Black Hills Astronomical Society

ALMANAC

Black Hills Astronomical Society

Notes by George Gladfelter

05/26/2019

Changes may be shown in green or blue.

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 2019-2022. Also available are detailed data on solar eclipses for 2019-2020. April, 2019 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 2018-2021). 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 2018-2021. 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. The planets are best placed for observing from the Earth when farthest from the Sun. For Mercury and Venus this is the time of greatest separation or elongation (they are not exactly the same), and for the others the time called opposition (this is the time when the planet's right ascension is 180 degrees away from the Sun's). For a table of these times for 2018-2025 click here. Revised and extended 7/15/2018.

5. Click here for a table showing data at dusk, the middle of the night, and dawn for the sun, moon, and the five bright planets for each night 2018-2021. If the moon, or a planet, is within five degrees of a planet, another line of data shows the visual separation of the pair. Click here for an explanation of the table. Also, click here for times of rising, setting, and transit (marked "r", "s", or "t") of the sun, moon, and bright planets in 2018-2021. 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 150 pages long.

6. Click here for a table listing the transit times of twenty stars (as seen from Hidden Valley Observatory) for 2018-2021. These data can be used easily to calculate approximate rising and setting times. Click here for an explanation of the table.

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

8. Click here for a complete list of Lunar Occultations of bright planets and certain bright stars, and solar eclipses (May, 2019-2021) with data for observers at the Journey Museum in Rapid City as appropriate. revised 05/26/2019.

9. Posted here is a text file giving the coefficients for apparent Right Ascension, Declination, Distance, and Horizontal Parallax of the Moon for 2019-2020. The distance is the true distance (light time not factored in) in kilometers. The angular coordinates are in degrees. Each quantity is to be computed as:

quantity = A₀ + A₁x + A₂x² + ... + A₅x⁵

where x = h/24 with h = time in hours
thus, x varies from 0.0 up to +1.0.

The results for the angular quantities should agree very closely with the tabulated values in the Astronomical Almanac, and the distance should be consistent within a few meters.
See the notes section at the bottom of this page.

10. For 2019-2022, astronomical phenomena are listed below with an emphasis on those events that will be visible from western South Dakota. 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, Sun, or a planet are for Earth-center to object-center.

2019 corrected 01/02/2019

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

01/02&03 - 07:28:18 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 calendar)

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: 20:33:34 the umbral phase starts, 21:40:45 totality starts, 22:12:17 mid-point of the eclipse, 22:43:50 totality ends, 23:51:01 umbral phase ends.

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

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 (magnitude -2.6) at opposition

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

06/15 - 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, as seen from HVO. Mercury will appear nearest the center of the sun at 8:20:23.3 MST, will start egress from the sun's disk at 11:02:50.1, and complete the egress at 11:04:31.3. (These times were recomputed in April, 2019 but remain slightly uncertain because of uncertainty in Delta-T.) The next two transits will be in 2032 and 2039, but will not be visible from this area. 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 - 07:28:18 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 04:45:21.3 to 04:45:34.0 MST and then be total until 06:05:44.7 with the partial phase ending 06:05:58.9 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&15 - 05:09:19 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 - 16:14:39 MST - Earliest sunset at HVO

12/10 evening - Hanukkah

12/12 - The Moon (2 days short of new) will occult the planet Venus late in the afternoon; at 14:24:23.5 the partial phase will begin, and the occultation will be total at 14:24:53, but the Moon will be below the horizon before the occultation ends. EXTREME CAUTION IS ESSENTIAL when viewing an event near the Sun. See the warning below. Because you will be using little, if any, filtration, you must block the light from the Sun. If using a telescope, you must take care to never allow the Sun to enter your (or your camera's) field of view.

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

12/21 03:02 MST - Winter Solstice - Shortest days of the year at HVO: 8h 52m 56s

12/21 11:21 MST - Jupiter and Saturn are closest together at only 0.10 degrees apart. This is a fairly rare event (last time was in 2000, next time is in 2040). At 6 PM MST on the 20th, as seen at HVO, the pair are only 0.13 degrees apart, but very low above the SW horizon.

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

2021

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

01/02 - 06:51 MST - Earth closest to the Sun (0.983257 au)

01/14 - Year 2774 Ab Urbe Condita starts (Roman/Julian calendar)

01/23 19h MST - Mercury at greatest elongation, 18.6° E.

