Planets of the Month: MAY

by Erich Karkoschka

Mercury becomes visible below Venus after May 12th. It rapidly moves past venus on the 21st and will be easily observable well into June. May 21st, Venus (-4.4 magnitude) & Mercury (-.6 magnitude) have a conjunction (very close together), visible about 1 hour after sunset. On May 24th a two-day old Moon join the pair.

Venus is maximum brightness at the beginning of the month and becomes visible before sunset about 45 degrees high. It can even be seen during the afternoon if you know where to look. For example just before 3 pm, look 86 degrees high, essentially overhead. It reverses its prograde motion on the 13th near Elnath and then moves rapidly toward the Sun until it becomes invisible on the 30th. This month is ideal to watch its large, thin crescent in binoculars. By the end of May, it is only 1 percent illuminated. Venus/Mercury conjunction May 21 (see Mercury).

The Moon passes the morning planets from May 12 to the 14th. It will be most impressive on the 23rd and 24th as a thin crescent during dusk near Mercury and Venus. The Moon is full May 7, Last Quarter May 14, New May 22, and First Quarter May 29.

Mars brightens to zero magnitude, even brighter than Saturn. It is 15 degrees east of Saturn in early May, rising to 40 degrees by the end of May. Visible in the early morning sky all month.

Jupiter rises around midnight, dominating the morning sky. Jupiter & Saturn are close all month. A waning Gibbous Moon joins the pair the morning of May 12th.

Saturn follows 5 degrees east of Jupiter all month. This is the closest distance since 2000. They will separate until September and then approach again to .1 degree separation in December. A waning Gibbous Moon joins the pair the morning of May 12th.

Comet PanSTARRS (C/2017 T2) should peak mid May to maybe magnitude 8 or 9. It will be within 1/2 degree of the Cigar Galaxy (M82) May 23/24 in the northern sky.

32 inch Cassegrain Project

International Dark Sky Week Virtual Activities (April 19-26, 2020)

By Jim Knoll

Often referred to as one of the most brilliant and beautiful winter open clusters, M37--my saltshaker cluster--is the brightest of the Auriga clusters (M36, M37,M38) NASA Image — Often referred to as one of the most brilliant and beautiful winter open clusters, M37–my saltshaker cluster–is the brightest of the Auriga clusters (M36, M37,M38)
NASA Image

A few virtual events happening this week (April 19 – 26, 2020) in support of International Dark Sky Week on Facebook Live & You Tube. The Facebook pages below are public pages, so you do not need to have a Facebook account to view them. If you miss any live events, they will probably be available under Facebook Video’s.

Tuesday April 21. 11:30 am Arizona Time (GMT-7 or Pacific Timezone) on the Grand Canyon Conservancy Association (GRCA) Facebook Page (https://www.facebook.com/grandcanyonconservancy/). Ranger Rader Lane will discuss GRCAs journey to become an International Dark Sky Park.

Tuesday April 21. 8:00 pm Arizona Time (GMT-7 or Pacific Timezone) on our TAAA Facebook Page, we will be doing a Virtual Star Party, observing about 12 objects for an hour and half. TAAA Facebook Page: https://www.facebook.com/TucsonAstronomy/. The live event may be located under the Videos section.

Thursday April 23. 12 pm (Noon) Arizona Time on the GRCA Facebook Page. Dean Regas will do a Live Virtual Tour of the Universe. If you don’t immediately see the live video when you go to the Facebook page at the appointed time, look under the Live or Video section of the page.

Friday April 24. 7 – 8:15 pm Arizona Time on the Fred Lawrence Whipple Observatory. A nation-wide livestream Star Party. it will be presented on You Tube. The Whipple webpage is: https://nightsky.jpl.nasa.gov/event-view.cfm?Event_ID=112413

All Week. Log into the International Dark Sky Association International Dark Sky Week page for a schedule of presentations all week long. Many are specific for children and would be good for kids or grandkids. The link to the webpage is: idsw.darksky.org. Once there select schedule.

