Friday, July 26
With darkish window between sundown and moonrise, have a look this night at two well-known galaxies: M81 and M82, also referred to as Bode’s Galaxy and the Cigar Galaxy, respectively.
Each lie in Ursa Main, seen within the north after sundown. Tonight, the Large Dipper is standing on its bowl with the lengthy deal with arching upward, on the western aspect of the North Celestial Pole. Ursa Main, like different constellations on this area, is a circumpolar constellation that seems to circle the North Star, Polaris.
Look with a telescope to the decrease proper of the Large Dipper’s bowl this night, about 10° northwest of 2nd-magnitude Dubhe, which marks the higher righthand nook of the bowl. There you’ll discover M81, which glows at seventh magnitude and spans about 20′ by 10′. As a result of it’s so brilliant, this spiral is simple to seek out even with small newbie scopes.
Simply 36′ north of M81 is M82. This irregular disk galaxy is oriented comparatively edge-on from our standpoint, which makes it look thinner and longer — like a cigar. It spans about 9′ by 4′ and is a few magnitude fainter than M81, however nonetheless simply to view in a small scope. In truth, attempt dropping in a low-power eyepiece or trying by way of your finder scope — a large area of view will simply present each galaxies collectively. They don’t seem to be solely apparently shut however are really shut in space, interacting with one another gravitationally after a latest (cosmically talking) shut go. M82 specifically is present process a fervent burst of star formation following the interplay.
Dawn: 5:54 A.M.
Sundown: 8:19 P.M.
Moonrise: 11:27 P.M.
Moonset: 11:59 A.M.
Moon Part: Waning gibbous (66%)
*Occasions for dawn, sundown, moonrise, and moonset are given in native time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. native time from the identical location.
Saturday, July 27
Mercury passes 3° south of Regulus at 8 A.M. EDT. You’ll be able to catch the pair along with brilliant Venus within the western sky shortly after sundown.
About half-hour after sundown, Venus is simply 3° excessive, although its magnitude of –3.9 ought to maintain it comparatively straightforward to identify in case your horizon is obvious. Magnitude 0.6 Mercury is way fainter but in addition a little bit greater — some 5° excessive on the similar time, to Venus’ higher left.
Regulus, Leo’s magnitude 1.4 alpha star, lies simply to Mercury’s higher proper. It must be one of many first stars to come out on this area of the sky as twilight falls, however binoculars or any small scope will make it easier to discover it even earlier than the unaided eye can see it. The broader area of view of the previous (or the finder scope on the latter) ought to present each the star and Mercury on the similar time.
Thought a telescope, Mercury seems simply 35 % lit and spans 9″. Examine that — whilst you can — with Venus, which shows a disk solely barely bigger (10″) however with way more of its floor lit: 97 %, showing practically full.
Final Quarter Moon happens at 10:52 P.M. EDT tonight, setting the stage for comparatively darkish morning skies in only a few days when the Southern Delta Aquariid meteor bathe peaks — in addition to the Perseids in early August.
Dawn: 5:55 A.M.
Sundown: 8:18 P.M.
Moonrise: 11:54 P.M.
Moonset: 1:13 P.M.
Moon Part: Waning gibbous (55%)
Sunday, July 28
After the sky grows darkish this night, flip west to search for the Keystone of Hercules — an asterism drawn from 4 Third- to 4th-magnitude stars: Zeta (ζ), Eta (η), Pi (π), and Epsilon (ε) Herculis. The trapezoid they create lies about two-thirds of the best way alongside a line beginning at magnitude –0.1 Arcturus in Boötes and ending at magnitude 0 Vega in Lyra.
Our goal for tonight — the good globular cluster in Hercules (M13) — lies alongside the keystone’s western aspect, simply 2.5° south of magnitude 3.5 Eta. M13 is taken into account one of the best globular seen within the Northern Hemisphere, and we’ve obtained just a few extra months earlier than it disappears from view because the winter sky totally takes over.
M13 will be seen with out optical help on a darkish night time, nevertheless it actually shines in a telescope. Any scope will do, however as all the time, the larger the higher — scopes round 8 inches or bigger will begin to present construction inside this dense ball of stars, reasonably than making it seem as a fuzzy glow dissolving into pinpricks solely on the edges. In total, the cluster spans 15′ to twenty′ and its a whole bunch of hundreds of stars glow collectively at magnitude 5.8.
These photographing the cluster may web a bonus: The Eleventh-magnitude galaxy NGC 6207 lies simply 40′ south of M13.
Dawn: 5:55 A.M.
