Not the best night for occultation astronomy!

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.

 

What’s in a name?

Our next RECON event this coming Monday evening involves Centaur 12CG!  A challenging component of this event is that the target will be rising low in the eastern sky. Note that this won’t give our teams a ton of time to lock on the star field.

We wanted to take this opportunity to talk for a second about the naming convention for TNOs and other minor planets.  For all of our previous events, you may have noticed that objects had names like 14UT114 and 08FC76, while our event this week does not have a number at the end. Let’s break this down.

The name 12CG indicates that this object was the seventh minor planet discovered in the two week period between February 1 – February 15, 2012.  The first two digits (12) represent the year of discovery and the first letter (C) indicates the half-month of discovery. The letter A is for objects discovered between January 1-15, B is for January 16-31, and C for February 1-15. Note that the letter “I” is skipped, resulting in Y representing the 24th half-month of December 16-31. The second character (G) is the order of discover, with A being the first object in that period and G being the seventh. Here again, the letter “I” is not used, so this naming convention can be used for the first 25 objects discovered in a given half-month.

So why do most TNOs end with a number while 12CG does not? After the 25 object discovered in a half month,a number is indexed at the end of the name and second alpha character cycles back through the alphabet. Thus, while the 25th discovered object between February 1 – February 15 would be 12CZ, the 26th object would be named 12CA1, and the 27th would be 12CB1.

Ready to quiz yourself? Try 14UT114:

  • 14U = Object was discovered between October 16-31, 2014
  • T114 = We’ve cycled 114 times through the 25 letters of the alphabet (minus the letter “I”), or 114 x 25 = 2,850 times. The letter T indicates it is the 19th object after these 2,850 prior objects. So the object is the 2,869th discovery of this half-month.

How about 08FC76? . . . yup, the 1,903rd minor discovered between March 16-31, 2008. For more information and clarification, check out the following Wikipage on provisional designation in astronomy.

Good luck to all of our teams this Monday evening!!!

Happy Winter Solstice, 2016!

On this Winter Solstice, the RECON Team wanted to wish all a happy holiday season!!!

RECON Team Meeting in Carson City, August 2016

RECON Team Meeting in Carson City, August 2016

We are extremely grateful to all of our RECON students, teachers, amateur astronomers and community members who have contributed to this year’s activities.  Below is a quick RECON Year in Review!

All together, we attempted 8 full network campaigns, set up essential data infrastructure for RECON campaigns, and published 2 manuscripts in The Astronomical Journal. With most video files now uploaded into the RECON database, we are currently busy analyzing video from the above events as we prepare for our upcoming January 2017 campaigns.

In addition to our team meeting in Nevada, John had the pleasure of visiting sites in Oregon, Northern California, Owens Valley, and along the Colorado River while Marc visited sites in both Washington and Arizona. We also has a new team join from Wildwood School in Los Angeles. Throughout all of our interactions, we continue to be impressed by the dedication and enthusiasm of our RECON communities!

Wishing you the warmest of holidays!!!

John, Marc, Ilianna, Diana, Matthew, Audrey, and Jeralyn

 

RECON Opportunities in January 2017

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.

Cloud Forecast for 14UT114

Cloud cover will likely pose challenges for many of our telescope sites during tonight’s event on Sunday morning, December 11 around 08:55 UT. Teams south of Reno and along the Colorado River and around have the best shot at recording this event. To see sky predictions for individual RECON sites, you can visit our Sky Conditions Page.

National Weather Service cloud cover forecast for Saturday night/Sunday morning.

National Weather Service cloud cover forecast for Saturday night/Sunday morning.

Despite weather conditions, our telescope teams will keep an eye on their local skies and do their best tonight. Following the campaign event, we ask all teams to complete a RECON Campaign Observation Report Form.  This link will be active for one week following the event.

Final 2016 RECON Event

We wanted to provide a quick update on how things went last week during our Thanksgiving RECON campaign and also provide a heads up on our final event of 2016.

