Tag Archives: Occultation

Observing Announcement: Spectacular Grazing Occultation Of Aldebaran On 4 March 2017

Greetings, fellow astrophiles!

The following came in from Brad Timerson of ASRAS and the International Occultation Timing Association (IOTA). We had a few posts back in 2014 about an occultation of the star Regulus by asteroid Erigone (on what turned out to be an overcast March 20th. For information about the event and the observing process, see the original CNYO occultation post.

Local observing path for the lunar occultation of Aldebaran on March 4th.

Folks in Rochester and between Syracuse and Binghamton are ideally placed to not only observe the occultation, but also to take data to provide to the IOTA. Information about the occultation, including links to how you can help with the observations, is provided in Brad’s original email below:

I want to alert the membership about this great opportunity (if the weather cooperates!) of seeing a lunar grazing occultation involving a bright star, Aldebaran, along the northern edge of the nearly first quarter moon on the evening of March 4, 2017. In small telescopes, it should be a spectacular sight.

IOTA (International Occultation and Timing Assoc.) has prepared a webpage outlining this event. If you scroll down the page, you will find a section for the Rochester area with a couple of static maps as well as a Google Map for the area. Graze events are dependent on distance from the predicted graze limit as well elevation above sea level. So, the Google Map has been created for the elevation in the Rochester area. (100 feet either way makes little difference)

Main webpage for event: occultations.org/aldebaran/2017march/

Direct link to Google map for approximate elevation in Rochester area: occultations.org/wp/wp-content/uploads/2016/12/500ft.htm

Zoom in to see path through your area. Set the line A to a value of +0.2 km (enter value in box and then press “Click here”). Set line B to –0.1 km. This will produce 2 gray lines, one just north and one just south of the green line. These 2 lines (with the green line in the middle) will mark the best locations for an observing site.

A grazing informational image from the IOTA page.

Based on recent grazes, it appears that you will want to be exactly on the green line shown on the Google map or just barely south of it to see the maximum number of events. Many of the events will be gradual or partial (the star not completely disappearing) because Aldebaran is a large star and at the moon’s distance, won’t be completely covered for some locations.

I plan on observing the graze from a store parking lot (after getting permission) along Rt. 96 near Clifton Springs, NY. Anyone near this area is welcome to join me. I will have more details on my location as the date approaches. I will be videotaping the event using a special camera and video time inserter so that important details of the lunar limb and, possibly, the star, can be determined.

Profile maps of the Aldebaran occultation from the IOTA page.

Central graze time for the Rochester area is 11:17:57 pm on the 4th. You’ll want to be setup well ahead of this time with a clear western horizon. The moon will be about 18° above the horizon. You may see events occur for up to a minute before and after this central graze time. Below is a profile of the lunar limb showing the predicted graze limit as well as a dotted line at about 0.2 km south of the limit. The gray bar graph at the left shows the number of events that can be expected to occur. Time is along the bottom with 11:17:57 pm centered.

Please email me individually (btimerson [_at symbol_] rochester.rr.com) if you’d like information about a specific site along the graze path. Include the latitude, longitude, and elevation of your site taken from Google Earth of the Google map. Also, any other questions you might have can be directed my way.

Here are links to the pages summarizing observations made at the last two grazes. Many observations have YouTube videos available so you can see what to expect.

* www.asteroidoccultation.com/observations/AldebaranGraze_29July2016/
* www.asteroidoccultation.com/observations/AldebaranGraze_19October2016/

Brad Timerson
Newark, NY

CNYO Observing Log: Baltimore Woods, 22 March 2014 (And An Erigone Summary)

Greetings fellow astrophiles!

The often-announced (on this site, anyway) Regulus occultation by asteroid (163) Erigone on the morning of March 20th was a near-wash (no rain, but plenty of cloud cover), with only a few messages being passed around at midnight to see if anyone was even going to try for 2:00 a.m. That said, the International Occultation Timing Association (IOTA) got lots of good press and, with luck, a similarly notable occultation will occur to catch other eyes and instigate the IOTA to prep another big public recording effort. Those who want to relive the non-event can watch the Slooh Community Observatory coverage in the youtube video below.

Then, two days later, Bob Piekiel with his Meade C11 and I with my New Moon Telescope 12.5″ Dob treated two couples at Baltimore Woods to the kind of crystal clear and steady skies you read out but usually never have the good fortune to be out for. With the late March and early April temperatures beginning to melt the high hills of ice and snow around all the big parking lots in the area, the Baltimore Woods setup was a bit solid, a bit slushy, and quite dirty. Our four-person audience arrived early in time to watch the clear skies darken and Jupiter, Sirius, and Betelgeuse first appear in the South/Southwest sky. For the next 90 minutes or so, the observing list included Jupiter (several times at several magnifications, both early in the evening and after the skies had sufficiently darkened to bring out more detail), the Pleiades (M45), the Beehive Cluster (M44), the Orion Nebula (M42), Alcor and Mizar in the handle of the Big Dipper, the Andromeda Galaxy (M31) and its prominent satellites (M32 and M110) very low on the horizon (very likely our last catches of our sister galaxy for several months to come), and even M82 to say that we had, at least, seen the location of the recent supernova (if not a last few photons from it).

