RFO

What's Up in the Night Sky

Here's a month-by-month listing of astronomical predictions for the year, compiled by
Jack Welch, RFO astronomy instructor.

 

Abbreviations

Astr Twi/AT -Astronomical Twilight
Cal - Callisto
Civ Twi/CT - Civil Twilight
Cr - Crescent
Disap - Disappear
Dbl Tr - Double Tansit
E - End/Exit
Ec/Ecl - Eclipse
EcD - Eclipse disappearance
EcR - Eclipse reappearance
Eur - Europa
Ex - Exit
Gan - Ganymede
Gr El - Greatest Elongation
Jup - Jupiter
Lun - Lunar
Max - Maximum
Mer - Mercury
Min - Minimum
Mn - Moon
Naut Twi/NT - Nautical Twilight
Nr - Near
Occ - Occultation
OcD - Occultation disappearance
OcR - Occultation reapparance
Opp - Opposition
Pen - Penumbral
Reap - Reappear
Qtr - Quarter
Sat - Saturn /Satellite
Sh - Shadow
S/St - Start
Stat - Stationary
Tot - Total
Tr - Transit
V Nr - Very Near
Ven - Venus
Zod Lt - Zodiacal Light

 

Observing

Upcoming Observing Highlights

July 2020
  • Thursday, 7/2/2020 - Gan Sh/Sat Tr - Time: 22:00
    • Ganymede and its shadow are in transit when Jupiter rises. By 2200 (RFO region) Jupiter will be 7° high in the ESE. The shadow transit ends at 2251 and Ganymede's transit ends at 2400.
  • Saturday, 7/4/2020 - "Buck" Moon - Time: 21:30
    • -
  • Monday, 7/6/2020 - Io EcD/OcR - Time: 01:00
    • At 0119 Io disappears into Jupiter's shadow 0.1 Jupiter diameter west of Jupiter. It reappears from behind Jupiter at 0348.
  • Monday, 7/6/2020 - Eur Sh/Sat Tr - Time: 03:30
    • Europa's shadow begins transiting Jupiter at 0352 followed by Europa itself at 0415 (during astro twilight). The transits are in progress at sunrise.
  • Monday, 7/6/2020 - Io Sh/Sat Tr - Time: 22:30
    • Io's shadow transits Jupiter from 2236 to 0053, followed by Io from 2247 to 0104. Note that Io follows its shadow by about 0.1 Jupiter diameter.
  • Tuesday, 7/7/2020 - Io OcR - Time: 22:00
    • Io emerges from behind Jupiter's east limb at 2214.
  • Tuesday, 7/7/2020 - Eur EcD/OcR - Time: 22:30
    • Europa disappears into Jupiter's shadow at 2243 and emerges from behind Jupiter's east limb at 0151.
  • Wednesday, 7/8/2020 - Cal Sh/Sat Tr - Time: 23:30
    • Calisto's shadow transits Jupiter from 2333 to 0334, followed by Callisto from 0041 to 0448 (ending in nautical twilight). Note that Callisto follows its shadow by about 0.3 Jupiter diameter.
  • Thursday, 7/9/2020 - Gan Sh/Sat Tr - Time: 23:30
    • Ganymede's shadow transits Jupiter from 2331 to 0251, followed by Ganymede from 2355 to 0316. Note that Ganymede follows its shadow by about 0.15 Jupiter diameter.
  • Sunday, 7/12/2020 - Last Qtr - Time: 16:30
    • -
  • Monday, 7/13/2020 - Io EcD - Time: 03:00
    • At 0313 Io disappears into Jupiter's shadow VERY near Jupiter's west limb since Jupiter is almost at opposition. Use high magnification to see if you can detect the thin shadow separation between the two objects.
  • Monday, 7/13/2020 - Jup opp - Time: 24:00
    • Jupiter is at opposition in Sagittarius reaching magnitude -2.8 and a disk diameter of 47.6".
  • Tuesday, 7/14/2020 - Io Sat/Sh Tr - Time: 00:30
    • Occurring minutes after opposition, it will be very difficult to detect the small bit of Io's shadow that might be visible on the east edge of Io. Use high magnification. Both the satellite and shadow transits begin at 0031 and end at 0248.
  • Tuesday, 7/14/2020 - Io OcD/EcR - Time: 21:30
    • Io disappears behind Jupiter at 2141 and emerges from Jupiter's shadow VERY near the east limb. Use high magnification to detect the shadow separation between these two objects.
  • Wednesday, 7/15/2020 - Eur OcD/EcR - Time: 01:00
    • Europa disappears behind Jupiter at 0116 and emerges from Jupiter's shadow VERY near Jupiter's east limb at 0410 (during astro twilight).
  • Wednesday, 7/15/2020 - Pluto opp - Time: 12:00
    • The dwarf planet Pluto is at opposition in Sagittarius at magnitude 14.4. A finder's chart is essential for spotting this difficult target.
  • Thursday, 7/16/2020 - CrMn nr Ven & Aldebaran - Time: 05:00