Solar System

Planets of the Month: APRIL

by Erich Karkoschka

Venus is 40 degrees high at sunset and close to its brightest possible (Magnitude -4.5). After its passage through the Pleiades on the 3rd and 4th, it moves toward Alnath in Taurus. It is visible late into the evening and sets around 10:30 pm. By the end of the month, it is relatively large (39 arch seconds) and 25 % illuminated.

On April 15, the Last Quarter Moon joins the three morning planets in the predawn sky. On April 26, it is closest to brilliant Venus in the evening sky. First Quarter Moon is April 1 and 30, Full Moon April 7, Last Quarter April 14, and New Moon April 22.

Mars is the third planet to rise in the morning sky, following very close to Saturn at the beginning of April but sepertated by about 20 degrees by the end of the month. Mars is at Magnitude +1.

Jupiter rises at 2 am, dominating the morning sky at a magnitude of -2.

Saturn follows Jupiter and is 5 degrees to the east in the morning sky abut the same brightness as Mars at a magnitude of +1.

General Astronomy, Star Parties

Celebrate the Night Sky

by Jim Knoll

Since we don’t have any star parties to talk about and many are at home doing projects, this might be a good time to evaluate your home outdoor lighting to help preserve the dark skies. As many of you know, the International Dark Sky Association (IDA) is located right here in Tucson. Their website is: https://www.darksky.org and they have lots of resources to help you out. Here are some tips to evaluate your own lighting.

– Install lighting only when and where it’s needed.

– Use energy saving features such as timers, dimmers, and motion sensors on outdoor lights. Timers work great to get your attention when they come on.

– Make sure your lighting is shielded so light shines down, not up and does not trespass on your neighbor.

– Educate your friends and neighbors about the importance of good lighting for our health, economy, and environment.

— Artificial light at night can interfere with ecological interactions like predator-prey relationships, interrupts habitat connectivity, influences species’ ability to detect seasonality, and interferes with the human circadian rhythm.

International Dark Sky week is April 19-26, 2020. Join IDA for daily virtual celebrations at: idsw.darksky.org.

Please share with your family and friends.

Spiral galaxies, M77 (face-on) and NGC 1055. Nasa image — Spiral galaxies, M77 (face-on) and NGC 1055.
Nasa image

Astronomical Events

April Astronomy Observing

by Jim Knoll

April has a lot of interesting astronomy events and they are all visible with just your eyes.

April 2 morning. Mars and Saturn are very close in the morning sky (1.5 degrees) with Jupiter another 6 degrees to the upper right. View around 5 or 5:30 am.

April 3 evening. To the west, Venus (brightest object in the night sky in that area) will have a conjunction (get very close) to the Pleiades or 7 Sisters Cluster. In fact, Venus will be in the cluster. View around 7 or 7:30 pm.

Throughout April in the morning around 5 or 5:30 am. Mars (red), Saturn, and Jupiter form a nice line of planets with Mars closest to the horizon and Jupiter furthest with Saturn in the middle. The Moon joins the group April 14 – 16.

April 21-22. The evening or April 21 or even better the morning of April 22 will be the Lyrid Meteor Shower. Toward the east after 10 pm or early in the morning around 5 am look straight up. The shower radiant will be near the star Vega in the constellation Lyra and in the constellation Hercules right next door. Might see up to about 20 meteors per hour.

Sorry, no TAAA Public star parties in April and May. After the Monsoon, we will start them up again. Check our TAAA Website calendar for more info (tucsonastronomy.org) or follow a particular event here on our Facebook Page.

Clear skies and stay safe.

The nebulosity associated with M45 is not the progenitor of the cluster. Instead, it is a nebula through which M45 is passing. NASA Image, Robert Gendler — The nebulosity associated with M45 (Pleiades) is not the progenitor of the cluster. Instead, it is a nebula through which M45 is passing.
NASA Image, Robert Gendler