Tag Archives: M44

NASA Night Sky Notes: Dim Delights In Cancer

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. Your tax dollars help promote science! The following article was provided for reprinting by the Night Sky Network in March, 2020.

By David Prosper

Cancer the Crab is a dim constellation, yet it contains one of the most beautiful and easy-to-spot star clusters in our sky: the Beehive Cluster. Cancer also possesses one of the most studied exoplanets: the superhot super-Earth, 55 Cancri e.

Find Cancer’s dim stars by looking in between the brighter neighboring constellations of Gemini and Leo. Don’t get frustrated if you can’t find it at first, since Cancer isn’t easily visible from moderately light polluted areas. Once you find Cancer, look for its most famous deep-sky object: the Beehive Cluster! It’s a large open cluster of young stars, three times larger than our Moon in the sky. The Beehive is visible to unaided eyes under good sky conditions as a faint cloudy patch, but is stunning when viewed through binoculars or a wide-field telescope. It was one of the earliest deep-sky objects noticed by ancient astronomers, and so the Beehive has many other names, including Praesepe, Nubilum, M44, the Ghost, and Jishi qi. Take a look at it on a clear night through binoculars. Do these stars look like a hive of buzzing bees? Or do you see something else? There’s no wrong answer, since this large star cluster has intrigued imaginative observers for thousands of years.

55 Cancri is a nearby binary star system, about 41 light years from us and faintly visible under excellent dark sky conditions. The larger star is orbited by at least five planets including 55 Cancri e, (a.k.a. Janssen, named after one of the first telescope makers). Janssen is a “super-earth,” a large rocky world 8 times the mass of our Earth, and orbits its star every 18 hours, giving it one of the shortest years of all known planets! Janssen was the first exoplanet to have its atmosphere successfully analyzed. Both the Hubble and recently-retired Spitzer space telescopes confirmed that the hot world is enveloped by an atmosphere of helium and hydrogen with traces of hydrogen cyanide: not a likely place to find life, especially since the surface is probably scorching hot rock. The NASA Exoplanet Catalog has more details about this and many other exoplanets at bit.ly/nasa55cancrie.

How do astronomers find planets around other star systems? The Night Sky Network’s “How We Find Planets” activity helps demonstrate both the transit and wobble methods of exoplanet detection: bit.ly/findplanets. Notably, 55 Cancri e was discovered via the wobble method in 2004, and then the transit method confirmed the planet’s orbital period in 2011!

Want to learn more about exoplanets? Get the latest NASA news about worlds beyond our solar system at nasa.gov.

Artist concept of 55 Cancri e orbiting its nearby host star. Find details from the Spitzer Space Telescope’s close study of its atmosphere at: bit.ly/spitzer55cancrie and the Hubble Space Telescope’s observations at bit.ly/hubble55cancrie Credit: NASA/JPL-Caltech
Look for Cancer in between the “Sickle” or “Question Mark” of Leo and the bright twin stars of Gemini. You can’t see the planets around 55 Cancri, but if skies are dark enough you can see the star itself. Can you see the Beehive Cluster?

The Night Sky Network program supports astronomy clubs across the USA dedicated to astronomy outreach. Visit nightsky.jpl.nasa.gov to find local clubs, events, and more!

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).


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


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.


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