Comet C/2013 A1 (Siding Spring) at Mars
Comet C/2013 A1 Siding Spring (arrow) approaching Mars (top of frame) on 2014 October 19 at 17h25m30s UT, in a photo by Tim Cooper of Bredell, South Africa. This image was taken using a 30cm LX90, SXV-M7 camera, a ten second exposure unfiltered. Field of view is about 7' wide.
2014, October 19 - Comet C/2013 A1 (Siding Spring) just passed by Mars. We are now waiting to hear from orbiters and landers at Mars if any meteors were detected, potentially providing unique information about the physical properties of large cometary dust grains ejected very freshly from a comet nucleus. It will take some time to bring the data to Earth and do the analysis. Results from the observations will be discussed during a special session Comet C/2013 A1 (Siding Spring) at Mars at the 2014 AGU Fall Meeting in San Francisco on December 18.
Comet 209P/LINEAR at Earth
METEOR SHOWER FLUXTIMATOR
In late May 2014, comet 209P/Linear will make the 9th closest approach to Earth of comets on record. In the night of Friday May 23, when Earth is at the node of the comet orbit, some of the debris ejected by the comet during returns to the Sun in the late 18th, 19th and early 20th centuries is calculated to be in Earth's path. If the comet was active in those years, and that is a big if, a new meteor shower may be visible from the United States and southern parts of Canada. Slow moving meteors would radiate from the vicinity of the north star. Keep your expectations low, but don't miss it!
- Peter Jenniskens and Esko Lyytinen
Calculate at what local time the shower is visible at your location. Count is the estimated number of meteors per hour of clear sky naked eye observing for a given prediction model.
[JAVA needs to be enabled]
Note: Apparent activity is calculated based on assumed peak rate of 60/h at 7:20 UT, 3.5h total duration. Change shower setting to see other prediction models.
Several websites will post near-real time updates on the meteor shower. Check out the following links:
+ CAMS Sunnyvale Station live video feed - via Ustream (Jim Albers)
+ CAMS Brentwood Station - via Adobe Connect (Dave Samuels)
[SLOOH comet 209P/LINEAR special]; [Spaceweather.com]; [Virtual Telescope Project]; [International Meteor Organization]
Frame-by-frame development of a Camelopardalid on 2014 May 24 at 01h58m08s UT. The first 27 frames are shown as a sequence of one every other to separate the meteor images. After peak brightnes, the full sequence shows the debris-wake fromation and the slowing down of the remaining material towards the end by the strong curvature in the position of the end points. Original recording by Peter C. Slansky; compilation by Jim Albers and Peter Jenniskens.
July 22, 2014 - Naked eye observers were disappointed by the poor showing of the May 24 Camelopardalids meteor shower from the close passage of comet 209P/LINEAR to Earth last month, but the weak activity of this never-before-seen shower now has scientists excited. An analysis of airborne and ground-based observations by Peter Jenniskens, published in the latest issue of the Journal of the International Meteor Organization, finds that this comet's meteoroids were unusually fragile and the shower was dominated by meteors too small to see with the naked eye. The dust encountered by Earth in May was more than a century old. One explanation for the lack of large meteoroids is that they did not survive the harsh conditions of space. [Manuscript]; [Press Release]
The nucleus of comet 209P/Linear as imaged by the Arecibo radar on May 27. [More]
May 29, 2014 - In observations led by Ellen Howel, Patrick Taylor, Allessondra Springmann, Linda Rodriguez Ford and Luisa Zambrano Marin, NASA, USRA and Arecibo Observatory released a series of images of the nucleus of comet 209P/Linear taken on May 27. The comet was measured to be about 2.4 by 3 km in size (1.5 x 1.8 miles) and elongated in shape. This is only the fifth comet nucleus imaged from Arecibo and the most detailed. The nucleus shows several features, possibly ridges or cliffs. Howell reports that the 11 hour period proposed earlier from optical observations by Carl Hergenrother matches the Arecibo observations. The data do not seem to have the large grain (> 2cm sized) coma that was seen on other comets.