02/12 (Friday) - Chinese New Year (year of the Ox) - see notes

03/06 - 4h MST - Mercury at greatest elongation 27.3° W.

03/14 - MDT in effect

03/20 03:37 MDT - Spring Equinox

03/27 evening - Passover

04/04 - Easter Sunday

04/12 evening - Ramadan

05/02 - Orthodox Easter

05/12 evening - Eid ul-Fitr

05/16 - 23:54 MDT - Mercury at greatest elongation 22° E.

05/26 - a Total Lunar Eclipse: first contact of the umbra at 3:45 MDT, totality starts at 5:09 and ends at 5:28 after the Moon has set and the Sun has risen.

06/10 - An Annular Solar Eclipse occurs that will not be visible here. The eclipse starts as a partial at 2:12 MDT, as an annular at 3:50, is maximal (89.2%) at 4:43, reverts to partial at 5:34, and concludes at 7:11. The best view is at 80.8° N, 66.5° W.

06/14&15 - 05:09:18 MDT - Earliest sunrise at HVO

06/20 21:32 MDT - Summer Solstice, longest day of the year at HVO: 15h 30m 9s.

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

07/04 - 14h MDT - Mercury at greatest elongation 21.6° W.

07/04 16h MDT - Earth farthest from the Sun (1.01673 au)

08/19 18h MDT - Jupiter at opposition

08/19 23h MDT - Jupiter appears closest to Earth (4.0132 au)

08/02 0h MDT - Saturn at opposition

08/09 evening - Year 1443 Anno Hegira starts (Islamic)

09/06 evening - Year 5782 Anno Mundi starts (Jewish)

09/13 - 21h MDT - Mercury at greatest elongation 26.8° E.

09/15 evening - Yom Kippur

09/22 13:21 MDT - Fall Equinox

10/24 23h MDT - Mercury at greatest elongation 18.4° W.

10/29 15h MDT - Venus at greatest elongation, 47.0° E.

11/07 - MST returns

11/19 - A partial lunar eclipse occurs. The umbral phase starts 00:18 MST, reaches a maximum of 99.4% at 02:03, and leaves the umbra at 03:47:30.

11/28 evening - Hanukkah

12/04 - A total solar eclipse occurs, but will not be visible from anywhere near here. The best view will be at 00:33:27 MST as seen from 76.8°S, 46.1°W. Magnitude 1.019.

12/09 - 16:14:39 MST - Earliest sunset at HVO

12/20 - Shortest day of the year at HVO: 8h 52m 36s

12/21 08:59 MST - Winter Solstice;

Pairings: Most of January - Jupiter and Saturn; on the evening 1/09 - Mercury and Saturn 1.6°; 1/10 - Mercury and Jupiter; 1/11 - Mercury and Venus; mornings early February - Venus and Saturn (0.5° on 2/06); 2/11 Venus and Jupiter 0.4°; late Feb. through early March - Mercury and Jupiter (0.4° on 3/05); evening of 3/19 - Moon and Mars 3.6°; morning 4/06 - Moon and Saturn 4.9°; evenings late April - Mercury and Venus (1.2° on 4/25); evening of 5/12 - Moon and Venus 1.6°; next evening - Moon and Mercury 3.7°; evening of 5/15 - Moon and Mars 1.9°; evenings of late May - Mercury and Venus (0.4° on 5/28); evng 6/11 - Moon and Venus; evng 6/13 - Moon and Mars; morning 6/27 - Moon and Saturn; evenings July 4- 21 - Venus and Mars (0.5° on 7/12); morning 7/08 - Moon and Mercury; evng 7/11 - Moon and Venus; evng 8/08 - Moon and Mercury, and next evng Moon and Mars; evngs 8/14-23 - Mercury and Mars (0.1° on 8/18); evng 8/20 - Moon and Saturn; 8/21-22 - Moon and Jupiter; evng 9/07 - Moon and Mars; evng 9/08 - Moon and Mercury; evng 0/09 - Moon and Venus; evng 9/16 - Moon and Saturn; night of 9/17 - Moon and Jupiter; evng 10/09 - Moon and Venus; morning 10/11 - Mercury and Mars 3.7°; morning 11/03 - Moon and Mercury; mornings 11/05-15 - Mercury and Mars (1° on 11/10); evng 12/06 - Moon and Venus; evenings 12/27-29 - Mercury and Venus (4.2° to to 4.7°); morning 12/31 - Moon and Mars.

