ALMANAC

Black Hills Astronomical Society

Notes by George Gladfelter

 

Changes may be shown in green or blue.

05/08/2017 - revised the note on religious observances and the listings in section 1.

04/10/2017 - section 7, and occultation data below slightly revised.

03/30/2017 - sections 1 and 7, and occultation data below slightly revised.

03/20/2017 - see section 7 and occultations.

03/16/2017 - revised tables in section 1.

03/14/201702/17/2017

02/12/2017

02/03/2017

01/27/2017

01/04/20176 - revisions made to the section for 2017.

Meteor Shower Calendar (Best viewing after midnight looking east.  Dates vary from year to year.)

Dates (maximum)     Shower Name

Jan 1-5 (3-4)              Quadrantids

Jan 15 - Feb 8 (7-8)    Alpha Aurigids

Apr 19-24 (22)           April Lyrids

May 1-12 (5)              Eta Aquarids

June 10-21 (15)          June Lyrids

Jul 15 - Aug 15 (28)    Delta Aquarids

Aug 1-18 (12)             Perseids

Oct 17-26 (20)            Orionids

Nov 14-20 (17)           Leonids

Dec 4-16 (13-14)        Geminids

 

1. Click here for the data (world wide) on moon phases, solar and lunar eclipses, equinoxes and solstices, lunar perigee and apogee, lunar perihelion and aphelion, and various data for Mercury, Venus, Mars, Jupiter, and Saturn for 2017-2020.  Also available is detailed data on solar eclipses for 2017-2018.  05/08/2017 editions.
Note: Copies of previous editions should be discarded.

 

2. Click here for revised sunrise, sunset, and twilight times at the Hidden Valley Observatory (for 2016-2019).  For an explanation of the table, click here.

 

3. Click here for times of moonrise, moonset, and transits of the moon (as seen from the Hidden Valley Observatory) and also the percentage of the moon's disk that is illuminated, and the Moon's declination, at 9 PM MST for 2016-2019.  Note: rising and setting times of any celestial object are subject to uncertainty due to topology, and especially variations in atmospheric refraction.  Also, the calculations are specific to a single location and cannot be easily adapted to locations more than a few miles away; therefore, treat the tabulated times for moonrise and moonset as approximations.  The other times listed are not affected by refraction, but are specific to the observer's longitude or position. Only phenomena that will be visible (assuming no clouds) are listed.

 

4. Click here for visibility of the moon and visible planets at dusk, midnight, and morning twilight (as seen from Hidden Valley Observatory and the nearby region) for 2015-2019.  Click here for an explanation of the table. Also, click here for times of rising, setting, and transit of the sun, moon, and bright planets in 2016-2019.  Included are the times for morning and evening twilight, the four phases of the moon, and the seasons (ME = March Equinox, JS = June Solstice, SE = September Equinox, DS = December Solstice).  Note: the rising and setting times are for the center of the sun, moon, or planet without correcting to the upper limb of the object; the twilight times are for when the sun is 15 degrees below the horizon - this is intermediate between nautical and astronomical twilight. Note well - this file is over 200 pages long.

 

5. Click here for a table listing the transit times of fourteen stars (as seen from Hidden Valley Observatory) for 2016-2019. This data can be used to easily calculate rising and setting times. Click here for an explanation of the table.

 

6. Click here for dates and times of Transits of Mercury 2016-2100.

 

7. Click here for a complete list of Lunar Occultations of bright planets and certain bright stars, and solar eclipses (2017-2020) revised 06/22/2017.

 

Listed below, for 2017-2020, you will find listings of astronomical phenomena with an emphasis on those events that will be visible from western South Dakota. - Note in particular the solar eclipse of August 21, 2017.  Note: lunar occultations are listed below only if visible from HVO. 

The Islamic dates listed below are tabular and may vary from observation at any particular location.

Distances to the Moon, the Sun, or to a planet are for Earth-center to object-center.

 

2017 (revisions made 11/23/2016 and 01/04/2017)

01/02 - 07:28:18 MST - Latest sunrise at HVO

01/04 7am MST - Perihelion 0.983309 a.u.

01/12 06:08 MST- Venus at greatest elongation, 47 E.

01/14 - Year 2770 Ab Urbe Condita starts (Roman)

01/19 3h MST - Mercury at greatest elongation 24 W.

01/28 - Chinese New Year (year of the Rooster) - see notes

02/10 - Partial Penumbral Lunar Eclipse, maximum at 17:44 MST, this eclipse will be in progress as the moon rises

02/26 - An annular solar eclipse (but not visible here)

03/04 (Saturday) - The moon (first quarter) will occult the star Aldebaran.  As seen from HVO: start 20:40:21.4 MST, middle 21:01:49.2, end 21:22:39.0

03/12 - MDT in effect

03/20 04:29 MDT - Spring Equinox

04/01 4h MDT - Mercury at greatest elongation 19 E.

