Viewing List for June 2019

Placerville, CA Observatory

The Placerville Observatory is Celebrating
Our 14th Year of Public Observing

The Placerville Community Observatory is open every Friday, Saturday, and Sunday night for free.

Stop by between 8:30 and 10:00 pm.

Objects By Scope Size

Object         Type Size Distance   Coordinates

Large Scopes 

NGC3628*   Gal 14’ 35,000,000   LY 11h 20’ +13° 35’
NGC4490** Gal   6’ 25,000,000   LY 12h 31’ +41° 38’
M88*            Gal   6’ 54,000,000   LY 12h 32’ +14° 25’
M90*            Gal   9’ 55,000,000   LY 12h 36’ +13° 10’
M91*            Gal   5’ 54,000,000   LY 12h 35’ +14° 30’
NGC4536** Gal   8’ 50,000,000+ LY 12h 34’ +02° 11’
M104*          Gal   8’ 65,000,000   LY 12h 40’ -11° 37’
NGC4565*   Gal 16’ 31,000,000   LY 12h 36’ +25° 59’
NGC4656*   Gal 19’ 30,000,000   LY 12h 44’ +32° 10’
M3                GC 18’          34,000   LY 13h 42’ +28° 23’
Arp 271**   Gal   5’ 90,000,000    LY 14h 01’ -05° 47’
M5                GC 12’         25,000   LY 15h 19’ +02° 06’
M13              GC 20’         25,100   LY 16h 41’ +36° 27’
M92*            GC 14’         26,700   LY 17h 17’ +43° 08’
M57*            PN   2’           2,300   LY 18h 54’ +33° 02’

4” Refractor Y

Canum Venaticorum Carbon Star 711 LY 12h 45’ +45° 26’

Abbreviations: MS = Multiple Star, EN = Emission Nebula, RN = Reflection Nebula, Gal = Galaxy, GC = Globular Cluster, LY = Light Year, OC = Open cluster, PN = Planetary Nebula, SR = Supernova Remnant, CS = Carbon Star, * = Video imaging optional, ** = Video imaging required

June Object Descriptions

NGC 3628 is a 9.5 magnitude, type SbP peculiar galaxy in the constellation Leo. Seen only 3° from edge-on, this galaxy displays a prominent, warped dust lane. The nuclear core appears mottled and indistinct. The object has a diameter of 78,000 light years and an estimated mass of 135 billion suns. (How does this compare to the Milky Way?)

NGC4490 is a 9.8 magnitude, type SBdP peculiar barred spiral galaxy in the constellation Canes Venatici (CAH-neez veNAT-ih-si). Also known as the Cocoon Galaxy, it forms an interacting pair with nearby NGC4485. With a diameter of only 35,500 light years, this object is seen tilted 65 from face-on and sports a faint tail directed at its fainter companion galaxy.

M88 is a 9.5 magnitude spiral galaxy in the constallation Virgo (VURR-go) that is tilted about 30° from edge-on. Classified as a Seyfert galaxy (possessing a quasar-like core), it displays a relatively bright nucleus that is known to vary in intensity over time, coupled with a spectrum that suggests it is powered by a very active supermassive black hole.

M90 is a 9.5 magnitude spiral galaxy in the constallation Virgo (VURR-go) with a very bright, star-like nucleus and an arc of stars that extends westward from the nucleus. Try to detect hints of a central bar, and S-shaped outer arms.

M91 is a 10th magnitude Barred Spiral galaxy in the constallation Virgo (VURR-go) that occupies a contentious position on the Messier List. The position of the object listed by Messier as a bright nebula in his original observations does not correspond to any object through the eyepiece. After many years of astro-sleuthing, the current intelligence is that Messier was actually observing nearby NGC4548. On a very dark night this object may display a central bar and hints of a hazy halo of stellar arms.

NGC4536 is an 11th magnitude, type SAB barred spiral galaxy in the constellation Virgo (VURR-go). At low magnification, the companion spiral, NGC 4527 may also be glimpsed.

For a real treat for lingering late-night guests, center NGC 4536 in the field of view and recalibrate the scope, then move to celestial coordinates RA 12h 29.1’, Dec +02° 03’. In the center of the field you will glimpse 3C273, the brightest quasar in the sky. Located next to a dimmer foreground star, this object varies between 11th and 12th magnitude. It is a mindboggling 2 BILLION light years away. As veteran observer Sue French wrote, the light we see tonight left this object “when oxygen was just becoming a significant component of Earth’s atmosphere.” How cool is that?

M104 is an 8th magnitude Spiral Galaxy in the constellation Virgo (VURR-go). Commonly known as the Sombrero Galaxy, it is a sure-thing hit with visitors. M104 is easily seen in scopes as small as 4”, and tolerates moderate magnification well. The very bright core seems to illuminate the spiral arm structure and is bisected by a prominent dust lane. In his book, The Messier Objects, Steve O’Meara claimed that, seen at high magnification, the core glowed with a distinct yellow light. What do you see?

NGC4565  is also known as Caldwell 38, and commonly known as the Needle Galaxy, is a large type Sb spiral galaxy found in the constellation Coma Berenices (KOH-mah bera-NEE-seez), Berenices Hair. At a relatively bright 9.6 magnitude, this is a truly outstanding example of a spiral galaxy seen edge-on. A prominent dark lane of dust bisects the narrow galactic disk and bright central core. This galaxy is about 150,000 light years in diameter and has a total mass of more than 200 billion suns. On a very dark night, try to visually detect the dark lane in the 17” scope.

NGC4656 is a 10th magnitude, type SBm barred spiral galaxy in Canes Venatici (CAH-neez- vë-NAT-ih-si). Popularly known as the Hockey Stick Galaxy, the key features are the angled tilt of the disk and the apparent offset of the core, which are significantly distorted by the interaction with its large neighbor NGC 4631. If observing at low magnification look in the same field of view for its neighbor, also seen edge-on.

M3 is an impressive 6th magnitude, globular cluster in the constellation Canes Venatici (CAH-neez vě-NAT-ih-si). Spanning 180 – 200 light years in diameter, this outstanding globular contains nearly 500,000 stars. Globular clusters are home to some of the oldest stars in the universe. Unlike most globular clusters, M3 contains a large population of variable stars. At low magnification through the 17”, look for a hint of color in both the inner core and outer perimeter.

Arp 271 is an interacting pair of spiral galaxies in the constellation Virgo (VUR-go). NGC 5426 is a magnitude 11.4 loose spiral with its outer arms stretching out toward NGC5427. Its oblique angle suggests a short central bar, however computer manipulation shows it as a normal spiral. NGC 5427 is displayed in plan view, showing off its pair of spiral arms. The pair is about 130,000 light years from end to end. While the pair may never merge, they will continue their dance for another 100 million years or so. Hint: Look for faint star-forming regions generated by gravitational effects of the passage.

Note: When the light we see tonight left Arp 271 & NGC 5426, Earth still hosted the big dinosaurs, including Spinosaurus, the largest Theropod known.

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