May 29, 2014 - Alessondra Springmann is reporting that Arecibo Observatory is back in operation after inspections following the 5.8 earthquake yesterday. The comet, however, is now gone from the Arecibo accessible declination range.
May 29, 2014 - Kenneth Obenberger and colleagues of the University of New Mexico report the first well documented detection of natural radio emissions of meteors in the 25-75 MHz range in bright fireballs. This frequency range is higher than the tentative ELF signals reported in the past (linked to electrophonic sounds of fireballs), but lower than the 1-11 GHz frequency range targeted during the search for natural radio emissions by the SETI Institute's ATA telescope May 24.
209P/Linear on evening of May 27 in real-time video test by Rick Baldridge (Peninsula Astronomical Society) from Foothill College Observatory.
May 28, 2014 - Tonight, the SSERVI at NASA Ames Research Center will provide near real-time video of the comet passing by Earth, streaming from Foothill College Observatory, between 9:30 pm and 11:30 pm PDT (00:30 to 2:30 am EST).
May 28, 2014 - Arecibo observations have been cancelled until the telesope has been checked, following a 5.8 magnitude Earthquake in Puerto Rico at 17:15:04 pm local time on May 28, according to a tweet by Robert Minchin. Based on data taken so far, Alessondra Springmann tweeted: "These new radar images of comet 209P/Linear show really cool structure at 0.1 microsecond resolution." Images will be released in June.
May 27, 2014 Lance Benner of NASA/JPL is reporting that the Goldstone radar has obtained coarse-resolution imaging, which shows the nucleus elongated but barely resolved. The observed rotation appears to be consisted with the earlier 22-h rotation period derived from photometry.
May 26, 2014 - Faint, weakly active, comet 209P/Linear is still approaching Earth. Closest distance (at 0.0554 AU or 22 lunar distances) will be at 07:51 UT on May 29. That means that best viewing for US observers will be in the evening of Wednesday May 28. In a good size telescope, watch the comet move past the background of stars. [ Finder chart from Heavens Above]
May 26, 2014 Astronomy Picture of the Day featured this Memorial Day weekend impression, a composite of Camelopardalids and the International Space Station, by Malcolm Park of the North York Astronomical Association.
May 26, 2014 - Summary of first reports of shower observations by Kelly Beatty of Sky & Telescope.
Radio forward meteor scatter counts in 10-minute intervals.
May 26, 2014 - Radio forward meteor scatter results by Jeff Brower (Brittish Columbia) confirm the activity profile from Japanese observations. Ilkka Yrjola (Finland) is more sensitive to brighter Camelopardalids and finds these scattered in the period 1-12 UT.
Compilation of Japanese radio forward scatter rates collected by Hirofumi Sugimoto.
May 26, 2014 - Hirofumi Sugimoto has collected Japanese radio observations and constructed this activity profile. Most reflections pertain to underdense echoes (faint meteors).
Left: CMOR radar detections of +6 to +7 magnitude meteors during a 24h period before 20h UT May 24. Right: Results are compared to the CAMS video data of +0 to +4 magnitude meteors between 4 and 12h UT, May 24.
May 26, 2014 - A component of faint meteors was seen by radar and forward meteor scatter systems. Unexpected from the low magnitude distribution index of meteors seen visually, Peter Brown of the University of Western Ontario reports that the Canadian Meteor Orbit Radar (CMOR) detected 92 Camelopardalids between 0 and 11 UT on May 24, with highest rates between 7h30m and 8h00m UT. The shower radar echoes were confined to faint meteors, equivalent to visual magnitudes +6 to +7, from small milligram and sub-milligram mass particles. This may represent a different dust component to the brighter meteors detected fromt he aircraft and by CAMS.