04/07 - Jupiter at opposition

04/10 evening - Passover

04/16 - Easter Sunday

05/17 17h MDT - Mercury at greatest elongation 26 W.

05/26 evening - Ramadan

06/03 6h - Venus at greatest elongation, 46 W.

06/14 - Saturn at opposition this night

06/15 05:09:17 MDT - Earliest sunrise at HVO

06/20 22:24 MDT - Summer Solstice

06/20 - Longest day of the year at HVO: 15h 30m 7s

06/25 evening - Eid ul-Fitr

06/26 20:40:35 MDT - Latest sunset at HVO

07/03 - 14h MDT - Aphelion 1.0166756 a.u.

07/29 - 23h MDT - Mercury at greatest elongation 27 E.

08/07 - A partial lunar eclipse (maximum at 12:20) will not be visible here

08/21 (Monday) - A TOTAL Solar Eclipse (max. at 12:25:26 MDT) will be visible as close by as Alliance, NE. (See warning below!)
For observers at the Hidden Valley Observatory in Rapid City (MDT): at 10:27:05 a partial eclipse starts (elevation 45 degrees), at 11:49 the eclipse is nearly total (95.6%, 55 deg. elev., this is at 10:53 local solar time),
at 13:13:44 the local view of the eclipse ends.
(See warning below!)  If you want to do your eclipse watching only from Rapid City, this eclipse is the best you will get in your lifetime.
At a point near Alliance, NE a partial eclipse starts at 10:27:14 and ends at 13:13:44, with totality from 11:49:09.4 to 11:51:42.3 MDT (153 seconds).
For our friends in Sioux Falls - the eclipse will be partial starting at 11:38 CDT, max out at 92% at 13:01, and end at 14:26.  
(See warning below!)
If you are willing to travel anywhere in the USA to see a total solar eclipse, but miss this one, your next two chances will be 4/8/2024 and 8/12/2045 - but you will need to travel farther if you are starting from South Dakota.
You can use Google (or equivalent) to search for "2017 solar eclipse maps" to get a map showing where the eclipse is total - be warned: there will be lots of people standing right where you wanted to be.

09/12 - 4h MDT - Mercury at greatest elongation 18 W.

09/12 The moon (last quarter) will occult Aldebaran as the sun is rising; therefore, observing any of the event will not be easy; the start of the occultation, as seen at HVO, will be at 6:08:33.5 MDT.

09/16 - Mercury and Mars will be only about one fourth of a degree apart in the sky before sunrise.

09/20 evening - Year 5778 Anno Mundi starts (Jewish)

09/21 evening - Year 1439 Anno Hegira starts (Islamic)

09/22 14:02 MDT - Fall Equinox

09/29 evening - Yom Kippur

09/16 - Venus and Mars will be only about one fourth of a degree apart in the sky before sunrise.

11/05 - MST returns

11/05 As seen at HVO, the moon (2 days after full) will occult Aldebaran before moonrise, and the occultation will end at 18:59:10.3 MST.

11/23 - 17h MST - Mercury at greatest elongation 22 E.

12/09 - 16:14:42 MST - Earliest sunset at HVO

12/12 evening - Hanukkah

12/21 09:28 MST - Winter Solstice; Shortest day of the year at HVO: 8h 52m 38s

12/30 (Saturday) - The moon (2+ days before full) will occult the star Aldebaran.  As seen from HVO it will be visible part of the time: start 16:12:22.9 MST while the sun is nearing sunset, mid-occultation at 16:58:50.8 when the sun is 6 degrees below the horizon, ending at 17:07:51.5

Planets: Also see notes, below. Dates, in this section, refer to the date on which the night starts, "midnight" means the middle of the night, not always 12:00 A.M.  Comments pertain to observers in western South Dakota.

Pairings: 01/31 - Venus and the Moon (4.9 deg) at noon; 01/31 - Mars and the Moon (3.2 deg) at dusk; 3/20 - Saturn and the Moon (2.8 deg) at dawn; 05/22 - Venus and the Moon 3.4 deg at dawn and 3.4 deg at noon; 06/03 - Jupiter and the Moon (1.9 deg) at dusk; 06/20 -Venus and the Moon 3.8 deg at noon; 07/20 - Venus and the Moon 4.8 deg at noon; 09/16 - Mercury and Mars (0.23 deg) at dawn, 09/17 - Venus and the Moon 3.5 deg at noon;  09/26 -Saturn and the Moon 2.6 deg at dusk; 10/05 - Venus and Mars (0.23 deg) in the morning sky; 10/17 - Mars and the Moon 2 deg at dawn, and Venus and the Moon 3.7 deg at noon;  11/13 - Venus and Jupiter (0.3 deg) at dawn; 11/20 - Saturn and the Moon 2.4 deg at dusk; 12/04 - Mercury and Saturn at dusk; 12/17 - the Moon, Sun, and Venus will be close together at noon.

