Skywatch Line for Monday and Tuesday June 10th and 11th, written by Joe Slomka
This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday June 10th and 11th, written by Joe Slomka.
The Sun sets at 8:33 PM; night falls at 10:49. Dawn begins at 3:01 AM and ends with Sunrise at 5:17.
Monday’s 4½ day-old-moon, rose at 9:01 AM in Cancer, by 9 PM it is 33° high in the West, 30 arc-minutes in apparent size, 21% illuminated and sets Tuesday at 12:16 AM. Tuesday’s Moon shifts to Leo, rises at 10:08 AM, it is 38° high in the West, also 30 arc-seconds, 30% lit and sets at 12:39 AM, Wednesday. Tuesday’s Moon is shy of first quarter and found 3° above Regulus in Leo.
Comets fill gaps for evening observers. Comet 13P/ Olbers is the main attraction. German astronomer Heinrich Olbers discovered it in March of 1815. This year the comet arrives at perihelion (closest to the Sun) on June 30th and is closest to Earth on July 20th. Monday and Tuesday will see it at 7th magnitude by 9 PM, 96% lit, 21° high in the northwest and sets at 12:15 AM. Olbers is traveling through Auriga and Lynx. If you draw a line from Pollux and Casper (in Gemini) and extend it, you will be pointing at the comet for the next two nights.
Dawn planets fill the sky. Saturn is first, in Aquarius, rising at 1:20 AM, 1st magnitude, 17 arc-seconds, by 5 AM it is 34° high in the Southeast. Neptune follows, in Pisces, 10° from Saturn, rising at 1:40 AM, 8th magnitude, appearing 2 arc-seconds and is 33° high. Red planet Mars is next, in Aries, 31° away from Neptune, rises at 2:52 AM, 1st magnitude, 5 arc-seconds, 23° high and appearing 91% lit. Taurus hosts Uranus, Jupiter and Mercury. Uranus, 23° East, rises at 3:51 AM, 5th magnitude, 3 arc-seconds and 12° high. Finally, giant Jupiter, 10° away, rises during Civil Dawn at 4:22 AM, blazes with minus 2nd magnitude, 17° from the Sun and 6° high. All these planets are either fully lit or very close. Jupiter and Mercury are very close to the Sun; observers must take care not to look at the Sun without proper filters. Venus experienced superior conjunction with the Sun on June 4th and remains in solar glare.
By 11 PM, several dim but lovely constellations are sandwiched between brighter Pegasus, Aquarius and Cygnus. One of these is Delphinus, the Dolphin. It looks like a diamond with a tail and replicates a dolphin leaping out of the water. It is found midway between Pegasus’ and Cygnus’ noses.
There are two Greek myths about Delphinus. One states that Arion, a rich poet, was threatened by covetous crewmen, while he was traveling. When he was flung into the sea, he was rescued by a dolphin, which carried the poet to the Greek coast.
Most star names are derived from legends or description. Delphinus is an exception. Its two brightest stars, Alpha and Beta, were the subjects of a practical joke. An Italian astronomer, Niccolo Cacciatore, decided to give them proper names. In Latin, his name was “Nicolaus Venator” He assigned the name “Sualocin” to Alpha, and “Rotanev” to Beta. These names are “Nicolaus Venator” spelled backwards. The practical joke stuck! Today, these are accepted proper names for Alpha and Beta Delphini.
Clear Skies Joe Slomka