May 26, 2014 - Camelopardalid with a strong wake at 07:48:13 UT, May 24, captured near the horizon in the constellation Corvus in one of the intensified cameras during the airborne observing campaign.
May 26, 2014 - Updated: Approach direction of the new shower meteors in CAMS data. So far, 20 trajectories have been calculated, of which 5 are from single-CAMS stations in California and the Netherlands. The graph shows the geocentric radiant position of each meteor radiant, with a circle showing the predicted Camelopardalid radiant position. The radiant is compact, most (or all) of the outlayers are either the result of measurement error, or were detected outside the core of the profile. The first trajectory was captured on May 23 at 4:48 UT, the last on May 24 at 22:27 UT. The temporal distribution is broad, with most detected between 4:41 and 9:37 UT (with some clouds interfering around the peak at 6-8 UT).
May 24, 2014 - Early activity: the single-CAMS network in the Netherlands (Carl Johannink) is reporting that they detected three early Camelopardalids at 21:34 UT (stations Henglo - Gronau), 23:56 UT (stations Alphen a/d Rijn - Hengelo), and 23:58 UT (stations Utrecht - Alphen) on May 23. Apparent radiants from the two most precisely measured Camelopardalids were at: RA= 142.9+/-2.8, Dec=82.4+/-0.4 and speed Vinf = 16.9 km/s, and RA=139.7+/-0.9, Dec=81.9+/-0.3 and speed Vinf = 18.8 km/s, respectively.
Trajectory and lightcurve of a Camelopardalid filmed from the single-CAMS stations 214-Foresthill (Jim Wray), 216-Brentwood (Dave Samuels), and 218-Walnut Creek (James Head) at 06:41:14 UT May 24.
May 24, 2014 - A trajectory and orbit in space were calculated for a Camelopardalid that was filmed at three single-CAMS stations in the San Francisco Bay Area at 06:41:14 UT. The meteor appeared to arrive from a direction Right Ascension = 151.3 +/- 1.0 deg., Declination = 78.6 +/- 0.6 deg., with speed 19.4 +/- 1.0 km/s, close to predictions. Last night's CAMS data from the main network in California are now being processed.
One minute count of Camelopardalids by observers visually monitoring three of the intensified cameras.
May 24, 2014 - A more complete picture will follow once the tapes are studied carefully. For now, three visual observers monitored three of the intensified cameras in real time between 06:08 and 08:23 UT. Their 1-minute counts of Camelopardalids are shown in the graph above. As a first impression, the sightings correspond well with the predicted trail encounter times (using calculations by Jeremie Vaubaillon). Trails from the late 19th century (1873-1903), however, did not seem to contribute. We saw our brightest Camelopardalids at the end of the flight, when the most recent trails were encountered that were predicted to be in Earth's path.
May 24, 2014 - An example of one of images taken by the spectral camera is shown above, showing the planet Mars and its first order spectrum on each side. Mars will travel through the coma of comet C/2013 A1 (Siding-Spring) on October 19 this year.
Back from a successful mission. From left to right: Jim, Mike, Alan, Ron and pilot Connor.
May 24, 2014 - Did you see it? There was a new shower in the sky last night and we had a prime view of it. Wheels up was right on schedule. We followed a northern flight path along the California coast, staying clear of clouds throughout the mission. All cameras were working as expected. About 12 hours of video was collected by five intensified cameras monitoring the horizon left and right of the aircraft, and at total of 72,764 spatial and 5,200 spectral images were taken with two Luminera 2-1R Silicon based cameras.
SETI Institute research team ready for the shower. From left to right: Ron Dantowitz, Peter Jenniskens, Mike Koop and Jim Albers.
May 23, 2014 - The SETI Institute observing team is preparing to take to the skies this evening. Departure is scheduled for 10:30 pm PDT.
Cloud forecast for 6h UT May 24, with yellow arrows showing the currently planned meteor shower mission flight route.