Mercury appears before dawn in early-January and fades by early-February, try about Jan. 12, magnitude about -0.1), then from early-September to late-September (best on Sep. 11-13, mag. about -0.5), and again in late-December (try Dec. 27-28, mag. -0.3). It will appear after sunset from mid-March to mid-April (try about March 31, mag. -0.2), then in early-July to early-August (not too good, try July 16-19, mag. 0), and finally mid-November to early-December (very poor).

Venus is an evening object from August, 2016 until late-March 2017, and then a morning object from later in March until late in November.  Venus will then not be visible until the mornings of late February in 2018.

Mars starts the year as an evening object, fades from view by mid-June, and reappears as a morning object in late-August.  In magnitude it will range from 1.5 to 0.9 in 2017.  For a good view of Mars - wait for 2018.

Jupiter starts the year as a morning object (mag. -2), and rises before midnight by late January. On April 4-17 it is visible from dusk till dawn until in late-June it sets before midnight and continues as an evening object until October. It reappears as a morning object in early November.  It will be brightest (-2.5) in April.

Saturn starts the year as a morning object. By mid-April it rises before midnight, and on June 9-20 it appears from dusk till dawn. Thereafter, it continues as an evening object until early-December.  Saturn will be brightest in 2017 (mag. 0) from early-June to late-June.

Note: "midnight" means middle of the dark, not always 12:00 A.M.

Full Moon Nights: 01/11, 02/10, 03/11, 04/10, 05/10, 06/08, 07/08, 08/07, 09/05, 10/05, 11/03, 12/02; but 12/31 will also be close to full.  (See notes below.)

 

2018

In 2018 and 2019 no lunar occultations at night of a planet or bright star will be visible from HVO.

01/01 13h MST - Mercury at greatest elongation 23 W.

01/01 - 19:24 MST - The full moon this evening is a "Super Moon" only 356,602 km from Earth.  See the note below on Super Moons.

01/02&03 - 07:28:18 MST - Latest sunrise at HVO

01/02 - 22:35 MST - Earth closest to the Sun (0.98328 au)

01/13 - Mercury and Saturn will appear close together in the sky before sunrise.

01/14 - Year 2771 Ab Urbe Condita starts (Roman)

01/31 (Wednesday) - Total Lunar Eclipse, maximum at 06:30 MST, the umbral phase starts at 04:48, and totality starts at 05:51, the total phase ends as the moon is setting at 7:08.

02/15 - A partial solar eclipse (but not visible here)

02/16 - Chinese New Year (year of the Dog) - see notes

03/03 - Mercury and Venus will be bright in the evening sky and only about one degree apart.

03/11 - MDT in effect

03/15 - 9h MDT - Mercury at greatest elongation 18 E.

03/20 - 10:15 MDT - Spring Equinox

03/30 - evening - Passover

04/01 - Easter Sunday

04/08 - Orthodox Easter

04/29 - 12h MDT - Mercury at greatest elongation 27 W.

05/08 - (18:39) MDT Jupiter at opposition

05/10 - 05:53 Jupiter appears closest to Earth (4.3998 au)

05/15 evening - Ramadan

06/14 evening - Eid ul-Fitr

06/14&15 - 05:09:19 MDT - Earliest sunrise at HVO

06/20&21 - Longest days of the year at HVO: 15h 30m 7s

06/21 - 04:07 MDT - Summer Solstice

06/26 - 20:40:36 MDT - Latest sunset at HVO

06/26 - Saturn at opposition this night (26th - 27th)

07/06 - 11h MDT - Earth farthest from the Sun (1.0167 au)

07/11 - 23h MDT - Mercury at greatest elongation 26 E.

07/12 - A partial solar eclipse occurs (but will not be visible here)

07/27 - Total lunar eclipse - not visible here

07/31 - 2h MDT - Mars appears closest to Earth (0.385 au)

08/11 - Partial solar eclipse (but not visible here)

08/17 - 12h MDT - Venus at greatest elongation, 45.9 E.

08/26 - 15h MDT - Mercury at greatest elongation 19 W.

