THE SOUTHWORTH PLANETARIUM
70 Falmouth Street      Portland, Maine 04103
(207) 780-4249      usm.maine.edu/planet
43.6667° N    70.2667° W  Altitude:  10 feet below sea level Founded
January 1970
2021-2022: CXLIII
"Common sense is the collection of prejudices collected by the age of
eighteen." -Albert Einstein

THE DAILY ASTRONOMER
Friday, July 1, 2022
July Night Sky Calendar (and Quiz) Part I


_____________________________________
No, we didn't make a mistake!
We intended to send tomorrow's DA today because the very first celestial
event will occur on July 1st, a few hours before noon time.
See you again on Tuesday!
______________________________________

Quite a quandary!
The new month begins on a Friday, the day of our weekly quiz.    Do we
offer the first part of the monthly sky calendar or do we post the quiz?
 After a protracted period of contemplation (enough time to flip a coin
only to have it bounce under the couch), we decided....hey, why not offer
both!   How?   It's simple.  We'll send the first part of the night sky
calendar as usual. However, we include blanks in place of the words.
 Your task is to fill in the blanks.

Best of luck to you!      We'll post part two on Tuesday

Named for (1)________________, the month of July is the first full month of
astronomical summer.  We are eagerly anticipating warm nights of ever
increasing duration as the Sun moves slowly but inexorably toward the
autumnal (2)________.
Throughout the month, the Sun will pass through the constellation
(3)___________, the last of the "winter constellations."   Of course, some
of those winter patterns will return this month, albeit in the pre-dawn
eastern sky.    The cycle never stops.


*FRIDAY, JULY 1:   VENUS 4.1 DEGREES NORTH OF ALDEBARAN*
Within the first hours of July, one will see the brilliant planet Venus and
Aldebaran, the brightest star in the constellation (4)________________
almost four degrees apart.  One should experience little difficulty
distinguishing between them as Venus, at magnitude -3.9, will be 83 times
brighter than Aldebaran (magnitude 0.9).      (4)______________ is the
western most of the winter star patterns and so always returns to the early
morning sky this year.

*FRIDAY, JULY 1:  MOON NEAR THE BEEHIVE STAR CLUSTER*
Located in the constellation Cancer the Crab, the Beehive Star Cluster,
also known as (5)__________________, appears close to the waxing crescent
moon (6% illuminated) in the early evening western sky.   As the moon
appears as such a thin crescent, its light won't obscure this cluster.

*SUNDAY, JULY 3:  MOON NEAR (6)_____________________*
The brightest star in Leo the Lion, (6)_________________ appears close to
the waxing crescent moon (17% illuminated) in the western evening sky.
 This regal star represents Leo's heart and also marks the southern point
of its "sickle" asterism.

*MONDAY, JULY 4:   EARTH AT APHELION  (SILVER EVENT!!!)*
 While we're celebrating the war of Colonial aggression, we'll also mark
"Aphelion day," the day on which Earth reaches its point of greatest
distance from the Sun.     At the precise moment of aphelion (3 a.m. EDT),
Earth will be 152.1 million kilometers (94.3 million miles) from the Sun.
   This distance is slightly greater than its average perihelion (shortest)
distance of 147.1 million kilometers (91.2 million miles).      While the
difference does amount to three million miles, the Sun's varying distance
from Earth exerts a negligible effect on our weather.

We also won't see much of a difference in the Sun's size.   The image
below, courtesy of Anthony Ayipmamtis, shows the Sun's apparent size during
aphelion and perihelion.   While this difference was important to the
celestial navigators who used the Sun as one of their markers and so always
needed to know its size, which they termed *semi-diameter*, the Sun will
simply look like the Sun to us.

[image: solar-scenic-aph-peri.jpg]

Earth's distance from the Sun changes because it travels along an orbit
that is elliptical, not circular.     As Earth moves, its heliocentric
distance continually changes.   Our planet reaches perihelion in early
January and aphelion in early July.     Refer to the graphic below,
courtesy of Time-Date.com.     It shows Earth's orbit with the perihelion
and aphelion positions marked.  Note that the orbital elongation is highly
exaggerated.    Earth's orbit is, indeed, elliptical, but appears nearly
circular.

[image: sun-distances.png]

*WEDNESDAY, JULY 6:  FIRST QUARTER MOON*
See the first quarter moon today.   It will rise at 12:27 p.m. and set at
1:36 a.m. tomorrow morning.   The first quarter moon appears (7)____%
illuminated and immediately precedes the (8) __________ ______________
phase.

*SUNDAY, JULY 10:  MOON NEAR ANTARES*
Marking the heart of (9)____________, Antares appears close to the (8)
___________ ____________ moon (86% illuminated) this evening.  Unlike most
stars that appear as non-descript white pinpoints, Antares exudes a
distinctive reddish color because it is an enormous red supergiant.   This
heart star is so enormous,(10)  ______________ suns could fit inside it.
 Antares is known as the "summer red supergiant," as it is prominent in the
summer evening sky.  (11) ______________, in  the constellation
(12)_____________, is known as the "winter red supergiant."  Although
(12)_________ is not currently visible due to its close proximity to the
Sun in our sky, (11)____________ will actually return to the pre-dawn
eastern sky later this month.


ANSWERS
(1) Julius Caesar
(2) equinox
(3) Gemini the Twins (Or Dioscuri)
(4) Taurus the Bull
(5) Praesepe
(6) Regulus
(7) 50
(8) waxing gibbous
(9) Scorpius
(10) 330 million
(11)  Betelgeuse
(12)  Orion


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