Category Archives: Occultation Campaigns

Probing Echeclus for Coma Activity

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Echeclus, a Centaur averaging 10.7 AU from the Sun, has demonstrated comet-like behavior over the past two decades as it reached its perihelion distance of 5.8 AU in April 2015. From 2005 through 2017, ground based telescopes observed a coma in the vicinity of Echeclus. Shown below are Images of Echeclus and its coma taken by P. Rousselot in March 2006 using the ¸8.2-m ESO Very Large Telescope and FORS 1 instrument.

Figure from Rousselot (2008) – “Echeclus images obtained on March 23 ( top) and March 30 ( bottom). Images B and D are a close-up view of images A and C, with a distinct color scale, to enhance the details near the center of the coma. Note that Echeclus itself is distinct from the center of the coma.” – A&A 480, 543-550 (2008)

This week, RECON has the opportunity to make follow up observations regarding whether any cometary behavior remains. At a distance of 10.2 AU from Earth, the Centaur will be passing in front of an extremely bright magnitude 9.9 star at 08:35 UTC on January 6, 2022, this coming Wednesday night/Thursday morning. Every observing site that is able to record data will help to probe whether there is any cometary gas remaining in the neighborhood of the object thanks to the unusually bright star! The rapid frame rate we can collect will be good for detecting small yet dense structures. By adding all the data together we can put more sensitive limits on the properties of any material near Echeclus. The more sites we have, the more sensitive our limits will be. It is very unlikely that we will have another opportunity to repeat this particular observation so the best of luck to everyone.

For more information on this occultation opportunity, visit the Event Page for (60558) Echeclus.

Prepped for Patroclus and Menoetius

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The NASA Lucy Mission will fly by the binary Trojan asteroid system (617) Patroclus/Menoetius in 2033. Ground-based stellar occultation data is essential both for mission planning and our understanding of minor planets. On Sunday, May 9 at 8:37:55 UT, the shadows of these 113km and 108km asteroids will sweep over the southern US as they occult an 11.5 magnitude star in Scorpius.

Occultation predictions for Patroclus (northern) and Menoetius (southern) showing 3-sigma uncertainties and both fixed (orange) and mobile (purple) observing sites.

To measure this event, roughly 20 teams affiliated with RECON will measure Patroclus from primarily fixed site locations (orange chords) while another 30 teams will measure Menoetius from primarily mobile sites deployed in Texas (purple chords).

Exceptional RECON Opportunity

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On Thursday/Friday night, April 15-16, Hi’iaka (a satellite of Haumea) will be occulting a bright star (magnitude 11.9) with a shadow path centered almost perfectly over the RECON network! The occultation prediction below was updated just this week based upon a successful occultation chord obtained on April 6 at Oukaimeden Observatory in Morocco. This event (starting around 6:30UT on April 16 for locations west of Colorado) is an exceptional science opportunity to better understand and characterize this moon and the Haumea system. We look forward to having all RECON hands on deck to capture this important event!

Occultation prediction for Hi’iaka. Solid black lines is estimated size of object. Red lines are conservative 1-sigma uncertainty estimate, dashed lines are related to the nominal uncertainty of the satellite orbit.

Occultation Season Returns

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The Milky Way and plane of our solar system (the ecliptic) cross in the constellation Sagittarius, which is most prominent in the night sky during the summer months. Panorama by Matt Dieterich.

As many RECON team members have noticed, the frequency of occultation campaigns drops off during the summer months.

Image from Wikimedia Commons

Interestingly, the reason for this has to do with the orientation of our Milky Way Galaxy and the plane of our solar system (known as the ecliptic), as well as the tilt of Earth’s axis. During the summer, daytime is longer but nighttime is shorter, and while the Sun is high in the northern sky, the ecliptic is low in the night sky. In addition, the ecliptic crosses through the center of our galaxy in the constellation Sagittarius, which is up in the night sky the longest during the summer. Because it is difficult to discover trans-Neptunian objects within the crowded star field of our galaxy, as well as their low positions in the sky and shorter nights, there are fewer high probability events that we can pursue during the summer.

As we approach the start of the new school year, however, conditions become more favorable for RECON campaign events. Toward this end, we have already announced two upcoming events on the night of August 16-17 involving Centaur 08YB3 and the night of September 3-4 involving Centaur 13NL24. In addition, looking at the RECON Campaign Prediction Page, there are eight additional campaign opportunities before the New Year with probabilities greater than ~20% that we are currently considering as full network campaigns. The 2019-20 academic year promises to be the most productive occultation cycle of our project to date!

  • Prediction for 08YB3
  • Prediction for 13NL24

Despite being a slow occultation season, this summer has been exciting on several other fronts. We have been working on four publications related to positive TNO occultation campaigns during the last academic year. The project also continued to collect data from Apache Point Observatory, the Discovery Channel Telescope, and Canada France Hawaii Telescope to augment our occultation prediction system. And in June, we submitted a proposal to the NASA Solar System Observations Program for RECON 2.0. Informed significantly by our RECON science team meeting discussion back in March, RECON 2.0 will both upgrade and significantly enhance the efficiency and productivity of our citizen science project into the 2020s.

Upcoming Pluto Occultation

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RECON is gearing up for an important science opportunity involving Pluto.  As shown below, the shadow path of Pluto passes over most of the United States as the dwarf planet occults star GA0680:34878053 on Tuesday evening, August 14 (August 15 around 05:30UTC).

Shadow path prediction for Pluto occultation provided by RECON

We’ve posted a star field image of GA0680:34878053 on the Pluto Occultation Event Page.  Because the target star is relatively bright (mag 13.0), RECON sites will be recording this event with a sense-up of 32x.