09/09 evening - Year 5779 Anno Mundi starts (Jewish)

09/11 evening - Year 1440 Anno Hegira starts (Islamic)

09/18 evening - Yom Kippur

09/22 19:54 MDT - Fall Equinox

11/04 - MST returns

11/06 - 9h MST - Mercury at greatest elongation 23 E.

12/02 evening - Hanukkah

12/09 16:14:41 MST - Earliest sunset at HVO

12/15 - 4h MST - Mercury at greatest elongation 21 W.

12/21 - Mercury and Jupiter will be seen less than one degree apart in the sky before sunrise.

12/21 15:23 MST - Winter Solstice; Shortest day of the year at HVO: 8h 52m 38s

Planets: Also see notes, below. Dates, in this section, refer to the date on which the night starts, "midnight" means the middle of the night, not always 12:00 A.M.  Comments pertain to observers in western South Dakota.

Pairings: 01/06 - Mars and Jupiter 0.29 deg at dawn; 01/11 - Mars, Jupiter, and the Moon less than 5 degrees apart at dawn; 01/13 - Mercury and Saturn 0.8 deg at dawn; 02/11 - Saturn and the Moon (1.7 deg) before sunrise; 02/16 - Venus and the Moon 1.7 deg at noon; 03/03 - Mercury and Venus (1.1 deg) at dusk; 03/07 - Jupiter and the Moon 3.4 deg at midnight and 3.7 deg at dawn; 03/18 - Venus and the Moon 4.4 deg at noon and 4.1 deg at dusk; 04/02 - Mars and Saturn (1.3 deg) at dawn; 04/03 - Jupiter and the Moon 3.8 deg at dawn; 04/07 - Saturn and the Moon (1.1 deg) and Mars and the Moon (3.7 deg) at dawn; 06/16 - Venus and the Moon 5 deg at noon; 06/27 - Saturn and the Moon (1.1 deg) at dusk; 07/14 - Mercury and the Moon 2.4 deg at dusk; 07/15 - Venus and the Moon 4.8 deg at noon and 1.4 deg at dusk; 07/24 - Saturn and the Moon 1.7 deg at dusk and 1.2 deg later at midnight;  The Moon does a tour of Mercury (5 deg) dawn 09/08, Jupiter (3.8 deg) at dusk 09/13, Saturn (4.6 deg) at dusk 09/17, Mars 4.3 deg at dusk 09/19 and 4.1 deg at midnight;  10/14 - Saturn and the Moon (1.6 deg) at dusk; 11/11 - Saturn and the Moon 4 deg at dusk; 11/15 the Moon again visits Mars (2.9 deg) at dusk; 12/03 - the Moon and Venus 4.4 deg at dawn and 2.9 deg at noon; The Moon continues its tour: Mercury 4 deg at dawn on 12/05, Saturn 3.3 deg at dusk 12/08, and Mars 4.2 deg at dusk 12/14 for 12/17-25 - Mercury and Jupiter before sunrise, closest 0.9 deg on 12/21.

Mercury continues to be a morning object at the start of the year until January 19th, and then becomes an evening object in March, appearing highest at dusk in mid-March, and sinking out of view late in the month. Mercury next appears, again as an evening object from mid-June through July 20th, but fading in brightness throughout the period; it will be highest above the horizon at dusk during the last few days of June and the first few days of July. As a morning object, it will appear from mid-August until about September 10th growing brighter throughout; it will be highest in late August. It will be barely above the western horizon from November 5th through 13th, and then make a good appearance as a morning object throughout December, especially from the 10th through the 15th.

Venus will appear as an evening object about February 19th, appearing highest in late May, and sinking back toward the sun in late September. It will appear as a morning object in November, rising higher until about December 12th or so, and remain visible into 2019.

Mars, at the start of the year, rises before dawn. Late in May, Mars rises about midnight, and in late July becomes an all-night object brightening to magnitude -2.8. Thereafter Mars remains visible as an evening object fading to magnitude 0.5 by the end of the year.

Jupiter, at the start of the year, rises before dawn. By March 1st it rises by midnight, and in the first half of May is an all-night object at magnitude -2.5. Thereafter it is an evening object until early November. By December 10th it will appear again as a morning object.

Saturn appears in the sky early in the year, becoming an all-night object in late June, and then continues as an evening object until mid-December.

Full Moon Nights: 01/01, 01/30, 03/01, 03/30, 04/29, 05/28, 06/27, 07/27, 08/25, 09/24, 10/24, 11/22, 12/21&22.  (See notes below.)

 

2019

In 2018 and 2019 no lunar occultations at night of a planet or bright star will be visible from

HVO.

