Search for Planet Nine Lecture

Free ZOOM webinar: “The Search for Planet Nine” by Mike Brown (Caltech)

We would like to invite everyone to a free Zoom webinar on “The Search for Planet Nine” by Caltech planetary scientist Mike Brown this Friday, January 19, at 9 p.m. EST. Details of his talk are given below (PLEASE NOTE THE TIME ZONES). Mike is best known for his discovery of Eris and other TNOs.

To access the Zoom link, please register at:

Registration is free, quick and easy. All you have to do is to fill in your full name and email address, and the Zoom link will be sent to you automatically.

Neowise Over Plumas Lake

On July 13th 2020 I captured this image of Comet Neowise setting to the West at 9:15 pm. Canon 6d – 15 second exposure – 1250 ISO – 50mm lense

Neowise over Plumas Lake

C/2020 F3 or Comet NEOWISE is a long period comet with a near-parabolic orbit discovered on March 27, 2020, by astronomers during the NEOWISE mission of the Wide-field Infrared Survey Explorer space telescope. At that time, it was an 18th-magnitude object, located 2 AU away from the Sun and 1.7 AU away from Earth.
Orbital period: 6,766 years
Discovered: March 27, 2020
Orbits: SunLast perihelion: July 3, 2020
Dimensions: ~5 km (3 mi)
Number of observations: 376

Beam’ a Greeting to New Horizons!

Team to Transmit Messages to the Spacecraft During New Year’s Flyby in the Kuiper Belt

NASA’s New Horizons spacecraft has traveled 13 years to reach the heart of the Kuiper Belt – but you can get there in a matter of hours!

In 2005, more than 430,000 people signed up online to place their names on New Horizons for its trek to Pluto and beyond. Now, with the intrepid spacecraft in the “beyond” phase of its voyage and poised to conduct the farthest planetary flyby ever, NASA’s New Horizons mission team is offering the public another chance to send a message to New Horizons on its historic exploration of Ultima Thule — an ancient Kuiper Belt object a billion miles farther than Pluto!

Visit to select a message to send to the New Horizons spacecraft. You’ll be asked to confirm your submission through email, and you’ll receive an electronic certificate commemorating your participation.

On Jan. 1, as New Horizons is flying past Ultima Thule four billion miles from home, the messages and names will be “beamed” by radio toward the spacecraft and Ultima from the satellite communications facility at the Johns Hopkins Applied Physics Laboratory – on the same Maryland campus as New Horizons mission control!

“Traveling at light speed, the signals carrying these messages will reach the spacecraft about six hours after being beamed from the Applied Physics Lab’s largest dish antenna, on the very same day that New Horizons flies by Ultima Thule!” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute, Boulder, Colorado. “How cool is that?

Entries will be accepted through Dec. 21, 2018. Like the flyby itself, this is a one-shot chance to become part of deep-space exploration history – don’t miss it!

Aqua Caliente Star Party

One of my favorite places to hold a star party is in the desert east of San Diego. On Tuesday March 7th, 2017 I headed out to Aqua Caliente County Park to meetup with a dear friend Sandy H. and her band of home school parents and teachers. We had a lovely evening which started out with a tour of the night sky. This time of year we see the Orion complex on the meridian right after the sun sets. We started out viewing the Andromeda galaxy, and then we moved on to look at a few stars. Everyone likes to see the bright red Betelgeuse and the twinkling blue Cirrus.

From there we moved to Orion and looked at the great Orion nebula, M42. After everyone had a turn we then set the scope on the moon and let everyone take pictures with their phones through the eyepiece. I really enjoyed this group, they all took a great interest in the sky, and everyone had a great time.

I took a few hundred pictures over several hours and assembled this movie of the event.

And here are a few of my favorite shots from the night:

Astrometric Measurement of WDS 03117

I am pleased to present this paper that I co-authored with two teachers and submitted to JDSO this year as part of the Boyce Astro program.