Pluto starfield at senseup 32x

As with all RECON campaigns, we ask that team members practice taking a recording of the target star field prior to event night. This provides an opportunity to test out RECON equipment and build confidence in recognizing the star field. During the practice session, we also encourage team members to confirm that their Camera Settings are set properly.

Good luck to our RECON sites as well as all other observers planning to participate in this important occultation opportunity!

Optional IOTA Campaigns

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There are two main belt asteroid occultation opportunities for teams located from:

  • Southern Oregon to Portola CA on Friday night, July 21 around 11:20PM PDT/MST
  • Owens Valley down to Lake Havasu City AZ on Saturday night, July 22, around 11:04PM PDT/MST

Both campaigns are optional, but they provide great practice opportunities and will contribute to IOTA efforts. Participating teams are encouraged to sign up using OccultWatcher (or to contact John Keller so that he can sign your team up on OW). Details are provided below.

(1428) Mombasa:
RECON Teams: North Lake OR to Portola CA
Date: 22 Jul 2017 at 06:21 UT
Recording Window: 06:20-06:23 UT
Sense-up: 32x
IOTA Details: http://www.asteroidoccultation.com/2017_07/0722_1428_58040.htm

http://www.asteroidoccultation.com/2017_07/0722_1428_58040_Map.gif

(76) Freia:
RECON Teams: Bishop CA to Lake Havasu City AZ
Date: 23 Jul 2017 at 06:04 UT
Recording Window: 06:03-06:06 UT
Sense-up: 16x
IOTA Details: http://asteroidoccultation.com/2017_07/0723_76_58054.htm

http://asteroidoccultation.com/2017_07/0723_76_58054_Map.gif

 

RECON Campaign involving Chiron!

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Happy Fourth of July, RECON!!!

We wanted to provide a heads up about an exciting opportunity to measure Chiron, a 100-km Centaur with suspected ring structure(s)!  We will have an event page up shortly, but the map below provided by LESIA at L’Observatoire de Paris shows that the probabilities of successfully recording this object are high and that the extended RECON network down to Arizona is well positioned to map any extended structures associated with the main body!

Prediction map for occultation by Centaur Chiron on 2017 August 15 UT

The event will occur early on the morning of Tuesday, August 15 around 11:51 UT (4:51AM PDT/MST). Twilight will be approaching during the occultation, but there should be plenty of time to get onto the field prior to this. Mark your calendars now and stay tuned for details!

Not the best night for occultation astronomy!

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Our RECON event this Friday evening involving Centaur 07RG283 is going to be challenging to begin with, given that that target star (UC4-683-022040 in Perseus) is a very dim object at magnitude 16.3.  While still within reach of our telescope-camera system, clear skies will be required.

Unfortunately, as the Clear Sky Clock sky forecast map below shows, clear skies this Friday evening will be hard to come by!  In a rare reversal, sky conditions in Washington could be marginally better than the rest of the network, although even here things will be dicey.  Such are the challenges of ground-based astronomy research.  While we anticipate most sites will be clouded out, we appreciated all teams completing the RECON Campaign Observation Report Form, which will be available for one week following the event time.

Sky forecast map at event time for 07RG283 event.

 

RECON Opportunities in January 2017

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Most of the RECON network was clouded, rained, or snowed out during our last event on December 11, 2016. A handful of sites in Southern Oregon/Northern California and Southern California/Arizona were able to record the star field and are uploading their video data for analysis, but the campaign was definitely limited by poor sky conditions for this final campaign of the 2016 calendar year.

Given the challenges that the network has had with clouds and such, we wanted to announce two promising optional campaigns in early January, which are also great practice opportunities to prepare for our next official campaign later next month.

Next Full Campaign on 23 January around 05:51 UT

Looking forward to 2017, our next full network campaign will be Monday evening, January 23 around 9:51PM PST / 10:51PM MST. With a 1-sigma uncertainty of just over 1,100 km, this campaign involving Centaur (471512) 12CG is our highest probability TNO opportunity for the month of January at 36%. We will be creating an event page shortly, and the sign-up form for this official campaign will go live on December 23.

Large Classical KBO on 2 January around 07:59 UT (OPTIONAL)

Prediction for Classical KBO Sila-Nunam on 2017 January 2 UT

Prediction for Classical KBO Sila-Nunam on 2017 January 2 UT

Estimated as somewhere between 220-550 km in diameter, the shadow path of large Classical KBO (79360) Sila-Nunam is predicted to pass over the RECON network, with a 1-sigma uncertainty of just over 2,000 km. If the shadow does pass over RECON, we will definitely detect it even if not all telescope sites are able to observe the event occurring roughly 24 hours into the New Year. We strongly encourage any and all teams that are up for this event to give it a go, especially if weather forecasts look good. However, we didn’t want to push the network too hard after our Thanksgiving campaign event, so this will be an optional event. You will be able to sign up for this optional RECON event starting next week.

Regional Multi-Chord Observation on 7 January around 06:45 UT (OPTIONAL)

Prediction for Main Belt Asteroid (362) Havnia on 2017 January 7 UT

Prediction for Main Belt Asteroid (362) Havnia on 2017 January 7 UT

Equally exciting is a unique multi-chord opportunity involving Main Belt Asteroid (362) Havnia on Friday evening, January 6, around 10:45PM PST / 11:45PM MST. As shown on the IOTA prediction map to the left, the slow-moving shadow will travel from south to north. Depending upon how far west or east the shadow lands, all RECON sites in Arizona, California, Nevada, and possibly Oregon can help contribute to this multi-chord observation opportunity. Because the event will not involve telescope sites in Washington, we are announcing this as an optional regional campaign. Many IOTA members are planning to observe, and you are strongly encouraged to contribute this research effort and gain more practice time. You can sign up for this event using OccultWatcher, and a RECON sign-up form will also be available next week.