01/02&03 - 07:28:17 MST - Latest sunrise at HVO

01/02 - 22:20 MST - Earth closest to the Sun (0.98330 au)

01/05 - 16:34 to 20:49 MST a partial Solar Eclipse occurs that will not be visible here

01/14 - Year 2772 Ab Urbe Condita starts (Roman)

01/20 (Sunday) - 22:16 MST - The full moon this evening is a "Super Moon" only 357,714 km from Earth.  See the note below on Super Moons. Also, a Total Lunar Eclipse takes place as follows: 20:33:33 the umbral phase starts, 21:40:45 totality starts, 22:12:16 mid-point of the eclipse, 22:43:47 totality ends, 23:51:00 umbral phase ends.

02/05 (Tuesday) - Chinese New Year (year of the Pig) - see notes

02/15 - A partial solar eclipse (but not visible here)

02/26 - 18h MST - Mercury at greatest elongation 18 E.

03/10 - MDT in effect

03/20 - 15:58 MDT - Spring Equinox

04/11 - 14h MDT - Mercury at greatest elongation 28 W.

04/19 evening - Passover

04/21 - Easter Sunday

04/28 - Orthodox Easter

05/05 evening - Ramadan

06/04 evening - Eid ul-Fitr

06/10 - 09:28 MDT Jupiter at opposition

06/11 - 21:04 Jupiter appears closest to Earth (4.2839 au)

06/15&16 - 05:09:19 MDT - Earliest sunrise at HVO

06/21 - 09:54 MDT - Summer Solstice, longest day of the year at HVO: 15h 30m 8s.

06/23 - 17h MDT - Mercury at greatest elongation 25 E.

06/26&27 - 20:40:36 MDT - Latest sunset at HVO

07/02 - A total solar eclipse occurs, but will not be visible here

07/04 - 16h MDT - Earth farthest from the Sun (1.0168 au)

07/09 11h MDT - Saturn at opposition

07/16 - Partial lunar eclipse - not visible here

08/09 - 17h MDT - Mercury at greatest elongation 19 W.

08/31 evening - Year 1441 Anno Hegira starts (Islamic)

09/23 01:50 MDT - Fall Equinox

09/29 evening - Year 5780 Anno Mundi starts (Jewish)

10/08 evening - Yom Kippur

10/19 - 22h MDT - Mercury at greatest elongation 25 E.

11/03 - MST returns

11/11 - A solar transit by Mercury will be in progress as the sun is rising. Mercury will be nearest the center of the sun at 8:20:22.3 MST, will start egress from the sun's disk at 11:02:53.2, and complete the egress at 11:04:34.4 as seen from HVO. The next two transits will be in 2032 and 2039, but will not be visible here.  The transit of 2049 will again start before local sunrise as in 2019.

11/28 - 3h MST - Mercury at greatest elongation 20 W.

12/09 - 16:14:40 MST - Earliest sunset at HVO

12/21 21:19 MST - Winter Solstice;

12/21&22 - Shortest days of the year at HVO: 8h 52m 38s

12/22 evening - Hanukkah

12/25 - an annular solar eclipse will occur, but will not be visible here

Planets: Also see notes, below. Dates, in this section, refer to the date on which the night starts, "midnight" means the middle of the night, not always 12:00 A.M.  Comments pertain to observers in western South Dakota.

Pairings: 01/01 - Venus and the Moon 3.8 deg at dawn and 2.1 deg at noon then the Moon and Jupiter 4 deg at dawn 01/03 then with Mercury 2.4 deg at dawn 01/04; Venus and Jupiter at dawn 01/18-26 closest on 01/22 (2.4 deg); 01/31 - Venus and the Moon 1.5 deg before sunrise and 0.8 deg at noon; 02/02 - Saturn and Moon 3.7 deg at dawn; 2/18 - Venus and Saturn (1.1 deg) before dawn and fairly close 02/14-22; 2/27 - Jupiter and the Moon (1.6 deg) at dawn; 03/02 - Venus and the Moon 2.5 deg at noon; 4/23 - Jupiter and the Moon (0.8 deg) at dawn; 4/25 - Saturn and the Moon (1.9 deg) at dawn; 05/02 - Venus and the Moon 4.1 deg at noon; 05/07 - Mars and the Moon 3.7 deg at dusk; 06/01 - Venus and the Moon 3.6 deg at noon; 6/18 Mercury and Mars 0.3 deg at dusk and remaining close through July 5th; 06/19 - Saturn and the Moon start the day 2.2 deg apart and are still only 3.4 deg apart at dawn; 07/01 - Venus and the Moon 2.8 deg at noon; 07/03 Mercury, Mars and the Moon are less than 4.9 deg apart at dusk, then Mercury and Mars remain close through July 5th; 7/15 - Saturn and the Moon 1.9 deg at dusk and 1.1 deg later at midnight; 7/31 - Venus and the Moon 1.02 deg at noon - but less than 5 deg from the Sun; 08/09 - Jupiter and the Moon 2.3 deg at dusk; 08/11 - Saturn and the Moon 3.6 deg at dusk and 2.1 deg at midnight following; 08/30 Venus, the Moon, and the Sun close together at noon; 09/29 - Venus and the Moon 4.1 deg at noon; 10/03 - Jupiter and the Moon 2.3 deg at dusk; 10/29 - Venus and the Moon 3.7 deg at noon; 11/24 - Mars and the Moon 3.9 deg at dawn; 11/24 Venus and Jupiter (1.5 deg) at dusk; 11/28 - Venus and the Moon (1.06 deg) at noon; 11/29 - Saturn and the Moon 2 deg at dusk; 12/10 - Venus and Saturn (1.9 deg) at dusk; 12/28 - Venus and the Moon 3.6 deg at noon.

