At any moment of the day, countless awe-inspiring celestial events are unfolding in the sky. With a universe of options, it can be hard to pin down what to observe, what to look into or what to remember. This column takes a peek at what’s happening in the sky and in the world of astronomy in general to provide a quick list of highlights that can jumpstart your own explorations.
What to observe:
Best seen in April, the Sextans Constellation lies in an area of the night sky populated by Leo, the lion; Hydra, the water snake; and Crater, the cup of the Greek god Apollo. Unlike its mythology-rich neighbors, which are all part of Ptolemy’s original 48 constellations from the 2nd century, the faint Sextans traces its roots back only as far as the late 17th century. Defined by astronomer Johannes Hevelius, the constellation was named to commemorate Hevelius’ own astronomical sextant - an observation tool used to measure star positions - that had been destroyed in a fire a few years before. An equatorial constellation, Sextans covers a 314 square degree area and is visible from 80° north to 90° south. Its brightest star is Alpha Sextantis, which sits on the celestial equator. The white giant has an apparent visual magnitude of 4.48 and lies almost directly south of the brilliant Regulus that boldly shines in the nearby Leo constellation. Other star targets include Beta Sextantis, a blue-white dwarf that undergoes slight variations in magnitude about every 15 days; Gamma Sextantis, a triple star system; Epsilon Sextantis, a yellow-white giant; and the challenging LHS 292, a red dwarf star classified as a flare star because its brightness will suddenly increase and then return to normal. Amateur astronomers hoping to catch a glimpse of LHS 292 will need to use a large telescope. In terms of deep sky offerings, Sextans is home to NGC 3115, which is one of two galaxies referred to as the Spindle Galaxy. This lenticular galaxy seems to lie edge-on to our own much smaller Milky Way, and it contains a supermassive black hole. Other galaxies to explore include the interacting compact spirals NGC 3169 and NGC 3166; Sextans A, a dwarf irregular galaxy with an intriguing square shape; and Sextans B, an irregular galaxy.
What to look into:
Global Astronomy Month
Astronomers Without Borders’ Global Astronomy Month is in full swing and a bounty of activities are available to enjoy. An online highlight for this week is the Messier Marathon, which begins at 18:30 UT on April 11th. During a traditional Messier Marathon, observers haul equipment into the field in an attempt to find as many of the 110 astronomical objects detailed in the famed Messier Catalogue as possible in one night. In this online event, The Virtual Telescope Project will do the heavy lifting for you. To access the marathon, visit www.virtualtelescope.eu/webtv/. Astronomers Without Borders organizes Global Astronomy Month each April to emphasize its motto - “One People, One Sky.” For a complete list of GAM 2015 programs, visit http://astronomerswithoutborders.org/gam2015-programs/program-schedule-2015.html.
April 12 - Yuri’s Night: World Space Party
When it comes to space exploration, April 12th has long held profound significance. It was on that date in 1961 that cosmonaut Yuri Gagarin became the first human in outer space after he blasted off for a 108-minute flight aboard the Soviet space program’s Vostok 1 spacecraft. Although brief, this journey was a monumental milestone that ignited an international passion for space exploration. To commemorate this historic event and ensure that passion continues to thrive, organizers held the first Yuri’s Night on April 12, 2001, and, it has grown every year since. Dubbed a World Space Party, the event is a “global celebration of humanity’s past, present and future in space.” Although the anniversary of Yuri Gagarin’s flight is the foundation of the celebration, it also coincides with another April 12th milestone - the 1981 inaugural launch of NASA’s Space Shuttle, which was the world’s first reusable spacecraft and a catalyst for international cooperation. For more information or a schedule of the hundreds of related parties across the globe, visit www.yurisnight.net.
April 13-18 - International Dark Sky Week
In conjunction with Global Astronomy Month celebrations, the International Dark-Sky Association will kick off International Dark Sky Week on April 13th. The annual campaign seeks to shine a figurative light on the very real problem of light pollution. Held each year since 2003, the week-long awareness event was the idea of Jennifer Barlow, a high school student on a mission to preserve the wonder of the night sky for future generations. The goals for the week are fairly simple: Celebrate the beauty of the stars, raise awareness about the negative effects of light pollution and embolden people to act to reduce the problem. Organizers encourage individuals around the globe to mark the week in a range of ways such as hosting star parties, sharing their thoughts about the issue on social media using #IDSW2015, participating in an IDSW activity or simply visiting the website to find out more about the topic and what changes they can make. For more information on International Dark Sky Week and its associated events, visit http://www.darksky.org/int-l-dark-sky-week-main.