CentaurZ

2 hours ago, Stu said:

These posts would be great in the Celestial Events calendar if you would consider putting them in there too CentaurZ? That way when the event comes around members will be alerted to them.

Actually, Stu, I posted it in the "Celestial Events Heads Up" forum a few minutes before posting it here.  😎

Mercury will appear to transit the disk of the Sun on 2019 NOV 11 for observers in the Americas, Europe, Africa, Near East and New Zealand. This will be the last Mercury transit until 2032, and until 2049 for North Americans.

As with a Solar Eclipse, great care must be taken to protect eyes. If not accompanied by an expert in solar viewing, it may be wise to simply watch online live videos of the transit.

My graphic is for a fictional geocentric observer with X-ray vision. The timings are in Universal Time (UT) and will differ slightly by various amounts for topocentric observers.

Photos and descriptions of the transit would be welcome additions to this thread.

Mercury will appear to transit the disk of the Sun on 2019 NOV 11 for observers in the Americas, Europe, Africa, Near East and New Zealand. This will be the last Mercury transit until 2032, and until 2049 for North Americans.

As with a Solar Eclipse, great care must be taken to protect eyes. If not accompanied by an expert in solar viewing, it may be wise to simply watch online live videos of the transit.

My graphic is for a fictional geocentric observer with X-ray vision. The timings are in Universal Time (UT) and will differ slightly by various amounts for topocentric observers.

Photos and descriptions of the transit would be welcome additions to my similar thread in the forum for Observing-Planetary.

It’s nearly time for my monthly New Moon spotting challenge. I use the term New Moon in its classical sense of one’s first sighting of the Moon after its monthly solar conjunction (Dark Moon). Attempts to spot the less than one-day-old Moon after sunset on August 30^th may prove fruitless for observers north of the tropics, considering the time of the year. Better luck may be had the following evening.

Photos and descriptions of the young crescent Moon late this month would be welcome additions to this thread.

The waning crescent Moon will occult (cover) stars in the Beehive (Praesepe – M44) Cluster for observers in portions of North America including Chicagoland during the predawn hours of Wednesday 2019 AUG 28. Epsilon Cancri is the brightest Beehive star at magnitude +6.3, which is barely in the range for naked eyes. The entire cluster of over a thousand stars appears as a nebulous object to naked eyes in dark skies. Of course, it is better seen with binoculars or a telescope.

The current series of 25 monthly Beehive occultations extends from 2018 MAY 20 to 2019 NOV 2019. However, the large majority are not visible at nighttime from any particular location. The next series will commence on 2026 JAN 05.

The upcoming immersions will occur on the lunar bright limb and emersions on the dark limb. Any observers on a graze path can witness a star winking on and off as lunar hills and valleys pass by. Those between the two paths will see a full occultation.

Photos and descriptions of the occultations would be welcome additions to this thread. If you would like specific occultation or graze predictions for your location, please reply to this post with your longitude, latitude, elevation and time zone.

The waxing gibbous Moon will occult (cover) Saturn for observers in eastern Australia and northern New Zealand during the evening of Monday 2019 AUG 12.

The current series of 14 monthly Saturn occultations extends from 2018 DEC 09 to 2019 NOV 29. However, the large majority are not visible at nighttime from any particular location. The next series will commence on 2024 APR 06

The upcoming immersion will occur on the lunar dark limb and emersion on the bright limb. Any observers on a graze path can witness the star winking on and off as lunar hills and valleys pass by. Those between the two paths will see a full occultation.

Photos and descriptions of the occultation would be welcome additions to this thread. If you would like specific occultation or graze predictions for your location, please reply to this post with your longitude, latitude, elevation and time zone.

The waxing gibbous Moon will occult (cover) Saturn for observers in eastern Australia and northern New Zealand during the evening of Monday 2019 AUG 12.

The current series of 14 monthly Saturn occultations extends from 2018 DEC 09 to 2019 NOV 29. However, the large majority are not visible at nighttime from any particular location. The next series will commence on 2024 APR 06

The upcoming immersion will occur on the lunar dark limb and emersion on the bright limb. Any observers on a graze path can witness the star winking on and off as lunar hills and valleys pass by. Those between the two paths will see a full occultation.

Photos and descriptions of the occultation would be welcome additions to my similar post in the Observing-Lunar forum. If you would like specific occultation or graze predictions for your location, please reply to my similar post in the Observing-Lunar forum with your longitude, latitude, elevation and time zone.

The annual Perseid Meteor Shower is already underway. The Perseids are usually the finest shower of the year. Normally at the peak more than sixty meteors per hour may be seen by some sharp-eyed folks. The Perseids are debris from the periodic comet 109P Swift-Tuttle.

The shower is expected to peak during the night of 2019 AUG 12-13. Its radiant is in the constellation Perseus. That is the direction toward which the meteor tails point, but the meteors are equally likely to appear anywhere in your sky.

For observers north of the tropics, the meteors appear virtually all night, although most prolifically during the hours before dawn. This year the waxing gibbous Moon near the shower’s peak may provide some interference until it sets during the predawn hours.

Descriptions of the shower or perhaps even lucky photos would be welcome additions to this thread.

Asteroid 15 Eunomia will appear in opposition to the Sun near the Capricornus-Aquarius border on 2019 AUG 12 at magnitude +8.2. That’s beyond naked eye visibility, but it should be seen with small telescopes and good binoculars.