Mercury starts the year as a morning object for three mornings, and then appears in the evening in mid-February growing higher, but dimmer, until late February when it starts to sink and disappears by March tenth.  It will reappear as a morning object in late March and early April - but will be dim and low on the eastern horizon.  Very late in May it will reemerge as an evening object, starting bright and low but growing dimmer and higher until mid-June, then sink back toward the Sun and disappear in early July.  In late July it will reappear in the morning sky growing brighter day by day and reaching its highest on August 13th and sinking back out of view by August 25th or so.  Its final appearance of the year will run on the mornings of mid-November to mid December growing brighter and higher until December 4th, then sinking back toward the sun, but remaining bright.

Venus will be a bright morning object as the year starts, but by April will be low on the horizon and slowly sink out of sight by late May.  It will reemerge as an evening object in late October, and remain as a nice evening object into 2020.

Mars, at the start of the year, is an evening object high in the sky but gradually growing dimmer night by night.  By mid-July it will be lost until late September when it will reappear as a morning object, but dimmer than it was at the start of the year.

Jupiter, at the start of the year, is a morning object. By mid-April it rises by midnight, and by early June is an all-night object at magnitude -2.6. Thereafter it is an evening object until early December.

Saturn appears in the morning sky early in the year, becoming an all-night object in early July, and then continues as an evening object until the end of the year.

Full Moon Nights: 01/20, 02/18, 03/20, 04/18, 05/18, 06/16, 07/16, 08/14, 09/13, 10/13, 11/11, 12/11.  (See notes below.)

2020

01/02&03 - 07:28:15 MST - Latest sunrise at HVO

01/05 - 00:48 MST - Earth closest to the Sun (0.9832436 au)

01/10 - A partial Lunar Eclipse occurs that will not be visible here

01/14 - Year 2773 Ab Urbe Condita starts (Roman/Julian calendar)

01/25 (Saturday) - Chinese New Year (year of the Rat) - see notes

02/10 7h MST - Mercury at greatest elongation, 18 E.

02/18 - The Moon (2+ days past last quarter) will occult the planet Mars; as seen from HVO, the occultation will be partial from 04:45:18.8 to 04:45:31.7 MST and then be total until 06:05:41.1 with the partial phase ending 06:05:55.3 MST.

03/08 - MDT in effect

03/19 21:50 MDT - Spring Equinox

03/23 - 20h MDT - Mercury at greatest elongation 28 W.

04/08 evening - Passover

04/12 - Easter Sunday

04/19 - Orthodox Easter

04/23 evening - Ramadan

05/23 evening - Eid ul-Fitr

06/04 - 7h MDT - Mercury at greatest elongation 24 E.

06/05 - a partial Lunar Eclipse occurs that will not be visible here, nor noticeable anywhere

06/14 - 05:09:18 MDT - Earliest sunrise at HVO

06/20 15:44 MDT - Summer Solstice, longest day of the year at HVO: 15h 30m 8s.

06/20-21 MDT - An Annular Solar Eclipse occurs that will not be visible here

06/25&26 - 20:40:37 MDT - Latest sunset at HVO

07/04 6h MDT - Earth farthest from the Sun (1.0167 au)

07/04 21:07 to 23:53 MDT - A partial penumbral lunar eclipse occurs, but will not be noticeable

07/14 2h MDT - Jupiter at opposition

07/15 4h MDT - Jupiter appears closest to Earth (4.1393 au)

07/20 16h MDT - Saturn at opposition

07/22 - 9h MDT - Mercury at greatest elongation 20 W.

08/12 18h MDT - Venus at greatest elongation, 45.8 W.