In an attempt to help someone remember as many constellations as possible at the Liverpool Public Library lecture a few weeks prior, I retold one of the more memorable tales of the winter star groupings of Orion the Hunter, Taurus the Bull, Canis Major (the big dog), Canis Minor (the little dog), and the Pleiades that I picked up from the excellent Dover book Star Lore: Myths, Legends, and Facts by William Tyler Olcott (which you can even read and download for free in an earlier form at archive.org).

Long story short, the Pleiades (also known as the Seven Sisters or the Seven Virgins) were the target of Orion’s rather significant attention, so much so that in his last run to them, the ever-invasive Zeus placed an equally significant bull in Orion’s path, leaving Orion and his two dogs (Canis Major and Canis Minor) stuck in their tracks. As is apparent from the images below, these four constellations (and one star cluster/Messier Object) are all tightly spaced in the Winter Sky. Better still, the end of Winter even finds these constellations standing on the horizon (instead of upside down in morning Autumn skies), making the picture all the more easily seen. As Orion is second only to the Big Dipper in terms of ease-of-seeing by practically everyone (raised in the tradition of Western Constellation arrangements, anyway), it’s the start constellation from which to find the other three. Canis Major is easily found by its shoulder star Sirius, the brightest start in our nighttime sky. Canis Minor is a leap from Sirius to Procyon, also a prominent star. Taurus the Bull is easily found by its head, the local star cluster known as the Hyades, and its orange-red eye, Aldebaran. The small sisters lie within the boundary of Taurus in a cluster that to the slightly near-sighted might just look like a fuzzy patch (but which, in binoculars, reveals numerous tightly-packed stars).

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Our cast of characters (and nearest neighbors). Image made with Starry Night Pro.

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The prominent stars in their starring roles. Image made with Starry Night Pro.

After packing up around 9:30 (about when the temperatures began to drop precipitously), I managed a single long-exposure image with my Canon T3i of the region above – quite possibly my last good look at the most famous Winter grouping until they appear again in the morning Autumn skies.

2014march29_starringroles

Final scene from Baltimore Woods (with story labels). Click for a larger view.

Regulus Occultation Update #2 – Everyone Else Is Seeing The Event – But Will CNY?

NOTE: For additional information about the Regulus occultation, we’ve three previous posts at cnyo.org that cover the official IOTA (International Occultation Timing Association) press release, a little more info about the event itself, and a previous update from last week. Links are below:

Official IOTA Press Release: www.cnyo.org/2014/02/20/iota-official-press-release-best-and-brightest-asteroid-occultation-ever-to-be-visible-across-new-york-state/

Additional Information: www.cnyo.org/2014/03/04/central-new-york-take-note-and-help-out-the-occultation-of-regulus-by-asteroid-erigone-on-march-20th/

CNYO Update #1: www.cnyo.org/2014/03/12/regulus-occultation-update-weve-got-erigone-on-our-minds/

Greetings fellow astrophiles!

With only 3 full days (and a few hours to either side) left before the occultation of Regulus by Main Belt asteroid Erigone, the news media is starting to feature this event in their always-to-infrequent science snippets (that said, it has been a busy week).

Within the amateur astronomy community came this announcement from the AAVSO (American Association of Variable Star Observers):

Alert Notice 499: Predicted occultation of Regulus

And this ever-thorough analysis from Astro Bob (this is a plug to get you to subscribe to Astro Bob’s RSS feed. His writings are some of the very best in the community):

Asteroid Erigone makes a bright star vanish for 14 seconds – Don’t miss this rare event!

Beyond the larger amateur astronomy community, this announcement and interview (with IOTA members) comes from usatoday.com:

Asteroid to dim a bright star for some in Northeast

Our blogging about the occultation even caught the eyes of Shannon Ash, in-house astrophysicist at the Rachel Maddow Show Blog (I guess we can call this a “link out” instead of a “shout out”), who included a link to our announcement of the IOTA press release.

Week in Geek: This week, a big star ‘winks’

We will await similar “link outs” from Fox News.

So, the good news is that the event is starting to make its rounds in the media. The bad news is, as of Sunday evening, that we in CNY may not get a clear shot at observing the occultation. A smattering of weather predictions from weather.com, News Channel 9, and a youtube post of the forecast from CNYCentral are shown below (the youtube bad news shows up around 3min40sec). We all know that 24 hours in CNY is a LONG time when it comes to weather changes, so we await the predictions on Tuesday (Then Wednesday. Then Wednesday afternoon. Then Wednesday, 11:00 p.m.).

2014mar15_weathercom

Above: Weather predictions from weather.com.

2014mar15_newschannel9

Above: Similar predictions from News Channel 9.

Above: More similar predictions from CNYCentral.