M47 is a looser cluster made up of much brighter stars.

Next, we explored the vistas of Taurus. The central portion of this constellation, making up the Bull’s head, is the Hyades star cluster. At 151 light-years, it is one of the closest physically associated groups of stars to us. Aldebaran, the brightest star in the V-shaped group, is a red giant that lies in front of the cluster, 65 light-years away.


Costa Rica’s western coast is a birdwatcher’s paradise.

TravelQuest International
Not far from the Hyades is the other great cluster in Taurus, the Pleiades, famous to naked-eye viewers as the Seven Sisters and so large it is best suited for binocular viewing. Lying 445 light-years off, the Pleiades is another close open cluster, and with the 16-inch scope we glimpsed some of the nebulosity around one of its stars, Merope. This faint reflection nebulosity is dust left over from the cluster’s formation. And we had a terrific view of the Crab Nebula, a supernova remnant left from the A.D. 1054 explosion. It looked remarkably like a photograph in the 16-inch scope, with wiry tendrils of gas branching out from the core.

Seeking southern gems

All the other treats of the winter Milky Way were up there too, and high up, in a nicely dark sky. We waited until late evening, though, for the secret treats to rise — the far-southern gems we cannot see at all back at home. As wonderful as the Orion Nebula is, the Carina Nebula is far larger and brighter. Its three-pronged shape, separated into wedges by a broad dust band, gives it a glowing, spidery appearance in the big scope at low power, the field peppered with both bright and faint stars that show a range of color. The brightest star embedded within one of the wedges of nebulosity is Eta Carinae, one of the most massive stars known, and which has an enigmatic history. During much of the 19th century, it flared up to dazzling naked-eye brightness before fading to near its current magnitude.

Telescopes line up awaiting another clear night at our base camp. 
TravelQuest International
Following the Carina Nebula as Earth turns is the Southern Cross, not to be missed on any trip south. Its topmost star is Gacrux, the closest M-class red giant to the Sun at 89 light-years. The huge, dark Coalsack Nebula covers the lower left quadrant of the Cross. Near the scene’s left edge is one of the area’s most dazzling open clusters, the Jewel Box (NGC 4755). This spectacular star group shone in the 16-inch scope as a tight, colorful bead of bright stars in a rich field. 

Many other bright star clusters and some intriguing nebulae also live in the area. One of the greatest is the cluster IC 2602, sometimes called the Southern Pleiades, which is so bright and scattered, it’s astonishing that more people don’t know about it. If it were in the northern sky, it would be one of the most celebrated deep-sky objects of all.

The centerpiece of Sagittarius is the mighty star-forming region, the Lagoon Nebula. This immense cloud of gas is condensing down into a central star cluster of blue-white, dazzling stars that shine like diamonds in a telescope’s eyepiece. 
Adam Block/Mount Lemmon Skycenter/University of Arizona
As each night progressed, Alpha and Beta Centauri rose, trailing the Cross. It’s a thrill to see these stars for the first time — especially Alpha — even as a bright star in a telescopic field. Alpha Centauri is the closest star system to our Sun and consists of a bright double star that is encircled by a distant third star, Proxima Centauri. At 4.2 light-years, Proxima is a red dwarf and the closest star to the Sun, a shade closer than the double.

And that’s not all. There’s a huge panoply of great stuff that rises after midnight and into the early morning February skies. How about Omega Centauri, the largest and brightest globular cluster in the Milky Way? The view of this mighty sphere of stars in the 16-inch scope was truly jaw-dropping, as if we were viewing it from orbit around the cluster. A short distance north of Omega is the peculiar galaxy Centaurus A, a spectacular showpiece that perhaps foreshadows our own galaxy’s future. The result of a massive collision — two normal galaxies creating a huge, actively star-forming ball with a broad dark band — Centaurus A is astonishing, although somewhat shy with a low surface brightness. The same chaotic future lies ahead with the Milky Way and the Andromeda Galaxy when they merge.

Then, in the early morning hours, came another amazing treat. Most of us northerners are used to seeing the center of the galaxy, Sagittarius and Scorpius, relatively low on the horizon. But stay up long enough on our Costa Rica jaunt and you could see them high in the sky, their dozens of deep-sky treasures perched against inky blackness. The resulting telescopic views, especially in a big scope, were amazing. The Lagoon and Trifid nebulae, the Eagle and Omega nebulae, the Table of Scorpius with brilliant cluster NGC 6231, Scutum and its Wild Duck Cluster, the Bug Nebula, the Rho Ophiuchi region … the list goes on and on and on.

I can tell you that an expedition south to see the skies is one of the most memorable an amateur astronomer can take. We plan to journey once more to Costa Rica for deep-sky observing in February 2021, and again will use the 16-inch Explore Scientific Dobsonian we are so fortunate to now have. See the sidebar for complete details on how you can sign up for the adventure of a lifetime. Not only will the Carina Nebula, the Southern Cross, and Omega Centauri be waiting, but also howler monkeys, dozens of bird species, incredible forests, and many other natural wonders that will make the trip unforgettable. I look forward to traveling with you next year.