Exploring Bright Galaxy Groups in Leo – Sky & Telescope

Every time I watch a TV present or film filmed in pre-COVID instances I cringe at scenes that includes packed eating places, bars and live performance crowds. What was once regular actions now appear so alien. Hopefully, that can change quickly. There is not any denying the best crowd engenders vitality and pleasure; gathering in teams to fulfill and share concepts is the essence of being human. I can not wait to really feel that vibe once more.

Likewise within the sky. Once we come throughout a discipline thick with stars or spilling over with galaxies our thrill-meter goes up. Seeing three, 4, or 5 deep-sky objects in the identical view seems like reaching the summit with a sweeping view of peaks throughout. Grander, actually. With galaxy teams, we’re stellar congregations as much as 1,000,000 or extra light-years throughout, separated by tens of 1000’s to tens of millions of light-years. What magic frames a lot house within the tidy circle of the eyepiece?

We will go to three such teams in Leo, all properly positioned within the southeastern sky round 10 p.m. native time within the latter half of March. The waxing Moon will intrude beginning in regards to the 20th however will get out the way in which once more by month’s finish. My observations have been made with a 15-inch reflector below Bortle 3 skies, rated as rural/suburban transition.

I intentionally chosen brighter teams (and the brighter galaxies inside these teams in some circumstances), so all of those also needs to be seen in an Eight-inch telescope and some in apertures as small as 6-inches.

Whenever you observe these clumps, image them as distant variations of our personal Native Group. Every group can also be a member of both the Leo I or Leo II galactic clouds, bigger assemblages of galaxies at distances of roughly 35 million light-years and 75 million light-years, respectively. Like nested matryoshka dolls these fold into the Virgo Supercluster which is a part of even vaster construction, the Laniakea Supercluster.

NGC 3227 Bunch — Leo II Group

One of many best teams to seek out, the NGC 3227 bunch is positioned ¾° east of 2nd-magnitude Gamma (γ) Leonis, often known as Algieba. In sky, even a 6-inch scope will present two galaxies involved — the spiral NGC 3227 and its companion NGC 3226, a dwarf elliptical. Often known as Arp 94 from astronomer Halton Arp’s Atlas of Peculiar Galaxies, this interacting pair makes for a compelling sight. NGC 3227 is the brighter of the 2 at magnitude 10.three and clearly elongated northwest-southeast with a distinguished near-stellar nucleus.

Use magnifications north of 200× to understand its blazing depth and to image what lurks right here, a supermassive black gap some 14 million instances extra huge than the Solar — greater than thrice the heft of the Milky Approach’s darkish coronary heart.

NGC 3227 is a Seyfert galaxy with an lively, quasar-like nucleus that glints in X-rays on time scales of hours to months. Tidal interactions with NGC 3226 to the northwest have spawned blue knots of star formation inside their frequent envelope. NGC 3226 is about half as giant as its companion and a little bit fainter at magnitude 11.four. At first look it seems spherical however reveals a faint, outer envelope angled northeast-southwest with averted imaginative and prescient. It additionally possesses a vibrant, nonstellar nucleus.

A 3rd a lot fainter member of the group, NGC 3213 (magnitude 13.5, dimension 1.1′ × zero.9′), sits 33′ off to the southwest of the duo on the fringe of Algieba’s glare zone. Use magnifications of 200× and better to catch this midge. One other unrelated, extra distant galaxy, NGC 3222 (magnitude 12.Eight, 1.three′ × 1.1′), lies 12′ west of the NGC 3226-27 pair. All 4 slot in a 1° discipline with room to spare.

NGC 3190 bunch — Leo I group

If NGC 3226-27 is your first cease you do not have to go far to seek out our subsequent batch of furry galactic catkins. The NGC 3190 group seems simply 2° north of Gamma (γ) Leonis on a line to Zeta (ζ) Leonis in a discipline peppered with vibrant telescopic stars starting from magnitude 7.5 to 10.5. This tight clump of 4 galaxies spans simply 17′vast, which suggests you need to use magnifications of 200× or extra and maintain all of them in the identical discipline of view.

The galaxy NGC 3193 (magnitude 10.9, 2.zero′ × 2.zero′) is a traditional elliptical — spherical and fuzzy with a brighter core and near-stellar nucleus. A 9.6-magnitude star pins its northern border. Whereas the spiral NGC 3190 (magnitude 11.1, four.four′ × 1.5′) seems a tad fainter it was my favourite with an clearly elongated disk and a vibrant, prolonged nuclear area that swaddled a bloated, starlike nucleus. NGC 3185 (magnitude 12, 2.three′ × 1.6′) was a small, faint oval oriented northwest-southeast with a stellar core and barely brighter inside disk.