Mercury: Evenings January to early Feb. but best late January. Then mornings mid to late Feb. but poor. Again an evening object from late April to late May, perhaps best May 12-16. A poor showing in the mornings of late June to July 20+ - but growing brighter though never high. A very difficult showing in the evenings late summer, then somewhat better on the mornings of late October to early November, but again never very high above the horizon.

Venus starts the year as a morning object low on the horizon, sinking lower day by day, and becomes an evening object in late April but gains height above the horizon very slowly ( 15° at civil twilight's end by late November) and finishes the year as barely above the horizon at year's end.

Mars starts the year as an evening object at magnitude -0.1, but sets before sunrise and gradually becomes less bright until by April it's 1.3 in magnitude and near setting at midnight. Thereafter, Mars sets earlier and earlier, declines to magnitude 1.8, and fades from view in August. Mars reappears as a morning object in November.

Jupiter starts the year showing briefly in the evening sky before setting. It is then lost in the Sun's glare until March when it becomes a morning object. By early June, it rises as a bright object (-2.5 mag.) in the middle of the night, and in mid-August is at its brightest (-2.9). By mid-November, Jupiter sets before midnight, but continues as an evening object into 2022.

Saturn starts the year briefly visible in the West after sunset and is the lost in the Sun's glare until the last half of February when it becomes a morning object (mag. 0.7). By late May it rises in the middle of the night, and around August 1 becomes an all-night object at magnitude 0.2. By mid-October, Saturn sets in the middle of the night and is an earl night object.

Full Moon Nights: 01/28, 02/26, 03/28, 04/26, 05/25, 06/24, 07/23, 08/21, 09/20, 10/19&20, 11/18, 12/18. (See notes below.)

2022

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

01/03 - 23:54 MST - Earth closest to the Sun (0.9833365 au)

01/07 04h MST - Mercury at greatest elongation, 19.2° E.

01/14 - Year 2775 Ab Urbe Condita starts (Roman/Julian calendar)

02/01 (Tuesday) - Chinese New Year (year of the Tiger) - see notes

02/16 - 15h MST - Mercury at greatest elongation 26.3° W.

03/13 - MDT in effect

03/20 - 3h MDT - Venus at greatest elongation 46.6° W.

03/20 09:33 MDT - Spring Equinox

04/02 evening - Ramadan

04/15 evening - Passover

04/17 - Easter Sunday

04/24 - Orthodox Easter

04/29 2h MDT - Mercury at greatest elongation 20.6° E.

04/30 - a partial solar eclipse starts at 12:45 MDT and ends at 16:38, but from HVO, and nearby, none of the sun's disk will be obscured. Best observer's position 62.87 S, 69.25 W, magnitude 0.639, 64% obscuration.

05/02 evening - Eid ul-Fitr

05/15 - a Total Lunar Eclipse occurs: first contact of the umbra at 20:28 MDT, totality starts at 21:29 and ends at 22:54 with the Moon outside the umbra at 23:55

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

06/16 - 9h MDT - Mercury at greatest elongation 23.2° W.

06/21 03:14 MDT - Summer Solstice, longest day of the year at HVO: 15h 30m 9s.

06/26&27 - 20:40:38 MDT - Latest sunset at HVO

07/04 1h MDT - Earth farthest from the Sun (1.01672 au)

07/29 evening - Year 1444 Anno Hegira starts (Islamic)

08/14 11h MDT - Saturn at opposition

08/14 16h MDT - Saturn appears closest to Earth (8.8568 au)

08/27 10h MDT - Mercury at greatest elongation 27.3° E.

09/22 19:04 MDT - Fall Equinox

09/25 evening - Year 5783 Anno Mundi starts (Jewish)

09/25 20h MDT - Jupiter appears closest to Earth (3.9526 au)

09/26 14h MDT - Jupiter at opposition

10/04 evening - Yom Kippur

10/08 15h MDT - Mercury at greatest elongation 18.4° W.

10/25 - A partial solar eclipse occurs, but will not be visible from anywhere near here. The best view will be at 05:00 MDT as seen from 62.38° N, 79.77° E., magnitude 0.682, 82% obscured.

11/06 - MST returns

11/08 - A total Lunar Eclipse occurs: as seen at HVO, first contact with the umbra at 02:09 MST, totality from 03:16 to 04:42, and the Moon leaves the umbra at 05:49.