Hilde van den Bergh1, Chris Olivas2, Jerry Hilburn3

  1. Mentor, BEWiSE, Fleet Science Center, San Diego, California, USA.
  2. Chris Olivas, High Tech Middle School, San Marcos, California, USA.
  3. Epsilon Orion Observatory, San Diego, California, USA.

Abstract: We report CCD astrometric measurements of the components of the double star system WDS 03117+8128 STF327AB using the iTelescope network. We find the relative position to be r = 20.26± 0.12 arc-sec and q = 289.1±0.39 degrees at epoch 2016.84. When combined with the historical data over the last 114 years the trend suggests the decreasing of the distance between the AB pair.

We used the Washington Double Star Catalog (WDS) to identify a binary pair on which to conduct angle (Theta) and separation (Rho) measurements. The double star system was selected based on the following requirements:;


  • must be observable from the Northern hemisphere in the autumn
  • an angular separation greater than six arc seconds
  • a magnitude difference of no more than 5


The catalog star WDS 03117+8128 (STF 327 AB), satisfied these criteria

The A star in STF 327 is a spectroscopic binary (WDS Notes). The B star is not part of the spectroscopic pair. The primary has a spectral type of A7III-IV (Sordiglioni, G.). That means the star is a (A) white (IV) subgiant. The difference in magnitude between the A and B stars is 4.75 with the primary star having a magnitude of 5.914 in the visible and the secondary star having a magnitude of 10.7 in the visible, according to SIMBAD data. The first position angle and separation measurements taken in 1902 were 282o and 25 arc-seconds, respectively. The last measurements were 289o and 21.2 arc-seconds, respectively, in 2003.


Equipment, Observations and Data Reduction Procedures

CCD images were taken using the T7 and T18 telescopes, part of the iTelescope network. T7 is a Corrected Dall-Kirkham Astrograph with an aperture of 431mm, a focal length of 2929mm, and a F/Ratio of f/6.8. The CCD for the T7 is a SBIG STL-11000M (ABG) with a resolution of 0.63 arc-secs/pixel housing an array 4008 by 2672 (10.7 Mega pixels) with a FOV of 28.2 x 42.3 arc-mins and is located in Nerpio, Spain.

Additional images were taken using the T18 telescope located in Nerpio, Spain, using a Planewave 0.32-m f/8.0 reflector equipped with a 3072 by 2048 array imaging at a pixel scale of 1.69?. Both cameras can easily resolve separations above five arc-seconds.

A total of six images were acquired between epochs 2016.816 and 2016.854. Two images were taken with the T7 Telescope each with red (1-90sec, 1-120sec). Four images were taken with the T18 Telescope, two images each with the red (1-90sec,1-120sec), hydrogen alpha (1-120sec, 1-180sec). An additional 11 images were excluded due to tracking quality of the observations.

The remaining 6 images were preprocessed (dark and flatcorrection) by the iTelescope data reduction pipeline. MaximDL v6 was used to insert World Coordinate System (WCS) positions into the FITS headers through comparison of the image star field against the Fourth U.S. Naval Observatory CCD Astrograph Catalogue (UCAC4).

During this process MaximDL typically used approximately 400 stars out of a database of 3000 stars for this particular star field. Mirametrics Mira Pro x64 was used to compute accurate position angles and separations of the component stars. The A and B stars were identified, marked, and then measured using the algorithms of Mira Pro to find the centroids of each component. The telescopes and filters used for the 6 images measured gave consistent results so we calculated a master average of r and q.

 See full paper for results: WDS03117-8128 STF 327 AB

Astrometric Measurements of WDS 20210+1028

I am excited to report the submission of a double star research paper to the Journal of Double Star Observations. I co-authored the paper with a team of College professors in the local San Diego area. This research project was part of an Astronomy Research Seminar offered by Cuesta College, supported by the Institute for Student Astronomical Research (InStAR), and conducted by Boyce Research Initiatives and Education Foundation (BRIEF).

