McDonald Observatory is an astronomical observatory located near unincorporated community of Fort Davis in Jeff Davis County, Texas, United States. The facility is located on Mount Locke in the Davis Mountains of West Texas, with additional facilities on Mount Fowlkes, approximately 1.3 kilometers (0.81 mi) to the northeast.[1] The observatory is part of The University of Texas at Austin. It is an organized research unit of the College of Natural Sciences.

McDonald Observatory
The observatory from the southeast. The Hobby–Eberly Telescope on Mt. Fowlkes (left) and the Harlan J. Smith and Otto Struve Telescopes on Mt. Locke (right).
Alternative names711 MC Edit this at Wikidata
Named afterWilliam Johnson McDonald Edit this on Wikidata
Organization
Observatory code 711 Edit this on Wikidata
LocationJeff Davis County, Texas
Coordinates30°40′17″N 104°01′19″W / 30.6714°N 104.022°W / 30.6714; -104.022
Altitude2,077 m (6,814 ft) Edit this at Wikidata
Established1933 Edit this on Wikidata
Websitemcdonaldobservatory.org Edit this at Wikidata
Telescopes
McDonald Observatory is located in the United States
McDonald Observatory
Location of McDonald Observatory
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The observatory produces StarDate, a daily syndicated radio program consisting of short segments related to astronomy that airs on both National Public Radio and commercial radio stations — about 400 affiliates in all.

History

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McDonald Observatory

McDonald Observatory was originally endowed by the Texas banker William Johnson McDonald (1844–1926), who left about $1 million — the bulk of his fortune — to The University of Texas at Austin to endow an astronomical observatory. Edwin Hockaday Fowlkes, step-son of the land's original owner John Chandler Prude, donated the land to the University of Texas to build the observatory. The provision of the will was challenged by McDonald's relatives, but after a long legal fight, the university received about $800,000 from the estate and construction began at Mt. Locke. The then-unnamed Otto Struve Telescope was dedicated on May 5, 1939,[2] and at that time was the second largest telescope in the world. McDonald Observatory was operated under contract by The University of Chicago until the 1960s, when control was transferred to The University of Texas at Austin under the direction of Harlan J. Smith.[3]

Research today at the McDonald Observatory encompasses a wide variety of topics and projects, including the search for and understanding of planetary systems, stars and stellar spectroscopy, the interstellar medium, extragalactic astronomy, and theoretical astronomy. The Hobby-Eberly Telescope Dark Energy Experiment, or HETDEX,[4] is a multi-year undertaking to decode the nature of dark energy.[5]

Directors[3]

Observatory

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Dome of the 10 m Hobby-Eberly Telescope. It houses one of the largest optical telescopes in the world.

McDonald Observatory is equipped with a wide range of instrumentation for imaging and spectroscopy in the optical and infrared spectra, and operates the first lunar laser ranging station. It works closely with the astronomy department of The University of Texas at Austin while maintaining administrative autonomy.[citation needed] The high and dry peaks of the Davis Mountains make for some of the darkest and clearest night skies in the region and provide excellent conditions for astronomical research.[citation needed]

 
Electric motors and position sensors at the Otto Struve Telescope at the McDonald Observatory, Texas

The Otto Struve Telescope, dedicated in 1939, was the first large telescope built at the observatory.[9][10] It is located on Mt. Locke at an altitude of 2,070 m (6,790 ft). The summit of Mt. Locke, accessed by Spur 78, is the highest point on Texas highways.[11] The Harlan J. Smith Telescope, also on Mt. Locke, was completed in 1968.[12][13]

The Hobby-Eberly Telescope (HET), dedicated in late 1997, is located on the summit of Mt. Fowlkes at 2,030 m (6,660 ft) above sea level.[14] It is operated jointly by The University of Texas at Austin, Pennsylvania State University, Ludwig Maximilian University of Munich, and Georg-August University of Göttingen.[15] As of 2019, after upgrades the HET is tied with the Keck Telescopes as the second or third largest telescope in the world. However, its cost was about 20% that of other similarly sized telescopes in use today due to its optimization for spectroscopy.

Additionally, The University of Texas at Austin is a founding partner of the international collaboration to build the Giant Magellan Telescope. McDonald Observatory administrators, scientists, and engineers are heavily involved in the endeavor. Director Taft Armandroff currently serves as Vice Chair to the GMT Board of Directors, and has served as chair.