May 23, 2014 - Tonight's flight plan for the Beechcraft King Air 90 aircraft is to take us over the Pacific Ocean and northern California in a region with no cloud. Goal is to be above the lower atmospheric dust and have a clear view of the horizon.
May 23, 2014 - The research team for SETI Institute's airborne observing campaign is assembling. Airborne team member Ron Dantowitz, director of the Clay Center Observatory at Dexter Southfield School (left in picture), just arrived from Boston at San Jose Airport and was greeted by Peter Jenniskens.
May 23, 2014 - Peter Jenniskens talks about the upcoming shower in this SLOOH webcast.
May 23, 2014 - SETI Institute's (very own radio telescope will temporarily halt its search for extraterrestrial intelligence tonight and tomorrow evening (May 23, 24) and begin a new search for radio wave emissions from meteors and their trails. When meteors pass through Earth's atmosphere, they generate trails of glowing ionized gas (plasma) that causes the appearance of "shooting stars." This glowing, or emission, is expected to extend down to radio frequencies, but we don't know how strong the emissions are. No one has yet observed radio emissions from meteors or their plasma trails. Using the high sensitivity and especially large field of view of ATA's "radio camera," we hope to discover radio emission if/when a meteor enters our field of view. If successful, we will have demonstrated a new way to examine meteors, revealing the nature and even chemical structure of ionized gas left in the meteor wake. Radio observations may also permit estimates of the effective temperature and dissipation mechanisms of the plasma. With luck, we may open an entirely new window on meteor phenomena.
May 23, 2014 - First one spotted? The anticipated shower is still 30 hours away, but this morning the CAMS network in the Netherlands and Belgium, administered by Carl Johannink, reports that the very end of the night cleared for a short period of time, resulting in two measured meteor trajectories. The second, at 01:20:46 UT May 23 came from a direction right ascension RA = 227.6 +/- 0.4 deg. and declination 80.9 +/- 0.2 deg., and entered with a speed of 20.9 +/- 0.3 km/s. The orbital elements for this meteoroid were calculated as: perihelion distance q = 0.995 +/- 0.003 AU, a = 3.03 AU (1/a = 0.33 +/- 0.03), i = 25.9 +/- 0.6 deg., w = 163.2 +/- 1.3 deg., and node = 61.6690 +/- 0.0004 deg. Compare this to 209P/Linear's 2014 orbit: q = 0.969 AU, a = 2.96 AU, i = 21.2 deg., w = 152.4 deg., node = 62.8 deg. This is an unusual direction for sporadic meteors to come from. On the other hand, this meteoroid could still represent dust from the weak background activity spotted earlier due to older dust ejecta of 209P/Linear.
May 23, 2014 - The Arecibo radar team has spotted comet 209P/Linear by radar. "Looks like a narrow 2-kilometer bowling pin or peanut," twitters Robert Minchin.
May 22, 2014 - Sunnyvale has clear weather tonight. Check out the CAMS Sunnyvale Station live video feed test-run from Jim Albers and Peter Jenniskens.
May 22, 2014 - Check out this video of 209P/Linear meteors, from observations by the CAMS meteor surveillance project of the SETI Institute and NASA Ames in the San Francisco Bay Area. The meteors are from a weak annual shower active on June 6-14 and appear to represent older debris from comet 209P/Linear. They give a good impression of how the new shower's meteors may look like.
May 22, 2014 - The SETI Institute will send Jenniskens and his observing team to the skies above 20,000 feet to observe the event above the clouds and atmospheric dust. Jenniskens will also study the shower with his autonomous meteor shower surveillance stations at Lick Observatory, Fremont Peak Observatory and in Sunnyvale. The flight will originate from Palo Alto, Calif. at 10:00 PM PDT, head towards Seattle, and return to Palo Alto approximately four hours later. Their mission patch is shown above. [More here]; [Previous missions]
May 22, 2014 - Lance Benner of NASA/JPL is reporting that the first radar echoes from the nucleus of comet 209P/Linear were detected last night at Goldstone. Marina Brozovic led the observations. So far, continuous-wave (that is, Doppler-only) echoes were obtained, and coarse-resolution ranging measurements. There are no detailed images yet, but they are hopeful such images will be obtained next week when the comet is closer and the radar signal-to-noise ratio is higher. So far, there have only been echoes from the nucleus itself, not yet from the comet coma.