Sundown: 8:17 P.M.
Moonrise: —
Moonset: 2:26 P.M.
Moon Part: Waning crescent (44%)
Monday, July 29
The Moon passes 4° north of Uranus at 2 P.M. EDT. You’ll discover the pair within the early-morning skies, some 35° excessive round 4 A.M. native daylight time.
Uranus lies in far western Taurus, about 5.5° south of the easy-to-spot Pleiades star cluster (M45). The ice giant itself is finest noticed with binoculars or a telescope, because it glows at a faint magnitude 5.8. As a better signpost in the event you’re star-hopping, Uranus is a few 1.5° west of a pair of Sixth-magnitude stars: 13 and 14 Tauri.
The planet itself is simply 4″ throughout — massive sufficient, although, to assist differentiate it from background stars in the identical area. Uranus ought to look extra like a tiny disk than a pinpoint star and will seem a flat, grayish in coloration to the attention.
The waning Moon, in the meantime, is a few 4.7° to Uranus’ higher proper (northwest) this morning, simply over the celestial border in Aries. Because it makes its means into Taurus later within the day, our satellite will occult a number of stars — Eta, 27, 17, and 20 Tau — for observers in southeast Asia, Indonesia, and western Australia. In case you stay in these locales, try the Worldwide Occultation Timing Affiliation’s web site for 2024 bright star occultations for extra particulars on the timing and visibility out of your location.
Dawn: 5:56 A.M.
Sundown: 8:16 P.M.
Moonrise: 12:25 A.M.
Moonset: 3:40 P.M.
Moon Part: Waning crescent (33%)
Tuesday, July 30
The Moon continues by way of Taurus at clip, passing 5° north of Mars at 7 A.M. EDT. Some 13 hours later, Luna passes 5° north of Jupiter at 8 P.M. EDT.
Let’s try the scene once more within the early morning, when the Moon lies east of the Pleiades and north of Mars, which itself stands 6° above Aldebaran, the pink large “eye” of the Bull. The Purple Planet glows at magnitude 0.8, spanning 6″ on the sky and sitting simply 10′ or so from Fifth-magnitude Omega (ω) Tau. The Moon is now a 26-percent-lit waning crescent, with solely its western limb illuminated.
To the decrease proper of each Mars and the Moon is magnitude –2.1 Jupiter. The mighty king of planets spans 35″ and is flanked by its Galilean moons: Ganymede and Europa to the east, whereas Callisto lies to the west.
The japanese half of the U.S. may also catch sight of Io to Jupiter’s west; the small moon passes into the planet’s shadow simply earlier than 3:40 A.M. EDT, disappearing from view whereas it’s nonetheless some 15″ from the planet’s western limb. The moon will proceed transferring west to east, passing behind the planet itself round 4:45 A.M. EDT. It gained’t reappear till shortly earlier than 5 A.M. MDT, after the Solar has already risen farther east.
In the meantime, take the time additionally to identify Ganymede passing due north of Europa (as the previous is transferring from west to east) round 4:40 A.M. EDT. Sooner than this, Ganymede is barely nearer to Jupiter than Europa; afterward, it pulls farther away.
Dawn: 5:57 A.M.
Sundown: 8:15 P.M.
Moonrise: 1:02 A.M.
Moonset: 4:51 P.M.
Moon Part: Waning crescent (23%)
Wednesday, July 31
The Southern Delta Aquariids peak at the moment with a most zenithal fee of 25 meteors per hour. One of the best time to attempt to spot bathe meteors is within the early-morning hours, when the radiant — the spot on the sky from which meteors seem to streak away — is comparatively excessive and the areas on Earth which might be headed for daylight are rotating into the meteoroid stream.
Strive round 3 A.M. native daylight time, when the radiant stands a little bit greater than 30° excessive within the south. The radiant is within the southwestern areas of Aquarius, simply 6° east of Third-magnitude Deneb Algedi in Capricornus. You’ll be able to count on to see about 12 or so meteors per hour presently although observe the waning Moon may masks a number of the fainter ones. Strive trying a little bit means away from Aquarius, to both aspect, for one of the best probabilities of catching longer brilliant trains left because the meteors vaporize in our environment.
The bathe’s peak additionally coincides with the height of the a lot weaker Alpha Capricornids, whose radiant lies in northwestern Capricornus. That bathe’s most zenithal fee is barely 5 meteors per hour; in the end, it might add a meteor or two per hour to these you see coming from Aquarius.