November 23 Event Involving 08FC76

With the exception of Tulelake, California, weather got in the way of observing for all telescope sites from Oroville, Washington down to Carson City, Nevada. Unfortunately, clouds did not part in Central Oregon until after the event. However, clear skies prevailed for our 20 sites from Yerington, Nevada south to Yuma, Arizona. Based upon reports, 15 of these sites successfully acquired the target field and recorded the event, while 5 sites encountered technical issues, primarily involving power and alignment issues. For the next few days, you can view reports from all RECON teams on our Event Reporting Status Page.

Teams that acquired data are currently uploading video data to Southwest Research Institute in Boulder for further analysis this month.

December 11 Involving 14UT114

Our final campaign of 2016 will be Saturday night/Sunday morning, December 10-11. The centerline prediction for Centaur 14UT114 passes over Maupin, Oregon.

Prediction for 14UT114 on 11 December, 2016 UT

Prediction for 14UT114 on 11 December, 2016 UT

With a 1,200-km uncertainty, over 50 RECON telescope sites from Oroville, Washington to Blythe, California are in the 1-sigma shadow zone. All teams are crossing their fingers for clear weather for this occultation opportunity, which currently has a 37% probability of detection by the network. All RECON teams are asked to submit the RECON Campaign Signup Form by this weekend. Submitted reports can be viewed on our Signup Status Page.

 

Over 50 RECON teams are prepared to pursue an exciting observation campaign tonight, which occurs on Wednesday morning just before 4AM PST / 5AM MST.  The forecast map shown below predicts great sky conditions for all RECON teams south of Portola, California, and a promising belt of partly clear conditions throughout Central Oregon from Tulelake up to The Dalles.

Sky forecast map at event time on 23 November at 12:00UT (http://www.cleardarksky.com/)

Sky forecast map at event time on 23 November at 12:00UT (http://www.cleardarksky.com/)

To see sky predictions for individual RECON sites, you can visit our Sky Conditions Page.

Good luck to all of our teams as they do their best to record the star field for this high probability campaign event!  The 1-sigma uncertainty for the shadow prediction indicates that telescopes sites from Madras, Oregon all the way to Idyllwild, California all have have high odds of recording Centaur 08FC76 as it occults our target star.

Rain, snow, or clear skies . . . we ask all RECON teams to complete a RECON Campaign Observation Report Form.  This link will be active for one week following the event.

Reading RECON Event Detail Page

As RECON prepares for our our upcoming campaign early Wednesday morning this week, we thought we would take this opportunity to point out some of the interesting information found on the Event Detail Page for each RECON event.

For our upcoming event, teams should print out both of the following important webpages:

Event Overview:

The Event Detail Page for every campaign starts with useful information characterizing the event.

Event_Detail_Page_Intro

This introductory section provides lots of cool details:

  • An object named (281371) 08FC76 is going to occult a star named UC4-565-008609.
  • The predicted shadow reaches the point closest to Earth’s center at 11:55:36 Universal Time on November 23, 2016.
  • We provide J2000 coordinates (the RA and DEC of the target star back in 2000) and equinox of date coordinates (the RA and DEC for the star today). Note that the coordinates are close but not exactly the same because Earth is slow precessing (or wobbling) on its axis. Our CPC-1100 telescopes use equinox of date coordinates.
  • The target star is faint — magnitude of 14.6 using a Red (R) filter — but about 100x brighter than the TNO — magnitude 19.3 using a Visible (V) filter). Every 5 orders of magnitude is 100 times fainter. RECON setups can measure down to about magnitude 16, which means our sites will be able to record the star but will record no signal when the fainter TNO is passes in front of it —fingers crossed!
  • The waning crescent Moon should not be an issue for this campaign.  It is only 29% illuminated and reasonably far away (115 degrees) from the target.
  • For our upcoming event, the centerline passes directly over the RECON network. Click the link on the page for a detailed RECON map of the network.
  • To the right of the globe are details about the position, motion, size, and dynamical classification of the TNO. In this case, we are dealing with a Centaur which, at 10.6 AU, is currently just outside the orbit of Saturn. Note that we don’t know the actual albedo, or reflectivity, of the Centaur — that’s another thing we will be able to determine if we measure the object’s size.
  • The 1-sigma uncertainty in time for the event is 47 seconds and the cross-track uncertainty is 595 km. This means that there is a 68% chance that the prediction times listed are good to within 47 seconds, and a 68% chance that the shadow will land within 595 km of the centerline shown. This is why we need so many telescopes and need to record video lasting longer than a few minutes.