May 22, 2014 - David Asher and Robert McNaught just posted their predictions of the meteor shower here. The 22-revolution trail released in 1903 and the 47-revolution trail released in 1778 are smack in Earth's path, peaking at 7:09 UT and 7:47 UT, respectively. A lot of other trails have very short miss distances, less than 0.001 AU.
Comet 209P/Linear on May 18.69 UT, stars removed. Photo by Q. Ye, with permission.
May 22, 2014 - Meteor astronomer Quanzhi Ye of the University of Western Ontario obtained the image above with colleages Xing Gao and Man-To Hui at Xingming Observatory on May 18.69. They carefully removed all background stars to bring out the faint tail of the comet. The tail is now at least 15 arc minutes long and very impressive. Also read more about Ye's expectations.
May 22, 2014 - Jeremie Vaubaillon of I.M.C.C.E. in Paris, France, reports that Moon impacts are likely to happen between 01:30 and 05:30 UT on May 24. He calculated trail encounters with the Moon from dust ejected between 1703 and 1919. This puts observers in western Europe and eastern south America in a good position to see these.
May 21, 2014 - If we do get a shower this year it will be a one-off because the comet itself is so nearby. In the near future, however, we may still glimpse the shower on occasion. The comet orbit will continue to evolve, but passes close to Earth's orbit in each 5-year return from 2014 to 2044. Esko Lyytinen and Peter Jenniskens report that the recent 2009-ejected dust trail will be in the Earth's path on 2019 May 24 at around 11h UT, during the next return of the comet. That time, however, the comet itself will not be close to Earth. It is near the comet position that dust density tends to be highest in these trails.
May 21, 2014 - The brightness of comet 209P/Linear is slightly lagging the predictions, but only by about a magnitude, now expected to peak at about +12 magnitude on May 29. [Comet lightcurve]
May 20, 2014 - Dave Schleicher of Lowell Observatory reports on observations of the optical emissions from the volatile ices sublimating from comet 209P/Linear (creating radicals OH, CN, and C2), confirming that the comet has extremely low activity for its size. The water production rate impies an effective area of water sublimation of only about 0.01 square kilometer. If that was all from one location on the comet nucleus surface, it would be an area of only 100 x 100 meters. More in an upcoming CBET.
Stars are plotted for 2 a.m. local daylight time as seen from mid-northern latitudes. Image (with permission): Sky & Telescope.
May 20, 2014 - Meteors from the shower can appear anywhere in the sky, but they will appear to originate from a point, called the radiant, in the constellation of Camelopardalis, the Giraffe, not too far from the north star. [Story]
A meteor from comet 209P/Linear, in an image compiled from video taken by Peter Jenniskens with the CAMS video camera network at 7:59:46 UT on June 13, 2012. The meteor moved from top to bottom through the constellation of Serpens Cauda.
May 20, 2014 - In a paper submitted to Icarus, Peter Jenniskens and co-authors report on the detection of a weak stream of meteoroids that move in an orbit similar to that of 209P/Linear, but are seen annually in the period June 6-14. They, too, may represent older dust ejecta from the comet. Assigned the name "sigma Ursae Majorids", with number 677 and code "SIM" in the IAU Meteor Shower Working List, this is one of several new showers detected by CAMS.
Position of possible lunar impacts around 4:10 UT, May 24.