11/30 19h - Mars appears closest to Earth (0.544465 au)

12/07 6h - Mars at opposition

12/09 - 16:14:39 MST - Earliest sunset at HVO

12/18 evening - Hanukkah

12/21 14:48 MST - Winter Solstice - Shortest day of the year at HVO: 8h 52m 36s

Planet Pairings, within 5 degrees. (approx. start date - closest - approx. end date): Mercury and Saturn at dusk (01/09-12-16), Venus and Mars at dawn (3/02-16-27), Venus and Saturn at dawn (3/24-29-4/02), Mars and Saturn (3/28-4/05-4/12), Mars and Jupiter at dawn (5/21-29-6/06), Mercury and Venus (12/23-28-31).

The Moon and a planet: Mercury at dusk 1/03, Mars at dawn 1/29, Jupiter at dusk 2/02, Mars at dawn 2/27, Jupiter at dawn 4/27, Mercury at dusk 5/02, Venus 5/26 at noon and 5/27 at dawn, Jupiter 6/21 at dawn, Mars 6/22 at dawn, Venus 6/26 at dawn, Mercury 6/27 at dawn, Jupiter 7/18 at night, Mars 7/20 at night and 7/21 at dawn, Venus 7/26 at dawn and noon, Saturn 8/11 all night, Jupiter 8/14 rising after dusk then rest of the night, Mars 8/18 rising after dusk then rest of the night, Venus 8/25 during the day, Jupiter 9/11 at dawn, Mars 9/16 at night, Jupiter 10/08 at dusk, 10/14 at night, Mercury 10/24 at dawn, Venus 10/25 daytime -but close also to the Sun, Saturn 11/01 at dusk, Jupiter 11/04 at dusk onward, Mars 11/10 at rising and on into the night, Venus 11/24 at noon, Jupiter 12/01 at dusk onward, Mars 12/07 all night, Mercury 12/24 at dusk.

Mercury: In early January is low, but bright, in the evening sky fading and sinking until it becomes lost in the glare by mid-January. In February it becomes a poor target in the morning sky, then again disappears until mid-April when it becomes a bright, but fading object visible at dusk until May; around May first until mid-May it would be advisable to use binoculars or a telescope. From mid-May Mercury is again lost until mid-June to early-July when it appears low in the sky at dawn. From early August until late August it appears very low in the evening sky. In October Mercury reappears in the sky at dawn growing brighter and higher (best October 6-12) then disappearing again late in the month. Its last apparition is in the evening sky starting about December 9th, and peaking before Christmas.

Venus starts the year as an evening object low on the horizon, sinking lower day by day, and becomes a bright morning object in mid-January, it peaks in mid-February, then becomes lower sinking lowest in May, then climbing to another high point in July and then sinks lower in August until it is lost in mid-September before reappearing in the evening sky in mid-December.

Mars starts the year as a morning object at magnitude -1.5, and slowly becomes a little brighter until in April it starts gaining altitude at dawn and steadily brightening. On the night of December 8-9 Mars is brightest at magnitude -1.9 and is an all-night object.

Jupiter starts the year as an evening object until it sets soon after the Sun by mid-February. Jupiter becomes a morning object in early April. It is best on the night of September 26 at magnitude -2.9 and is then an all-night object. It finishes the year as a bright evening object.

Saturn starts the year as an evening object (magnitude 0.7) until late January. It then reappears as a morning object early in March. By the night of August 14 it is an all-night object at magnitude 0.3, and thereafter becomes an evening object for the rest of the year.

Full Moon Nights: 01/17, 02/15-16, 03/17, 04/16, 05/15, 06/13, 07/13, 08/11, 09/09, 10/09, 11/07, 12/07. (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 materials 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 above on this page 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 was 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 on this page; and 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. An 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.

About daily polynomials for lunar coordinates: The Astronomical Almanac lists the apparent right ascension, apparent declination, and true distance (light time not factored in) of the moon at zero hours Terrestrial Time for each day of the year. The online web site at http://asa.usno.navy.mil/SecD/LunarPoly.html gives daily polynomials for apparent right ascension, apparent declination, and horizontal parallax for any desired time during the day listed. However, there are a few points to consider: (1) the polynomials for 2019 are not yet posted as of April, 2019. (2) The coefficients for horizontal parallax do not have the required number of significant figures to match the distance information listed in the Astronomical Almanac.

Please report corrections and suggestions to g e o r g e 0 7 @ r a p . m i d c o . n e t (using no spaces in the address).