The Southern Delta Aquariids are medium-fast meteors that zip by way of our environment with a mean velocity of 26 miles (41 kilometers) per second. They’re generated by particles left behind by Comet 96P/Machholz, which orbits the Solar each 5.3 years. The Alpha Capricornids, regardless of originating from an identical area on the sky, are borne of Comet 169P/NEAT, which has a interval of 4.2 years. These are a lot slower-moving meteors, with speeds of 15 miles (24 km) per second.
When you’re ready for meteors to streak overhead, you’ll be able to try the ringed planet Saturn, which glows at magnitude 0.7 in japanese Aquarius. It’s the brightest object on this area of the sky, even outshining magnitude 1.2 Fomalhaut in Piscis Austrinus. Though you’ll wish to scan the sky with unaided eyes to identify meteors, do take a couple of minutes to zoom in on Saturn together with your telescope; the planet spans 19″ and its rings stretch roughly 42″ finish to finish. Its brightest moon, Titan, lies about 1′ east of the planet this morning; we’ll return to take a look at the scene tomorrow morning, when Titan transits Saturn’s southern pole.
Dawn: 5:58 A.M.
Sundown: 8:14 P.M.
Moonrise: 1:48 A.M.
Moonset: 5:56 P.M.
Moon Part: Waning crescent (15%)
Thursday, August 1
Let’s head again to the southern sky early this morning to catch Saturn’s largest and brightest moon, Eighth-magnitude Titan, transiting the far southern areas of the ringed planet’s disk.
The moon begins transiting Saturn’s disk round 1:15 A.M. EDT (so, early on the first for the japanese half of the U.S. solely, and shortly after the planet has risen on the thirty first for these on the West Coast). Titan takes simply over two hours to cross and about an hour into its journey, Tenth-magnitude Dione joins in, a bit farther north (although nonetheless south of the rings). These with very sharp eyesight and good seeing — or taking video-capture frames — may spot Dione’s shadow already on the cloud tops, main the smaller moon throughout.
Within the leadup to the occasion, observers within the japanese half of the U.S. particularly can catch Tenth-magnitude Tethys reappearing from behind Saturn’s japanese limb simply north of the rings moments earlier than 11:45 P.M. EDT (on the thirty first). The planet is just some 7° excessive within the Midwest, so could be tougher to view from this area. Tethys continues transferring east simply above the rings, passing north of Dione (because it’s transferring west beneath the rings) round 12:50 A.M. EDT (on the first within the Japanese time zone solely). By round 1:45 A.M. EDT, Tethys has cleared the sting of the ring system and continues east, approaching equally Tenth-magnitude Rhea, farther east.
For these with bigger scopes and good seeing, an much more difficult statement can be recognizing Thirteenth-magnitude Mimas equally reappearing from occultation behind Saturn simply north of the rings on the planet’s japanese aspect. This happens round 3:35 A.M. EDT.
Dawn: 5:59 A.M.
Sundown: 8:13 P.M.
Moonrise: 2:42 A.M.
Moonset: 6:51 P.M.
Moon Part: Waning crescent (8%)
Friday, August 2
Comet 13P/Olbers is passing by way of southeastern Ursa Main, standing roughly 1.5° from magnitude 3.5 Nu (ν) Ursae Majoris this night.
One of the best time to catch the comet is early night, because the sky begins to develop darkish. An hour after sundown, Olbers remains to be 25° excessive within the west, about midway alongside a line drawn between Denebola, the tip of Leo the Lion’s tail, and Phecda, the decrease lefthand nook of the Large Dipper’s bowl.
Final recorded round seventh magnitude, the comet is reachable however getting more durable for binoculars; it’s nonetheless fairly readily seen in a telescope. The tail ought to seem a bit stubby and fanned out to the north, whereas the southern portion of the coma seems effectively outlined. It ought to nonetheless seem inexperienced in images, because it’s solely only a bit farther from the Solar than Earth (about 1.3 astronomical items, the place 1 astronomical unit — or AU — is the typical Earth-Solar distance). Northern Hemisphere observers will be capable of take pleasure in it for just a few extra months, although it is going to proceed fading at a good clip now, because it reached perihelion (the closest level in its orbit to the Solar) simply over a month in the past and is now heading away from our star.
Olbers may also slide southeast over the approaching weeks, transferring from Ursa Main into Coma Berenices for a rendezvous with the Coma Star Cluster (Melotte 111) round midmonth.
Dawn: 6:00 A.M.
Sundown: 8:12 P.M.
Moonrise: 3:44 A.M.
Moonset: 7:37 P.M.
Moon Part: Waning crescent (3%)
Sky This Week is dropped at you partly by Celestron.
