It is Spring! Time to Go to the Vibrant Galaxies of Leo I

March 20, 2019 - Comment

Springtime is galaxy time. Solely 30 million mild years away, the Leo I Group and close by Leo Triplet entice the attention with an assortment of brilliant spiral and elliptical galaxies. This trio of galaxies is among the Leo I group’s highlights. Left to proper: NGC 3389 (not a member), NGC 3384 and M105. Sloan

Springtime is galaxy time. Solely 30 million mild years away, the Leo I Group and close by Leo Triplet entice the attention with an assortment of brilliant spiral and elliptical galaxies.

Trio in Leo

This trio of galaxies is among the Leo I group’s highlights. Left to proper: NGC 3389 (not a member), NGC 3384 and M105.
Sloan Digital Sky Survey-II

Welcome to spring! The brand new season begins (or started relying on whenever you learn this) at 5:58 p.m. EDT on March 20th. That is additionally the night time of the total moon, an ideal time NOT observe at this time’s featured galaxies. However the March Moon hurries southward and shortly departs the sky, opening a prolonged dark-sky window starting Friday the 22nd.

Leo the Lion stands excessive within the southeastern sky at dusk this month, flinging galaxies our approach like a clown tossing Tootsie Rolls at a parade. Level your scope in the appropriate course and also you’re sure to catch a number of. We’ll give attention to the Leo I Group, a cluster of galaxies situated about 30 million light-years from Earth. There are a pair issues I like about this group — the members are all on the brilliant facet (round magnitude 10), and you may observe your complete bunch in a single viewing session.

Look in the lion

The Leo I Group is simple to search out to the east of Regulus and simply north of 4th magnitude Rho (ρ) Leonis (circled).

The Leo I Group, additionally known as the M96 Group, is centered on the brilliant Messier galaxies M96 (magnitude 9.three) and M95 (magnitude 9.7), situated four° northeast of 4th magnitude Rho (ρ) Leonis. Varied sources listing wherever from seven to 9 members, however a current deep survey turned up three dozen further faint dwarf galaxies, together with a number of uncommon ultra-diffuse galaxies. The latter are related in measurement to the Milky Method however include solely a fraction as many stars. The hanging Leo Triplet of M65-M66-NGC 3628 lies simply 7.5° east of the core group and could also be bodily related to Leo I; all three have related distances and radial velocities. We’ll add these to the combination, too.

Use this detailed map to paw your approach by way of the Leo I Cluster. All of the galaxies listed below are members or potential members besides NGC 3389 and NGC 3306. North is up and stars are proven to magnitude 13.5. Click on for a big model.
Chris Marriott’s SkyMap

Middle Rho (ρ) Leonis in your finder and you will have little issue recognizing the M95-96 pair four° north-northeast. Each are barred spirals and match comfortably within the 64x subject of view of my 15-inch Dob. M95 is spherical with a brilliant, compact nuclear area and faint stellar nucleus. At 242x the disk appeared mottled with averted imaginative and prescient, however I could not distinguish both the bar or the faint spiral arms peeling off both facet of the central disk and lengthening to the north and south.

M96 is the most important galaxy within the group. It is related in measurement to the Milky Method, with a diameter of 100,000 light-years. An 11.5-magnitude near-stellar nucleus glares from inside the galaxy’s brilliant, prolonged inside disk. However one thing saved bothering me as my eye roved forwards and backwards throughout the scene. Then it hit me — the inside disk appeared askew, oriented roughly east-west contained in the fainter, north-south elongated outer disk. Aha!

Dizzy spiral

Distorted magnificence: M96 contains a brilliant inside disk ringed by crazy spiral arms. The star-speckled arm extending to the higher proper of the nucleus was faintly seen in my 15-inch scope with averted imaginative and prescient. North is up. To the higher left (northeast) of the nucleus a faint background, edge-on galaxy (orange streak) shines by way of the spiral arm. Giant scope homeowners would possibly see it as a “fuzzy star” in M96’s outer halo.
Adam Block

Gravitational interactions previous and current with different members of the Leo I group have warped M96’s disk and drawn out a spiral arm wealthy with new star-forming areas. With 242x and averted imaginative and prescient, I noticed the brilliant, innermost part of this arm as a faint stub of sunshine extending a brief distance northwest of the nuclear disk. On an evening of excellent seeing, M96 is something purchase stingy on element and makes an important goal for high-magnification exploration.