Telescopes

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Domes of the 2.1 m Otto Struve Telescope (left) and 2.7 m Harlan J. Smith Telescope (right)

Currently, the observatory operates four research telescopes at its West Texas site:

A 0.9 m (36 in) telescope, formerly used for research, is now used for visitor programs.[18][19]

Tenant telescopes

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The two peaks also host a number of other instruments:

Former telescopes

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  • The 4.9 m (16 ft) Millimeter Wave Observatory (MWO) radio telescope operated on Mt. Locke until 1988.[23] MWO was a joint project between the UT Department of Astronomy and the Department of Electrical Engineering. The site of the dish antenna is now occupied by the BLOOMhouse, the UT School of Architecture's entry in the 2007 Solar Decathlon, which is now used for staff housing.[24]
  • The McDonald Laser Ranging System (MLRS) used a 0.76 m (30 in) telescope on Mt. Fowlkes from 1982 to 2019 for satellite laser ranging and lunar laser ranging.[25]

Climate

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The observatory experiences a semi-arid climate (Köppen BSk) with cool, dry winters and hot, wetter summers.

Climate data for Mount Locke, Texas (Jan 1, 1935–Mar 31, 2013)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °F (°C) 80
(27)
79
(26)
88
(31)
94
(34)
96
(36)
104
(40)
100
(38)
104
(40)
96
(36)
94
(34)
82
(28)
80
(27)
104
(40)
Mean daily maximum °F (°C) 53.5
(11.9)
56.9
(13.8)
63.7
(17.6)
71.4
(21.9)
78.6
(25.9)
84.5
(29.2)
82.7
(28.2)
81.3
(27.4)
76.6
(24.8)
70.5
(21.4)
61.2
(16.2)
54.4
(12.4)
69.6
(20.9)
Daily mean °F (°C) 42.7
(5.9)
45.4
(7.4)
51.0
(10.6)
58.3
(14.6)
65.5
(18.6)
71.4
(21.9)
70.8
(21.6)
69.8
(21.0)
65.5
(18.6)
59.3
(15.2)
50.0
(10.0)
44.0
(6.7)
57.8
(14.3)
Mean daily minimum °F (°C) 32.0
(0.0)
33.9
(1.1)
38.2
(3.4)
45.2
(7.3)
52.4
(11.3)
58.2
(14.6)
58.9
(14.9)
58.4
(14.7)
54.4
(12.4)
48.0
(8.9)
38.7
(3.7)
33.6
(0.9)
46.0
(7.8)
Record low °F (°C) −10
(−23)
−6
(−21)
4
(−16)
11
(−12)
26
(−3)
36
(2)
40
(4)
40
(4)
29
(−2)
13
(−11)
8
(−13)
−2
(−19)
−10
(−23)
Average precipitation inches (mm) 0.68
(17)
0.49
(12)
0.40
(10)
0.50
(13)
1.63
(41)
2.49
(63)
3.83
(97)
3.69
(94)
2.95
(75)
1.61
(41)
0.61
(15)
0.60
(15)
19.46
(494)
Average snowfall inches (cm) 1.9
(4.8)
0.8
(2.0)
0.2
(0.51)
0.1
(0.25)
0.0
(0.0)
0.0
(0.0)
0.0
(0.0)
0.0
(0.0)
0.0
(0.0)
0.1
(0.25)
0.4
(1.0)
1.2
(3.0)
4.7
(12)
Average precipitation days (≥ 0.001) 3.75 3.13 2.62 2.77 5.93 8.75 12.00 11.56 9.32 5.91 2.94 3.29 71.45
Source: Western Regional Climate Center, Desert Research Institute[27]

Visiting

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Inside the dome of the Harlan J. Smith telescope during a guided tour

The Frank N. Bash Visitors Center, located between Mt. Locke and Mt. Fowlkes, includes a gift shop and interactive exhibit hall. The Visitors Center conducts daily live solar viewings in a large theater and tours of the observatory's largest telescopes. It also hosts evening star parties, every Tuesday, Friday, and Saturday evening which allow visitors to look through numerous telescopes of various sizes in the Rebecca Gale Telescope Park.[28]

Special Viewing Nights, during which visitors can stay on-site (not required for the programs) and view directly through eyepieces on the 0.9 m and Struve (2.1m) telescopes, are held on a reservation-only basis.