As a proof of concept of our data analysis process, we decided to observe a double star system listed in the Washington Double Star Catalog (WDS) as having a “known” orbital solution. The double star system we selected had to be observable from the Northern hemisphere in June, with an angular separation greater than six arc seconds, and with a listed maximum magnitude difference of 2.5 between the stars. WDS 20210+1028 J838 (hereafter referred to as J 838) satisfied these criteria. Motivations for these criteria are discussed in the telescope selection section below.

Observations of J 838 were first reported by Jonckheere (1912), who found a separation of only 2.9?. Robert Jonckheere (1888-1974) discovered and published measurements of over 3000 doubles in a career spanning circa 1908 to 1962, as described in detail by Knapp (2016a).  Among others studying J 838 in the twentieth century, Jonckheere published four more observations between 1948 and 1958, which showed the pair’s angular separation increasing to 3.5?. Jonckheere (1952) noted (translated from French):

“Rapid movement on the arc clearly confirmed. This couple is probably formed by stars of very small mass located about 8 parsecs.”

Another veteran observer, George van Biesbroeck, made micrometer measurements of J 838 in 1966, and published them with measurements of other doubles in van Biesbroeck (1974). From that paper’s Introduction:

“The present measures are a continuation of previous ones (Van Biesbroeck 1966). They will be the last ones that I made. My present physical condition precludes further work at the telescope. There has been no change in the method of observing or the telescopes used, except that on my 90th birthday in 1970 I was granted the use of the 90-inch (2.3-m) Steward Observatory telescope on Kitt Peak.”

Note: Dr. Van Biesbroeck observed last on the nights of 1974 January 1 and 2 with the 84-inch (2.1m) telescope. He wrote the above paragraph and compiled his last manuscript in the same month just before his 94th birthday. Immediately thereafter his health failed rapidly and he died on 1974 February 23.

This final paper, published posthumously, marked the end of a remarkable career in astronomy that began in 1904 (Tenn 2012).

The first calculated orbital elements for J 838 were published by Olevi? (2002) and give a period of 239.84 years, with periastron occurring at 1967.510. Eccentricity, semi major axis and inclination were given as 0.784, 7.451? and 77.6°, respectively. The Sixth Catalog of Orbits of Visual Binary Stars (Hartkopf et al. 2011) classifies this orbit as category 5, “poorly determined”. The fitted orbit suggests that the pair is currently (2016) nearing maximum angular separation, which warrants further observations to more accurately constrain its shape and size.

The first CCD measurements (in 2001) were reported by Hartkopf et al. (2013), and the first published results for the system using speckle interferometry were by Mason et al. 2004. Cvetkovi?, and collaborators in Eastern Europe, made seven measurements of J 838 with CCD astrometry between 2009 and 2013 (see Cvetkovi? et al. 2016, and references therein). They also provide relative photometry (B and V band) for the pair: ?B = 0.35±0.02 mag, and ?V=0.06±0.01 mag.

Three earlier papers in JDSO include measurements of this system. Muller et al. (2006, 2007) report CCD astrometry from 2005, while Knapp (2016b) reported V-band photometry for A and B members of the pair (12.54±0.01 mag and 12.58±0.01 mag, respectively) based on 3-second exposures using iTelescope in 2015.

Read More>> The completed paper is available by download: JDSO Double Star Paper

New Telescope at Catfish Observatory

There are few places in America where you can go and not have Internet or Cell phone coverage. Today I will embark on a journey to such a place. Texas. Actually, not all of it, just McDonald Observatory near Fort Davis.

McDonald Observatory
McDonald Observatory

And of course I will driving across the desert at the hottest time of the year. I have prepared for it best I can and hope all goes well, because if it does I am bringing home a world class science tool that will allow me to explore the universe at the next level.

Say hello to my little friend! A 16″ RC that I will be picking up in West Texas on Saturday. Commissioning ceremony is planned for October when the heat should finally give way to cool nights and steady seeing.