Subsequent, we come to the “Eyes,” a pleasant shut pairing of the elliptical galaxy M105 and its lenticular neighbor NGC 3384 situated simply 7 arcminutes to the northeast.  Each are practically equally brilliant with magnitudes of 9.7 and 10 respectively. You may also catch a glimpse of faint pretender NGC 3389 (magnitude 12.eight), a faint however unrelated spiral galaxy that is 9.5′ southwest of M105. This tight trio makes an exquisite sight huddled collectively in the identical subject of view at medium and excessive powers.


The engaging trio of galaxies is situated northeast of the M95-M96 duo. North is up.
Sloan Digital Sky Survey-II

Each M105 and NGC 3389 seem clean and diffuse with outstanding near-stellar nuclei. M105 is spherical, whereas NGC 3389 is clearly oval. Deep inside M105’s brilliant core, astronomers have recognized a 200-million-solar-mass supermassive black gap. As you are taking within the view, the invisible beast waits for its subsequent snack to cross the occasion horizon.

Fiddler Crab galaxy

Make sure you spend a while with the intriguing spiral NGC 3389, a background galaxy 75 million mild years distant.
Pan-STARRS1 / CC 2.5 Generic

NGC 3389 instantly struck me as odd. A nub of a factor tipped northwest-southeast and asymmetrically brilliant, its west finish glowed brighter than the east. Later, in finding out photographs of the galaxy, I spotted that the brilliant nuclear area appeared off-center to the west as a result of a big spiral arm extends in the other way just like the claw on a fiddler crab, creating visible asymmetry. What do you see right here? Are you able to discern the chunky arm?

NGC 3377 (magazine. 10.four) lies 1.four° virtually due north of M105 — a bit of nudge of the scope and also you’re there with out want of a map. This elliptical galaxy shows a brilliant, near-stellar nucleus embedded inside a brilliant, elongated inside disk set inside a 5′ x three′ oval haze tipped northeast-southwest. Seven arcminutes northwest, search for NGC 3377A (possible unrelated however seems on some lists), a really faint 2-arcminute, amorphous glow of magnitude 13.6.

Odd couple

NGC 3277, a bunch member, is simple to see subsequent to the faint puff, NGC 3277A, which could even be a member.
Sloan Digital Sky Survey -II

We transfer far afield to a different potential group member, NGC 3299, situated three° southwest of NGC 3377. This one appeared as little greater than a faint, diffuse patch of 14th magnitude, nevertheless it wasn’t troublesome to identify at 64x. Simply 12 arcminutes southeast, I additionally discovered the unrelated galaxy NGC 3306 (magnitude 13.6), a small fuzz tipped northwest-southeast with a faint stellar nucleus.

Galactic smudgery

I made these tough pencil sketches of a number of Leo I and associated galaxies, as seen by way of the 15-inch reflector at 242x.
Bob King

We now swing again east to select up two true group members, NGC 3412 and NGC 3489.  The previous is a 10.5-magnitude barred lenticular galaxy. It is three.6′ x 2′ throughout with a brilliant, compact core set in a clean, hazy lozenge of sunshine that is tilted northwest-southeast. NGC 3489 (magazine. 10.2), situated 2.2° additional east, is one other lenticular with a brilliant, near-stellar nucleus and a brighter nuclear area. It is elongated east-west, although narrower than the opposite members of the group.

If brilliant nuclei and 10th-magnitude sound good to your ears, you may be captivated by the Leo I Group. If you happen to want brighter sights, one thing nearer to the magnificence of the Grand Canyon, shift your scope one other 7° to the east to the Leo Triplet. M66 is the showpiece right here with one outstanding, large spiral arm reaching southward like a bent index finger. A a lot fainter arm extends to the east and north. M65 is a beautiful galactic paramecium with an prolonged brighter core and tiny, faint stellar nucleus.

Triple dose of galactic goodness

End your galactic gambol with the Leo Triplet. Prime: NGC 3628; backside: M66 at left and M65. Click on the picture for a finder map.
Hunter Wilson

You’ll be able to end off the triplet with a midnight snack that, regardless of its identify, is appropriate for carnivores and vegetarians alike — the aptly-named Hamburger Galaxy, NGC 3628. With averted imaginative and prescient and 142x, a darkish lane — the burger — flits out and in of view between both half of the pale bun. All three galaxies match with room to spare in a 1° subject of view. They make for a sight that is sure to high off the night time!

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