Eunomia is the most massive stony asteroid and was discovered by Italian astronomer Annibale de Gasparis in 1851. It has a mean diameter of 268 km. Eunomia is named after an ancient Greek goddess of law and legislation

Photos and descriptions of Eunomia would be welcome additions to this thread.

Chicago Tribune - today: Light Pollution

It’s nearly time for my monthly New Moon spotting challenge. I use the term New Moon in its classical sense of one’s first sighting of the Moon after its conjunction (Dark Moon) with the Sun. The first opportunity should come with the nearly one-day-old Moon after sunset on August 1^st.

Photos and descriptions of the young crescent Moon this month would be welcome additions to this thread.

Elusive Mercury has commenced its apparition in the predawn eastern sky following its inferior conjunction between Earth and Sun on 2019 JUL 21.

Photos and descriptions of Mercury during this apparition would be welcome additions to this thread.

Is anybody on this message board observing the eclipse? Here in North America it is daytime with the Full Moon beneath the horizon. We're counting on those of you across the pond for reports and pictures. 😎

Indeed, I've been aware for a while that this event would occur with Mars appearing not far from the Sun and setting during twilight. The perspective is even worse from the northern hemisphere. The Beehive stars are all dimmer than magnitude +6 and would be virtually impossible to detect during twilight. Nevertheless, I prepared the graphic seen below.

Thanks, but that doesn't look "dark". It appears to be lit. Of course the side of the Moon that is dark shifts continuously around the lunar surface during the course of a 29.5-day synodic month. Essentially, one side of the Moon continuously faces the Earth, but it rotates relative to the Sun.  When the Moon appears as a crescent, most of its surface facing us is dark, albeit dimly lit by earthshine.

Perhaps you are referring to the "far" side of the Moon, which alternates between dark and light during a synodic month. The same can be said for the "near" side.

The line from Polaris to the Ecliptic (plane of the Earth's orbit) is tilted by about 24˚ from the perpendicular. You would want to be theoretically observing from the North Ecliptic Pole, or the North Pole for the Invariable Plane of the Solar System.

I've written a program similar to what you are seeking based on data from the book "Planetary Programs and Tables from -4000 to +2800" by Pierre Bretagnon & Jean-Louis Simon, with a foreword by Jean Meeus.  Another source I use is "Astronomical Algorithms" by my Belgian friend Jean Meeus. The first book should be quite sufficient for your task. The latter is considerably more comprehensive.

On 12/07/2019 at 13:18, Nigella Bryant said:

Thanks, was just going to post about this but saw you'd already done this, lol. Hope we have clearer skies than when I tried to observe the total, I had 95% to full cloud cover for that. Once again thanks, I'd only just remembered and I've gone down to Devon. I was going to stay until Wednesday morning but if it looks as though it'll be clear I'll travel back Tuesday afternoon, lol. Didn't bring my grab and go scope unfortunately. 

You're welcome, Nigella. I hope you get to see the eclipse.

As I noted above, this month's lunar eclipse will NOT be observable for those of us in North America. Those who can view it are fortunate. The next four lunar eclipses will all occur in 2020 and be merely penumbral, i.e. touched only by the fringe outer portion of the Earth's shadow and barely noticeable.  The next Total Lunar Eclipse will occur on 2021 MAY 26. It will not be visible from Europe.

As I noted above, this month's lunar eclipse will NOT be observable for those of us in North America. Those who can view it are fortunate, and really shouldn't avoid it because it is partial. The next four lunar eclipses will all occur in 2020 and be merely penumbral, i.e. touched only by the fringe outer portion of the Earth's shadow and barely noticeable.  The next Total Lunar Eclipse will occur on 2021 MAY 26. It will not be visible from Europe.

The dwarf planet Pluto will appear in opposition to the Sun in Sagittarius on 2019 JUL 14 at magnitude +14.4. A rather large telescope may be needed to catch this one.

Photos and descriptions of Pluto would be welcome additions to this thread.

It’s nearly time for my monthly New Moon spotting challenge. I use the term New Moon in its classical sense of one’s first sighting of the Moon after its conjunction (Dark Moon) with the Sun. The first opportunity should come with the one-day-old Moon after sunset on July 3.

Photos and descriptions of the young crescent Moon this month would be welcome additions to this thread.

During the evening of Friday 2019 JUN 28, Mars will appear in a straight line with the two brightest stars in Gemini: Pollux and Castor.

During the evening of Friday 2019 JUN 28, Mars will appear in a straight line with the two brightest stars in Gemini: Pollux and Castor.

Ringed Saturn currently rises during the evening as it approaches its opposition from the Sun on 2019 JUL 09, when it will be out all night at stellar magnitude +0.1. Its rings will appear well tilted at +24.4°.

Photos and descriptions of Saturn and its rings would be welcome additions to this thread.

Below is my chart illustrating the positions of Mars and Earth at oppositions from 2018 to 2033.

Indeed in October 2020 Mars will again become rather close and bright, while appearing much higher than in 2018 for northern hemisphere observers. 

A Partial Lunar Eclipse will be seen by many observers with clear skies outside of North America during the night of 2019 JUL 16-17. At maximum eclipse, 65% of the Moon’s diameter will be covered by the Earth’s umbra (dark inner shadow).

Below is my preview graphic for the eclipse as seen against an imaginary blue wall to make the shadow fully apparent. The predicted event timings are in BST (UT+1), but will occur at essentially the same real time for all observers experiencing nighttime. The depicted orientation and Moon altitudes are for an observer in London.

Photos and descriptions of the eclipse would be welcome additions to my similar thread in the Observing-Lunar forum.