Star Training Set:

Event_Detail_Page_StartrainingNext, we provide teams with a star training set. This is a list of 5-6 stars, in addition to the target star, that can be used to provide an indication of how accurately the telescope is aligned and in what direction. You’ll notice that the magnitudes of the stars listed are going from brightest (mag 0.8) to dimmest (mag 14.6), and that the separation between the star and the target is getting smaller (from 11.52 degrees down to 0.24 degrees). By pointing the telescope at each object, the team can get a sense of where the target is likely to appear in the camera field of view when they use the final coordinates for TNO (281371) 08FC76.

Star Chart:

Following this, an automatically generated star chart shows nearby stars along with a green rectangle representing the RECON camera field of view. Note that we are still tweaking how this star chart displays, and for now the star chart provided on the Event Page is a better depiction of the star field at the actual time of the event.

Site Table:

Finally, we provide a table listing all of our RECON sites along with useful information unique to each location. Among other information, the text just above the table provides an indication of the median spacing of the RECON network for this event (26.8 km) and the probability of success assuming clear skies (67.1%). These REALLY good odds for TNO occultation astronomy are only made possible by our awesome network of team members spanning a baseline of roughly 1,700 km. The probability takes into account the uncertainty in the position of the TNO and the target star, the estimated size of the object, and the median spacing of telescopes across the network.

Event_Detail_Page_Table_Start

For each RECON site, you can read off the following information:

  • For all of our sites the Sun is down (negative altitude), the sky is dark, and the Moon is up.
  • The position of the star (star altitude and azimuth) is provided for each site. 10 degrees corresponds to a fist held at arms length. Due north is 0 degrees azimuth, 90 degrees is east, 180 degrees is south, and 270 degrees is west. For Oroville during the event time, the star will be 34.8 degrees above the horizon (about three and a half fists) and in the direction of 265 degrees, or just 5 degrees south of due west.
  • Remember the 1-sigma cross track error of 595 km above?  For each site the table lists how far the site is from the centerline prediction. Note that all RECON sites south of Madras/Culver (X-track = 569 km) are within the 1-sigma zone.

All times on the page are in Universal Time (UT) and need to be converted to local time. Our teams on Pacific Standard Time (PST) are 8 hours behind UT, and our teams on Mountain Standard Time (MST) are 7 hours behind UT. Let’s take a look at three examples:

  • The recording window for Oroville is 11:47:21-11:56:15 UT (see above). Because they are on Pacific Time, our Oroville team will subtract 8 hours and record from 03:47:21-03:56:15 PST.
  • The recording window for Yuma Arizona is 11:46:54-11:55:48 UT (see below). Because Yuma (and all of Arizona) are on Mountain Time, our team there will subtract 7 hours and record from 04:46:54-04:55:48 MST.
  • Our team in Laughlin/Bullhead City, with a start time of 11:46:56 UT, is in the funkiest situation (see below).  If the team observes from Laughlin, Nevada, they will start recording at 03:46:56 PST; if they are in Bullhead City, Arizona, they will start recording at 04:46:56 MST.  Both are the same Universal Time which is why astronomers prefer to use UT rather than local time!

Event_Detail_Page_Table_End

J2000 Star Training Set (NOT for standard RECON Setups):

The final table provided on the Event Detail page is the same star training set using J2000 coordinates. Some of our volunteer sties are using scopes that use J2000 coordinates, unlike our RECON Celestron scopes. Standard RECON sites should use the star training table at the top of the page above the star chart!

RECON Prediction System at Work

As with all science, RECON is a work in progress, and we will continue to refine our predication and observation planning tools. All of the above useful information is available for each occultation prediction found on the Global TNO Event Candidate List and RECON TNO Event Watchlist. Each of these lists is updated weekly and provides predictions looking two years into the future – including our next RECON event after this week involving Centaur 14UT114 on 11 December, 2016 UT.