08/19 evening - Year 1442 Anno Hegira starts (Islamic)

09/18 evening - Year 5781 Anno Mundi starts (Jewish)

09/22 07:31 MDT - Fall Equinox

09/27 evening - Yom Kippur

10/01 - 10h MDT - Mercury at greatest elongation 26 E.

10/05 - Mars appears closest this evening

10/13 17:26 MDT - Mars at opposition

11/01 - MST returns

11/10 - 10h MST - Mercury at greatest elongation 19 W.

11/30 00:32 to 04:54 MST - A partial penumbral lunar eclipse occurs, but will not be noticeable to the eye

12/08&09 - 16:14:40 MST - Earliest sunset at HVO

12/12 - The Moon (2 days short of new) will occult the planet Venus late in the afternoon; at 14:24:22.7 the partial phase will begin, and the occultation will be total at 14:24:52.4, but the Moon will be very low near the horizon and below the horizon before the occultation ends.

12/14 - A total solar eclipse occurs, but will not be visible from anywhere near here

12/20&21 - Shortest days of the year at HVO: 8h 52m 37s

12/21 03:02 MST - Winter Solstice;

12/10 evening - Hanukkah

 

Planets: Also see notes, below. Dates, in this section, refer to the date on which the night starts, "midnight" means the middle of the night, not always 12:00 A.M.  These comments apply to observers in western South Dakota.

Pairings: 01/20 - the Moon and Mars are 3.2 degrees apart at dawn; 02/18 the Moon and Mars 0.3 deg at dawn; 02/19 - the Moon and Jupiter 3.4 deg at dawn; 02/20 the Moon and Saturn 2.5 deg at dawn; 03/18 - the Moon and Mars 2.8 deg at dawn, the Moon and Jupiter 2.7 deg, and Mars and Jupiter 1.3 deg; 03/20 - Mars and Jupiter 0.7 deg at dawn; 03/31 - Mars and Saturn 0.9 deg at dawn; 05/12 - the Moon and Jupiter 3.1 deg at dawn; 05/15 - The Moon and Mars 4.9 deg at dawn; 05/18 - Jupiter and Saturn 4.7 deg at dawn; 05/21 - Mercury and Venus 1 deg at dusk; 05/23 - The Moon and Venus 4.3 deg at dusk; 06/08 - The Moon and Saturn 4.3 deg at midnight; 06/19 - the Moon and Venus 1.5 deg at dawn; 07/06 - The Moon and Saturn 3.3 deg at dawn; 08/01 - the Moon and Jupiter 3.2 deg at dusk; 08/08 - The Moon and Mars 1.6 deg at midnight; 08/28 - the Moon and Jupiter 2.3 deg at dusk and 3.1 deg at midnight; 09/05 - the Moon and Mars 1.4 deg at midnight; 10/02 - the Moon and Mars 1.8 deg at midnight; 10/22 - The Moon and Saturn 4.1 deg at dusk; 12/12 - the Moon and Venus 1.4 deg at noon; 12/21 - Jupiter and Saturn 0.1 deg at dusk.

Mercury appears in the evening in late-January growing higher, but dimmer, until February 12th when it is highest then starts to sink and disappears around February 21st. tenth.  It will reappear as a morning object in around March 4th, appear highest (but very low) around March 13th, and disappear before the end of March. It will reappear low and bright in the evening around May 13th, growing higher and dimmer until the end of May, disappear by mid-June. As a morning object, it will reappear around July 12th growing higher and brighter until July 25 or 26, and then sink while sinking until it is lost around August 8th. Its last apparition of the year will start around October 25th, then growing higher and brighter until November 9th after which, still bright at magnitude -0.7 it will sink out of sight at the end of November.

Venus will be a bright evening object as the year starts, but by late May sink out of sight. It will reemerge in mid-June, and remain as a bright morning object into 2021.

Mars, starts the year as a morning object, and gradually grows brighter but lower morning after morning.  By mid-March it will turn around and start appearing higher each morning while still growing brighter until in mid-August it starts to appear a little lower each day at dawn while still growing brighter until mid October when it becomes a full fledged evening object and starts to fade. It will remain an evening object into the next year.

Jupiter will appear as a morning object in mid-January and then grow in brightness to magnitude -2.8 in mid-July when it will be an all-night object. It will then become an evening object, and fade to -2.0 by the end of the year.

Saturn appears in the morning sky early in February, becoming an all-night object in mid-July, and then continues as an evening object into 2021.

Full Moon Nights: 01/10, 02/08, 03/08, 04/07, 05/06, 06/05, 07/04, 08/02, 09/01, 10/01, 10/30, 11/29, 12/29.  (See notes below.)