May 20, 2014 - Observers in south America (and perhaps in Western Europe and western Africa) may not be able to see the meteor shower, but they could watch for impacts of meteoroids on the Moon. Peter Zimnikoval from Banska Bystrica, Slovakia, reports that there will be relatively good conditions to see lunar impacts of meteoroids from comet 209P/LINEAR. With the moon at an elongation of 54.8 degrees west. According to Zimnikoval, the moon will reach the filament about 2.86 hours before the Earth. In that case, the best time for observing moon impacts will be in the 2 hours around 4:10 UT, May 24. Above are the graphs prepared by Zimnikoval. Asked to verify the calculations, Peter Gural finds a similar distribution of possible impact positions, but a peak at about the same time as the anticipated meteor shower around 7h UT, because of the Moon-Earth line being about perpendicular to the direction of the approaching meteoroids in heliocentric orbits. That would mean that observers in south America and the eastern United States are best positioned to observe the impacts.
Contrast enhanced image of 209P/Linear on May 19, as photographed by Alfons Diepvens of Balen, Belgium.
May 19, 2014 - Comet 209P/Linear now sports a faint but growing ion tail.
Direction from which meteors approached us in 2011-2013, as measured by CAMS.
May 18, 2014 - The graph above shows the direction from which meteors approach us in normal years. The circle is the direction of the possible new shower.
May 17, 2014 - Alan Hale, from Hale-Bopp fame, reports seeing the comet visually: "I did not have the best sky conditions tonight (thin cirrus clouds moving through), but I did - finally! - pick up this comet. I followed it for about 45 minutes, and motion was obvious within just a few minutes. May 18.17 UT, m1 = 14.1, 0.3' coma. The comet did appear slightly non-stellar." Hale used a 41 cm reflector at 229 times magnification.
209P/Linear on 17 May, in five 180-s exposures remotely taken by Gianluca Masi of Ceccano, Italy, using a telescope that is part of the Virtual Telescope Project. The comet was only at 30 degree elevation and the sky illumiated by a bright 86 percent moon.
May 17, 2014 - Comet 209P/Linear is approaching Earth, now at a faint magntiude +12, but well in reach of many amateur telescopes. The tail has grown to about 6 arc minutes. It's current position is on one edge of the famous star counting field number 3 in the constellation the Big Dipper (Ursa Major), used to determine how bright your sky is for meteor observations. Note: when you plan do make meteor counts on May 23, take care to do these counts in periods of 1 or 5 minutes, so the activity profile is well resolved.
[ Comet Finding Charts from Heavens Above]
Rain forecast for Friday night May 23, from weather.com
May 17, 2014 - Check your weather forecast. California will have partial cloud cover this week, but the forecast for May 23rd (in Mountain View, CA) is "mostly sunny", while Saturday May 24 says "sunny", raising hopes that CAMS will be able to observe the sky that night. Some rain showers are forecast in the north west and mid western states. London, Ontario, is forecast to have partly cloudy skies, with 10 percent chance of rain. Grassland National Park in Saskeatchewan, has partial clouds in the forecast. Still too early to tell?
May 16, 2014 - Comet 209P/Linear may be bigger in size than we suspected. The Central Bureau for Astronomical Telegrams just issued back-to-back CBET telegrams with a summary of the meteor shower prediction (CBET 3869) and a new set of observations of 209P/Linear (CBET 3870). In the latter, Carl Hergenrother of LPL, University of Arizona, presents results from broadband photometry of the nucleus of comet 209P/Linear in February and March. He finds a best fit synodic rotation period of 21.86 +/- 0.04 h. He also finds a diameter between 1.9 and 4.9 km, which is larger than the 0.8-1 km estimates made earlier. The comet started emitting dust at about 1.4 AU from the Sun. This is shaping up to be a normal sized Jupiter Family type comet, albeit currently with relatively low activity.
May 13, 2014 - Comet 209P/Linear on May 13 as photographed by Efrain Morales Rivera from Puerto Rico (Sociedad de Astronomia del Caribe - SAC).