16" ritchey chretien telescope
16″ ritchey chretien telescope


Asteroid TB145 Movie

Friday night I started calibration and testing of the imaging system at 8PM. By 10pm I was ready to start taking data on the Halloween Asteroid. When I first moved the scope into position and started shooting I tried a series of 60 second shots, then 30 second, then 10 second shots.

The challenge was finding the right exposure length to capture the asteroid as a point of light. At the longer intervals the asteroid appeared as a streak and even when I dialed it down to 10 seconds it still moved so fast that it took up 2-3 pixels of width. The sequence in the video below is a 12 minute long series of photos each 10 seconds long with a 5 second pause between shots.

Estimated visual magnitude at this time was 11.5. The rock was so near the moon that in the original images I could see streaking from the moonlight and vignetting on the edges of the images. I processed these shots individually and removed the streaking. I am amazed at how fast this asteroid moved through the field of view.

2015 TB145 – Big Rock Screams Past Earth Friday Night

I love a spectacle, or more precisely the high energy motion of a fast moving rock. Join me Friday night at TDS as we attempt to shoot asteroid TB145  as it screams past earth beginning at 10pm. The asteroid will appear just below the moon near Orion moving northeast. The asteroid will move 12 degrees in 6 hours passing under the moon brightening a full magnitude during its visible transit.


Though it is being reported as a Halloween flyby, you won’t be able to see it Saturday night as it will fade to 17th magnitude and rate of motion will slow considerably compared to Friday night.

Just for giggles I ran this bad boy through a Asteroid Impact Calculator and obtained these amusing results that you may find interesting. I included the Ephmerides below for Friday/Saturday UTC.

Assuming a distance from Impact: 100.00 km ( = 62.10 miles )
Projectile diameter: 650.00 meters ( = 2130.00 feet )
Projectile Density: 3000 kg/m3
Impact Velocity: 35.00 km per second ( = 21.70 miles per second )
Impact Angle: 60 degrees
Target Density: 2500 kg/m3
Target Type: Sedimentary Rock

The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 5.5 x 105years

Atmospheric Entry:

The projectile begins to breakup at an altitude of 65600 meters = 215000 ft
The projectile reaches the ground in a broken condition. The mass of projectile strikes the surface at velocity 34.7 km/s = 21.5 miles/s
The impact energy is 2.60 x 1020 Joules = 6.20 x 104MegaTons.
The broken projectile fragments strike the ground in an ellipse of dimension 0.926 km by 0.802 km

Crater Dimensions:

Final Crater Diameter: 15.2 km ( = 9.45 miles )
Final Crater Depth: 672 meters ( = 2200 feet )

Thermal Radiation:

Time for maximum radiation: 368 milliseconds after impact
Visible fireball radius: 12 km ( = 7.43 miles )
The fireball appears 27.2 times larger than the sun
Thermal Exposure: 1.14 x 107 Joules/m2
Duration of Irradiation: 2.76 minutes

Effects of Thermal Radiation at 100km.

Clothing ignites
Much of the body suffers third degree burns
Newspaper ignites
Plywood flames
Deciduous trees ignite
Grass ignites
Seismic Effects at 100km distance:
The major seismic shaking will arrive approximately 20 seconds after impact.
Richter Scale Magnitude: 7.8

Mercalli Scale Intensity at a distance of 100 km: 

Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken.

Damage slight in specially designed structures; considerable damage in ordinary substantial buildings with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned.


The ejecta will arrive approximately 2.4 minutes after the impact.
At your position there is a fine dusting of ejecta with occasional larger fragments
Average Ejecta Thickness: 13.4 cm ( = 5.28 inches )
Mean Fragment Diameter: 9.73 cm ( = 3.83 inches )

Air Blast:

The air blast will arrive approximately 5.05 minutes after impact.
Peak Overpressure: 98800 Pa = 0.988 bars = 14 psi
Max wind velocity: 171 m/s = 383 mph
Sound Intensity: 100 dB (May cause ear pain)

Damage Description:
Multistory wall-bearing buildings will collapse.
Wood frame buildings will almost completely collapse.
Glass windows will shatter.
Up to 90 percent of trees blown down; remainder stripped of branches and leaves.