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See also

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References

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  1. ^ "About | McDonald Observatory". McDonald Observatory. Retrieved 2012-01-10.
  2. ^ The Film & Video Archive of the McDonald Observatory. "Franklin Mountains and Dedication Ceremony (1939)". Texas Archive of the Moving Image.
  3. ^ a b Evans, David S., University of Texas at Austin McDonald Observatory, Texas State Historical Association
  4. ^ HETDEX
  5. ^ "UT Astronomy - Research". University of Texas at Austin Astronomy Program. Retrieved 2012-01-10.
  6. ^ McDonald Observatory Visitors Center Named for Former Director Dr. Frank N. Bash, The University of Texas McDonald Observatory, 2006-07-17
  7. ^ American Astronomical Society Confers Highest Honor on McDonald Observatory Director David Lambert, The University of Texas McDonald Observatory, 2007-02-05
  8. ^ Leading Astronomer Taft Armandroff Appointed New Director of McDonald Observatory, The University of Texas McDonald Observatory, 2014-01-14
  9. ^ "McDonald Observatory - 2.1-m Telescope". University of Texas at Austin Astronomy Program. Retrieved 2012-01-10.
  10. ^ "The Otto Struve Telescope | What Are Astronomers Doing? | McDonald Observatory". McDonald Observatory. Retrieved 2012-01-10.
  11. ^ Dindinger, Peter. (25 August 2009). "The Highest Point on Texas Highways". Retrieved 2012-01-10.
  12. ^ "McDonald Observatory - 2.7 m Telescope". University of Texas at Austin Astronomy Program. Retrieved 2012-01-10.
  13. ^ "The Harlan J. Smith Telescope | What Are Astronomers Doing? | McDonald Observatory". McDonald Observatory. Retrieved 2012-01-10.
  14. ^ "Hobby-Eberly Telescope". University of Texas at Austin Astronomy Program. Retrieved 2012-01-10.
  15. ^ "The Hobby-Eberly Telescope | What Are Astronomers Doing? | McDonald Observatory". McDonald Observatory. Retrieved 2012-01-10.
  16. ^ "UT Astronomy - 0.8 m Telescope". University of Texas at Austin Astronomy Program. Retrieved 2012-01-10.
  17. ^ "0.8-meter Telescope | What Are Astronomers Doing? | McDonald Observatory". McDonald Observatory. Retrieved 2012-01-10.
  18. ^ "UT Astronomy - 0.9 m Telescope". University of Texas at Austin Astronomy Program. Retrieved 2012-01-10.
  19. ^ "0.9-meter telescope | What Are Astronomers Doing? | McDonald Observatory". McDonald Observatory. Retrieved 2012-01-10.
  20. ^ "Welcome to MONET / Astronomie & Internet". University of Göttingen. Archived from the original on 2017-03-18. Retrieved 2010-10-02.
  21. ^ "BU Imaging Science - The Boston University 20-inch Telescope at McDonald Observatory". Boston University Center For Space Physics. Retrieved 2012-01-10.
  22. ^ "ROTSE Home Page". Robotic Optical Transient Search Experiment. Retrieved 2012-01-10.
  23. ^ "University of Texas at Austin, Department of Astronomy, Austin, Texas 78712-1083, McDonald Observatory, Fort Davis, Texas 79734. Report for the period 1 Sep 1988 - 31 Aug 1989". Bulletin of the Astronomical Society. 22 (1): 620. 1990. Bibcode:1990BAAS...22R.620.
  24. ^ Johnson, Rebecca (2008-05-01). "McDonald Observatory gets Solar BLOOMhouse « Know". Retrieved 2012-01-30.[permanent dead link]
  25. ^ Lightning strikes the McDonald Laser Ranging Station (MLRS) in Texas ILRS News 9/30/2019
  26. ^ "US COOP Station Map". Western Regional Climate Center, Desert Research Institute. Archived from the original on May 3, 2015. Retrieved May 3, 2015.
  27. ^ "MOUNT LOCKE, TEXAS (416104), Period of Record Monthly Climate Summary". Western Regional Climate Center, Desert Research Institute. Retrieved May 3, 2015.
  28. ^ "McDonald Observatory | Public Programs, Star Parties, Tours and Special Viewing Night". McDonald Observatory. Archived from the original on 2011-12-17. Retrieved 2012-01-10.
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