May 12, 2014 - More evidence of weak past activity of 209P/Linear. In a paper in the May issue of JIMO, the Journal of the International Meteor Organization, Damir Segon, Peter Gural, Zeljko Andreic, Ivica Skokic, Korado Korlevic, Denis Vida, and Filip Novoselnik report on the detection of a weak annual shower active from April 24 to June 4 in SonotaCo and Croatian Meteor Network video observations, which appears to originate from 209P/Linear. Upon further inspection, it appears to be the same Camelopardalids shower (number 451, CAM) detected earlier by Rudawska and Jenniskens (see August 26-30, 2013, blog entry). Using a less strict association criterion, the weak activity now extends into the May 23 time frame.
May 7, 2014 - Comet 209P/Linear on May 7. Image by Alfons Diepvens, Belgium. [Other images]
May 6, 2014 - Story from Science at NASA. [More here] [Science Cast]
May 6, 2014 - Astronomer Apostolos Christou of Armagh Observatory, U.K., will travel to London, Ontario, Canda, to team up with Peter Brown and Margaret Campbell-Brown for low-light-level video observations. Brown and Campbell will observe with the CMOR radar and with optical cameras at the University of Western Ontario.
May 6, 2014 - Comet 209P/Linear passed its nearest point to the Sun today, at a distance of 0.9695 astronomical units. The comet is still 0.23 AU from Earth.
209P/Linear on May 5, in an image by Roland Fichtl of Germany.
May 5, 2014 - Peter Jenniskens will observe the shower with the CAMS meteoroid orbit and meteor spectroscopy surveillance network in the San Francisco Bay Area, California.
May 5, 2014 - Astronomor Juraj Toth of Slovakia reports that he will observe the shower with colleague Pavol Zigo from the Grassland National Park in Saskeatchewan, Canada, performing double station and spectral observations of the meteors, weather permitting.
May 3, 2014 - The month of May in a NASA video for stargazers.
May 1, 2014 - The comet now has brightened to +16.2 magnitude. [lightcurve (Alfons Diepvens)] [lightcurve (Seiichi Yoshida)]
April 30, 2014 - Mike Nolan of Arecibo Observatory reports that observations of the parent comet at this radar facility are scheduled to run from May 23 to May 28, when comet 209P/Linear is in declination range. The radar is expected to resolve the 800-1km sized nucleus and also see the larger dust ejecta.
April 30, 2014 - Lance Benner and Marina Brozovic of JPL are planning observations of 209P/Linear with the
Goldstone radar facility May 26-30. This radar observes at a wavelength of 3.5 cm, detecting smaller meteoroids than Arecibo, which operates at a wavelength of 12.6 cm. Check the Goldstone Radar Facility page for updates once the observations are happening.
April 14, 2014 - The comet is on its way and active. Guido et al. posted this
image of 209P/Linear on April 14.95 UT, taken at the La Palma - Liverpool telescope when the comet was still magnitude +17. [More here]
April 7, 2014 - May issue of Sky & Telescope features a great article by Joe Rao on the May shower. The shower features the front cover under the title: "Meteor Storm Watch. Dark with a Chance of Fireballs".
March 30, 2014 - This website now features a new design of the "FLUXTIMATOR" applet, by David Nugent and Peter Jenniskens. The java applet enables you to calculate the apparent rate of meteors under clear skies and how that rate depends on observing location and conditions.
The comet first showed a tail in this March 19 image by Jean-Francois Soulier, France. [Other images]
March 18, 2014 - Interest in the possible new shower is growing. Article by Deborah Byrd in EarthSky.
March 5, 2014 - "If this is not exciting enough...": [The Movie]
February 17, 2014 - Comet 209P/Linear is now in the field of the STEREO spacecraft.
