Venus blazes within the sky above the BlackGEM telescopes at ESO’s La Silla Observatory in Chile. Credit score: Zdeněk Bardon (bardon.cz)/ESO
As February begins, Venus seems low within the western night sky. The good planet stands almost 15° excessive an hour after the Solar goes down and dominates the faint background stars of Pisces the Fish. Though the inside world lies a wholesome 45° east of the Solar, it doesn’t climb excessive as a result of the ecliptic — the obvious path of the Solar throughout the sky that the planets comply with intently — makes a shallow angle to the western horizon after sundown at the moment of 12 months. And, sadly, Venus dips nearer to the horizon because the month progresses.
However not even twilight can hold the brightest planet down. Venus reaches biggest brilliancy at midmonth, when it shines at magnitude –4.9 — totally 10 occasions brighter than its nearest competitor, Jupiter.
That is the month to focus on Venus by means of a telescope as a result of it sports activities a big disk and a delightful crescent form. On Feb. 1, the inside planet seems 32″ throughout and 38 % lit. By the twenty eighth, its diameter has swollen to 48″ whereas the Solar illuminates simply 16 % of its Earth-facing hemisphere.
You should use Venus as a information to discovering Saturn in early February. The ringed planet lies 11° to Venus’ decrease left however shines modestly at magnitude 1.1, so that you may want binoculars to choose it out of the twilight glow. A skinny crescent Moon seems 1° to Saturn’s proper the night of Feb. 1.
Regrettably, Saturn’s low altitude means you gained’t see it clearly in your telescope’s eyepiece. Higher views await after it reappears earlier than daybreak this autumn.
The opposite outer planets fare significantly better on February evenings. Jupiter makes a beautiful sight beneath the Hyades star cluster in Taurus the Bull. Its yellow-white colour contrasts properly with the purple large star Aldebaran, which can appear like a cluster member however truly lies a lot nearer to Earth. The enormous planet shines at magnitude –2.4 and seems far brighter than Taurus’ luminary.
A telescope reveals Jupiter to be a dynamic object with colourful cloud tops arrayed in a sequence of alternating shiny zones and darker belts. Its equatorial diameter at midmonth is 41″, almost 3″ greater than by means of the poles. You’ll additionally wish to hold a watch out for the enormous planet’s 4 shiny satellites — Io, Europa, Ganymede, and Callisto — as they alter relative positions from evening to nighttime.
Mars reached opposition in January and stays a fantastic sight throughout February. Though it dims noticeably this month, the planet glows brighter than magnitude 0.0 and overshadows the in any other case conspicuous stars of Gemini the Twins.
As Mars drifts away from Earth in February, its obvious diameter dwindles from 14″ to 11″. That’s nonetheless sufficiently big to disclose the refined floor markings which have lengthy intrigued each novice {and professional} astronomers. Anticipate moments of regular seeing to see particulars snap into view.
Mercury involves superior conjunction Feb. 9 and stays out of sight all month.
A waning crescent Moon occults the 1st-magnitude star Antares on Feb. 21. Observers within the southern third of South America can have the most effective views. From Buenos Aires, Antares heads behind the Moon’s shiny limb at 7h35m UT and returns to view from behind the darkish limb at 8h32m UT. As a result of Antares is a purple supergiant star, it takes greater than the blink of a watch to vanish and reappear.
The starry sky
I usually confer with the constellation Octans the Octant throughout my planetarium displays. That’s as a result of I like to elucidate the way to discover the South Celestial Pole utilizing Crux the Cross and the Pointer Stars: Alpha (α) and Beta (β) Centauri.
Though Octans doesn’t rank among the many shiny constellations, one a part of it’s pretty simple to acknowledge, at the very least on star charts: the “trapezium” comprised of the celebrities Sigma (σ), Chi (χ), Tau (τ), and Upsilon (υ) Octantis. Don’t confuse this group with Orion’s extra well-known Trapezium Cluster, which lies on the middle of the Orion Nebula (M42). Mathematicians outline a trapezium as a four-sided determine with one pair of parallel sides. The 4 stars in M42 come near this definition, however I believe the 4 in Octans are equally good.
The Octans asterism performs a pivotal position when utilizing the pole finder built-in into some equatorial mounts. These are small telescopes with crosshairs that permit you to align the mount’s polar axis precisely. One member of this stellar quartet — Sigma — offers the Southern Hemisphere’s greatest Pole Star. The precise pole resides a bit greater than 1° from Sigma, so when utilizing such a finder you must estimate the offset between Sigma and the South Celestial Pole. It helps that Sigma, Chi, and Tau kind an arrowhead that factors to the pole. And with a low-power eyepiece, you usually can embrace all three stars and the pole in the identical discipline.
Attempt to see what number of of those stars you will discover with the unaided eye. All lie near the naked-eye restrict. The brightest, Chi, glows at magnitude 5.3, adopted by Sigma at magnitude 5.4, Tau at magnitude 5.5, and Upsilon at magnitude 5.8.
Your probabilities of recognizing the trapezium stars enhance beneath a darkish sky and with a extra southerly location, which locations them larger and thus farther from the dimming brought on by atmospheric extinction.
Star Dome
This map portrays the sky as seen close to 30° south latitude. Positioned contained in the border are the cardinal instructions and their intermediate factors. To search out stars, maintain the map overhead and orient it so one of many labels matches the course you’re going through. The celebs above the map’s horizon now match what’s within the sky.
The all-sky map reveals how the sky seems to be at:10 p.m. February 19 p.m. February 158 p.m. February 28
Planets are proven at midmonth