Date             UT          R.A.           Decl.        Mag   Coord Motion     
                     h m s                                                     “/min    “/min  

2015 10 31 040000 04 54.57   +10 35.4  11.7  +44.26   +58.19

2015 10 31 050000 04 57.77   +11 38.0  11.6  +51.97   +67.28

2015 10 31 060000 05 01.54   +12 50.7  11.4  +61.55   +78.58

2015 10 31 070000 05 06.03   +14 16.1  11.3  +73.70   +92.81

2015 10 31 080000 05 11.45   +15 57.6  11.1  +89.52  +110.95

2015 10 31 090000 05 18.09   +17 59.8  10.9 +110.73  +134.36

2015 10 31 100000 05 26.40   +20 28.7  10.7 +140.21  +164.87

2015 10 31 110000 05 37.07   +23 32.7  10.6 +182.84  +204.79

2015 10 31 120000 05 51.26   +27 22.2  10.4 +247.40  +256.40

2015 10 31 130000 06 10.90   +32 09.5  10.2 +350.19  +319.86

2015 10 31 140000 06 39.46   +38 03.2  10.1 +521.73  +386.20

2015 10 31 150000 07 23.10   +44 51.6  10.1 +811.75  +419.80

2015 10 31 160000 08 30.97   +51 24.1  10.3+1240.33  +336.62

2015 10 31 170000 10 06.30   +55 00.0  10.7+1556.02   +68.29

2015 10 31 180000 11 45.91   +53 30.3  11.4+1346.68  -228.51

2015 10 31 190000 13 00.77   +48 23.9  12.2 +903.46  -353.92

2015 10 31 200000 13 49.21   +42 26.7  13.0 +575.57  -347.10

2015 10 31 210000 14 20.46   +37 03.8  13.8 +379.03  -295.92

2015 10 31 220000 14 41.50   +32 35.6  14.5 +262.01  -241.35

2015 10 31 230000 14 56.36   +28 58.2  15.1 +189.33  -195.19

2015 11 01 000000 15 07.30   +26 02.0  15.6 +141.94  -158.74

2015 11 01 010000 15 15.62   +23 38.0  16.1 +109.69  -130.51

2015 11 01 020000 15 22.14   +21 38.9  16.4  +86.95  -108.62

2015 11 01 030000 15 27.35   +19 59.2  16.8  +70.46   -91.52

2015 11 01 040000 15 31.62   +18 34.7  17.1  +58.22   -77.99

2015 11 01 050000 15 35.18   +17 22.3  17.3  +48.97   -67.16

2015 11 01 060000 15 38.20   +16 19.7  17.5  +41.89   -58.36

2015 11 01 070000 15 40.80   +15 25.0  17.8  +36.40   -51.14

2015 11 01 080000 15 43.08   +14 37.0  17.9  +32.09   -45.13

2015 11 01 090000 15 45.10   +13 54.4  18.1  +28.66   -40.08

2015 11 01 100000 15 46.92   +13 16.6  18.3  +25.90   -35.80

2015 11 01 110000 15 48.57   +12 42.7  18.4  +23.62   -32.13

2015 11 01 120000 15 50.08   +12 12.1  18.6  +21.71   -28.96

2015 11 01 130000 15 51.47   +11 44.6  18.7  +20.05   -26.22

2015 11 01 140000 15 52.75   +11 19.6  18.8  +18.58   -23.82

2015 11 01 150000 15 53.95   +10 56.9  18.9  +17.24   -21.71

2015 11 01 160000 15 55.05   +10 36.1  19.0  +15.98   -19.85

2015 11 01 170000 15 56.08   +10 17.1  19.1  +14.78   -18.22

2015 11 01 180000 15 57.03   +09 59.6  19.2  +13.63   -16.77

2015 11 01 190000 15 57.90   +09 43.5  19.3  +12.50   -15.48

2015 11 01 200000 15 58.69   +09 28.6  19.4  +11.42   -14.34