November 12, 2013 - Carl Hergenrother of the University of Arizona/Vatican Observatory captured this image of the approaching comet 209P/Linear. [Other images]
November 4, 2013 - Quanzhi Ye and Paul A. Wiegert publish an article in MNRAS called "Will Comet 209P/Linear generate the next meteor storm?" in which they analyse the activity of comet 209P/Linear in the previous orbit. They find that the ejected grains are relatively large (which could produce visible meteors). They confirm that the total dust production is less than that of many other known comets and estimate the same rate of 200 meteors per hour under ideal conditions as found by Vaubaillon. They re-emphasise the uncertainty about unknown past activity of the comet, as expressed before by Jenniskens and Lyytinen.
August 26-30, 2013 - Regina Rudawska and Peter Jenniskens published a paper from a meteoroid stream search in CAMS and SonotaCo video meteoroid orbits survey data, which was presented at the Meteoroids 2013 conference in Poznan, Poland. They identify a shower "Camelopardalids", given IAU number 451 and code "CAM", that has similar orbital elements to 209P/Linear, but the shower is active earlier in the month of May (solar longitude = 39).
October 9, 2012 - Sky&Tel article by Kelly Beatty.
Distribution of dust in Earth's path, calculations by Jeremie Vaubaillon
March 10, 2012 - Meteor astronomer Jeremie Vaubaillon of I.M.C.C.E. in Paris calculates that all dust trails of comet 209P/Linear created between 1803 through 1924 will be in Earth's path. Assuming typical activity of Jupiter-Family comets, Vaubaillon estimates between 100 and 400 meteors per hour at the peak.
Comet 209P/Linear photographed by Michael Jaeger on April 25, 2009
April 15.97, 2009 - Comet 209P/Linear returns to perihelion, rounding the Sun, and sprouts a short tail. The comet nuclear magnitude is +19.6, the total magnitude +16.1. That suggests a small size of only about 0.8 km.
Dec 1, 2008 An asteroidal object is seen again, now called 2008 X2, and recognized as a return of 2004 CB, earlier recognized as a (weakly active) comet. Later in December, the Minor Planet Center assigns the name 209P/Linear.
September 25, 2006 - "Meteor Showers and their Parent Comets" is published by Cambridge University press. It contains predictions of what to expect from unusual meteor showers in the next 50 years. For the year 2014, special attention is asked for the possible new May 24 shower [Hardcover]
October 9, 2004 - While working on the book "Meteor Showers and their Parent Comets", meteor astronomer Peter Jenniskens calculates a close miss-distance between Earth and comet dust ejected from 2004 CB, and asks Esko Lyytinen of Helsinki, Finland, to investigate possible dust trail encounters. They predict what may be the next big meteor shower just 5 days before the return of 2004 CB in 2014. These future "omicron Ursids" will have a slow 19.4 km/s apparent speed. Expected rate of meteors is unknown, because it depends on whether the comet was active in the past two centuries, before it was discovered.
March 30, 2004 - Rob McNaught discovers that the +16.7-17.0 magnitude object is weakly active. Using a 1.0-m reflector, he noticed a faint tail extending 1.1 arcminutes. The object is calculated to pass Earth at only 0.0554 AU (8,290,000 km, or 5,150,000 miles) on May 29, 2014, but due to its low activity is expected to brighten only to about magnitude +11. This will be the 9th closest approach to Earth of comets on record, if counting only those with reliable orbits. Comets that passed closer are the eta Lyrids comet IRAS-Araki-Alcock (in 1983), June Bootid comet 7P/Pons-Winnecke (1927), Andromedid comet Biela (1850), comet Lexell (1770), the comet of 1743, the comet of 1702, Leonid shower comet 55P/Tempel-Tuttle (1366), and Orionid shower comet 1P/Halley (837).
Febr. 3, 2004 - The automatic Near Earth Object survey "Lincoln Near-Earth Asteroid Research" (LINEAR) 1.0-metre (39 inch) telescope detects an asteroidal looking object, named 2004 CB, moving in a 5.02-year orbit.