 

 

NOTES:

 

Observing The Sun -- WARNING  --  WARNING  --  WARNING !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Extreme caution must be used by anyone trying to view the sun.  You must block most of the visible light, and virtually all of the UV and infra-red coming from the sun.  Viewing the sun is inherently dangerous.  Dark photographic negatives are NOT designed to reduce sunlight to a safe level, especially UV and IR!  If a filter slips off your telescope or your binoculars your eye can be permanently damaged before you can react. Sunlight concentrated by a lens or telescope can overheat a filter causing it to melt or crack, and then you or your equipment will be at severe risk; therefore, sunlight must be filtered BEFORE entering any optical instrument or camera. Prolonged viewing of the sun requires great care and knowledge.  Viewing the sun safely requires previous study and setting up the equipment well in advance. Last minute preparation is likely to lead to disaster!  Please be sure you know what you are doing, and that you have the proper equipment with secure attachments if you wish to view or record solar phenomena. Do not hesitate to seek help from an experienced observer.

 

About the dates of religious observances: These dates are conceptually tied to astronomical phenomena, and cannot be simply predicted.  In the case of Christian and Jewish festivals the dates are determined by rigorous, but complicated, mathematics.  In the case of Islamic observances, many adherents believe that the calendar can only be determined from direct observation in each community; the dates shown here are determined mathematically and can differ from direct observation by no more than a day or two.  The numbering of years in the Roman system (A.U.C.), although relatively simple, is also shown because of its historical importance.  For a table showing the dates of Ash Wednesday, Easter, and Eastern Orthodox Easter for 1900-2100 click here. For the dates of the Chinese New Year, see the note below.

 

About visibility of the planets: The narrative provided here is specific to the latitude of the Hidden Valley Observatory, and should be reasonably accurate for latitudes between 42 and 46 degrees north, but increasingly inaccurate for observers farther north or south. The dates given are for the date on which a given night begins.  The times given are for the end of evening twilight (E), the middle of the night (m), and the start of civil twilight in the morning (M); they are specific to the vicinity of the observatory.  The elevation of a planet above the horizon is given in degrees for those times - if the planet's elevation is at least 3 degrees. Click here for more detailed information.

 

About Full Moon Nights: On the night of a full moon, and for a few nights before and after, the brightness of the moon may hinder observation of objects other than the moon.  It occasionally happens that two nights in succession "enjoy" being about equal in moon brightness. Click here for more detailed information on visibility of the moon (corrected 10/14/2016).

 

About "Super Moons":  The Moon is "full" when it is 180 degrees away from the Sun (in right ascension) and thus appears fully illuminated.  However, its distance (from the Earth's center to the Moon's center) varies as the Moon moves in its orbit, and ranges from less than 357,000 km (at perigee) to more than 406,000 km (at apogee).  Naturally, it appears bigger when it is closer, and the popular press has taken to calling a full moon near a perigee that is particularly close to the Earth a "Super Moon".  In this discussion, particularly close will be defined as closer than 357,000 km.  The full moon of September 27, 2015 in the evening at a distance of 356,878 km thus qualifies as a Super Moon, and the next one will be on the morning of November 14, 2016 at 356,520 km - this will be the closest Super Moon until 2034, but there will be less notable Super Moons in 2018, 2019, 2025, 2026, 2028, 2029, 2032, and 2033 also.

 

About Lunar Occultations:  The moon can, for a time, block an observer's view of a star or a planet.  Only occultations of bright stars and bright planets are listed here; and then only if the event is visible for an observer at the Hidden Valley Observatory.  The timing of an occultation is highly dependent on the observer's location, and is very sensitive to any inaccuracies in the computation of the coordinates of the moon and the star or planet involved.  Therefore, accurate times for actual observations are of great interest.  A extensive listing of lunar occultations is available here.

 

About Chinese New Year: This is determined by the date and time in China (GMT+8 hours) and is assigned to the date when a new moon first occurs on or after January 21.  The last possible date for this is February 20.  Once this date is calculated according to Chinese time, the same date is used also in the United States and the rest of the world (although, as an example, 6 PM in the evening on January 21 in San Francisco corresponds to 10 AM on the 22nd in China; moreover, it seems that celebrations outside of China may indeed start according to the time in China rather than local date-time).  No correction for the equation of time is made when computing the date of the new year, i.e. the calculations are referenced to GMT+8 hours, not local solar time on a selected meridian.  The actual time of day for the new moon is irrelevant unless it is so close to midnight as to introduce an ambiguity as to the date.  For a listing of the dates from 2015 through 2050, click here.

 

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