I would hoped to see the barred spiral NGC 3187‘s (magnitude 13.four, three.6′ × 1.6′) wacky spiral arms, flung out on both facet like a swing dancer, however this can be a faint, diffuse object, and one of the best I may do was make out a misty, elongated disk tipped northwest-southeast at 257× with averted imaginative and prescient. Each NGC 3127 and neighboring NGC 3190 exhibited warped disks, proof of tidal interactions frequent amongst galaxies in compact clusters.

NGC 3607 bunch — Leo II group

Situated within the tail of Leo this group has two cores, one centered on NGC 3607 and the second on NGC 3684, some 2.7° to the southeast. NGC 3607, a spiral galaxy and the group’s brightest and member at magnitude 9.9 and four.7′ throughout, kinds a good trio with NGC 3608 (magnitude 10.Eight, three.2′ × 2.6′) and faint NGC 3605 (magnitude 12.three, 1.5′ × 1.zero′) in a north-south line. A fourth member, NGC 3626 (magnitude 11.zero, 2.7′ × 1.9′), lies 50′ to the northeast.

NGC 3607 and 3608 resemble a pair of eyes at first look, however NGC 3607 is clearly the brighter with a dense, luminous core and starlike nucleus set in a barely elongated disk oriented northwest-southeast. The elliptical galaxy NGC 3608 is second canine right here — a little bit smaller and fainter and prolonged east-west. Though NGC 3605, additionally an elliptical, seems to be prefer it belongs to the group because of its proximity to NGC 3607, it is really a lot nearer to us at 33 million light-years, making it a possible member of the Leo I group.

NGC 3626 (magnitude 11.zero, 2.7′ × 1.9′), a real member, sits off by its lonesome 48′ northeast of the primary bunch. It is a vibrant spiral prolonged northwest-southeast with a vibrant, stellar nucleus. When you’re poking round you might also discover one other faint galaxy sharing the sphere with NGC 3607-08, round 20′ to the west. This delicate puff with a brighter core is NGC 3599 (magnitude 12.zero, 2.7′ × 2.1′), a spiral galaxy and one other potential member of the Leo I group.

Transferring east we arrive on the second core, composed of 4 quite dim galaxies that comfortably match inside the sphere of view of my 142× Nagler eyepiece — three in an evenly-space northeast-southwest line with the faintest member, NGC 3691 (magnitude 11.Eight, 1.three′ × 1.zero′), shut by to the southeast. NGC 3686 (magnitude 11.three, three.2′ × 2.5′), a barred spiral, is the brightest and largest member of this engaging group.

In good seeing at 257× I may discern a faint, prolonged nuclear area inside a mottled disk elongated northeast-southwest. A 15.5-magnitude star seems contained in the barred galaxy’s southern edge. The extra tightly-wound spiral, NGC 3684 (magnitude 11.four, three.1′ × 2.1′), shows a brighter core however lacks a stellar nucleus like its neighbor NGC 3681 (magnitude 11.2, 2.zero′ × 2.zero′) instantly southwest.

NGC 3691 was a dab of faint, uncondensed mild. Farther afield, 1° west-southwest of the quartet, you may discover one other group member, NGC 3655 (magnitude 11.7, 1.5′ × 1.zero′) clearly elongated northeast-southwest with a vibrant, prolonged core dotted with a nonstellar nucleus.

Should you’re inquisitive about extra galaxies within the area, reminiscent of the brilliant M105 group and the Leo Triplet, please take a look at my earlier blog and Howard Banich’s article on web page 18 of the April 2021 difficulty of Sky & Telescope. One of many challenges in observing these teams is taking the time to differentiate particulars in what seems to be like simply one other faint fuzzy. That is why destiny positioned galaxies within the spring and fall skies, when temperatures are conducive to spending extra time on the telescope and the dreaded mosquitos are scarce.

Asteroid information

On March 21st at 16:03 UT (12:03 p.m. EDT), the possibly hazardous asteroid 2001 FO₃₂ will attain its minimal distance from Earth of about 2 million kilometers. Measuring between 440–680 meters (1,400–2,200 toes) throughout, this massive object will grow to be as vibrant as magnitude 11.7 on the morning of March 21st because it speeds throughout southern Sagittarius. Touring at round 14′ per hour, chances are you’ll even detect its movement in actual time at magnifications of 200× or extra. The asteroid rapidly fades after the 21st however could be noticed earlier on March 20th in Lupus at magnitude 12.zero. For maps, go to astro.vanbuitenen.nl. Because of its southerly declination it is best seen from the southern U.S.

Then, on March 17th, observers within the southwestern U.S. will witness probably the greatest asteroidal occultations of 2021 when 10.7-magnitude Eight Flora covers a 7.2-magnitude star close to the Hyades in Taurus. Your observations of the occasion might be of nice worth in figuring out particulars of Flora’s form and different parameters. The occultation will last as long as 5 seconds with a 1.Eight-magnitude drop. It will usually be bigger, in keeping with David Dunham, with the International Occultation Timing Association (IOTA), however the star’s 9.06-magnitude companion will stay seen throughout the occultation. You may discover finder charts and full particulars here.

---

Commercial