    • The crescent moon is above the pair of Venus and the bright red-orange star Aldebaran. Use binoculars.
  • Thursday, 7/16/2020 - Eur Sat/Sh Tr - Time: 21:00
    • Europa and its shadow are in transit when Jupiter rises. At 2100 Jupiter will be about 7° high in the ESE (RFO region) with the shadow transit about half-way across Jupiter and Europa extremely close behind its shadow. The transit ends at 2222 and the shadow transit ends at 2231.
  • Friday, 7/17/2020 - Eur Sat/Sh Tr - Time: 03:00
    • Europa transits Jupiter beginning at 0311 followed by its shadow at 0330. Note that the shadow transits about 0.2 Jupiter diameter behind Europa. The transits are in progress at sunrise.
  • Friday, 7/17/2020 - CrMn nr Ven & Aldebaran - Time: 05:00
    • The crescent moon is near Venus and the bright red-orange star Aldebaran. Use binoculars.
  • Friday, 7/17/2020 - Mer in E thru 8/3 - Time: 05:00
    • Mercury has a moderately good morning apparition in the ENE with a maximum altitude 45 minutes before sunrise of 7° on 7/26. Greatest elongation west is on 7/22. Mercury is dim in the first few days then brightens.
  • Saturday, 7/18/2020 - CrMn nr Mer - Time: 05:00
    • Look for the crescent moon above Mercury 45 minutes before sunrise (or at 0516 calculated for the RFO site). Note that Mercury will be quite dim and about 5° high 21° north of due east.
  • Sunday, 7/19/2020 - 1.8% CrMn nr Mer - Time: 05:00
    • An ultra-thin 1.8% crescent moon will be slightly north of Mercury. Look 45 minutes before sunrise (or at 0517 calculated for the RFO site) and use binoculars. Mercury will be dim and about 6° high 21° north of due east.
  • Monday, 7/20/2020 - New Moon - Time: 10:30
    • -
  • Monday, 7/20/2020 - Sat opp - Time: 15:00
    • Saturn is at opposition in Sagittarius reaching magnitude 0.1 and a disk diameter of 18.5". The rings diameter is 42" with a tilt angle of 21.9°.
  • Tuesday, 7/21/2020 - Io Sat/Sh Tr - Time: 02:00
    • Io transits Jupiter from 0215 to 0432, followed by its shadow from 0225 to 0443. Note that the shadow follows Io by about 0.1 Jupiter diameter and the transits end during astro twilight.
  • Tuesday, 7/21/2020 - 2.7% CrMn - Time: 21:00
    • An ultra-thin 2.7% crescent moon is 7° high 18° north of due west 30 minutes after sunset (or at 2059 calculated for the RFO site). Use binoculars.
  • Tuesday, 7/21/2020 - Io OcD/EcR - Time: 23:00
    • Io disappears behind Jupiter at 2324 and emerges from Jupiter's shadow 0.1 Jupiter diameter east of Jupiter at 0153.
  • Wednesday, 7/22/2020 - Eur OcD - Time: 03:30
    • Europa disappears behind Jupiter at 0332.
  • Wednesday, 7/22/2020 - Io Sh/Sat Tr - Time: 20:30
    • Io's transit is in progress at sunset and ends at 2258. Io's shadow transit begins at 2054 (late civil twilight) and ends at 2312. Note that the shadow follows Io by about 0.15 Jupiter diameter.
  • Thursday, 7/23/2020 - Eur Sat/Sh Tr - Time: 21:30
    • Europa transits Jupiter from 2149 to 0036, followed by its shadow from 2218 to 0105. Note that the shadow follows Europa by about 0.2 Jupiter diameter.
  • Saturday, 7/25/2020 - Cal Sh Tr - Time: 21:00
    • Calisto's shadow is in transit of Jupiter at sunset and ends at 2145 during astro twilight.
  • Monday, 7/27/2020 - 1st Qtr - Time: 05:30
    • -
  • Tuesday, 7/28/2020 - Gan EcR - Time: 00:30
    • At 0057 Ganymede emerges from Jupiter's shadow about 0.3 Jupiter diameter east of Jupiter.
  • Tuesday, 7/28/2020 - Io Sat/Sh Tr - Time: 03:30
    • Io begins transiting Jupiter at 0359 followed by its shadow at 0420 (just before the start of astro twilight). The shadow follows Io by about 0.2 Jupiter diameter and the transits are in progress at sunrise.
  • Wednesday, 7/29/2020 - Io OcD/EcR - Time: 01:00
    • Io disappears behind Jupiter at 0108 and emerges from Jupiter's shadow about 0.15 Jupiter diameter east of Jupiter at 0347.
  • Wednesday, 7/29/2020 - Io Sat/Sh Tr - Time: 22:00
    • Io transits Jupiter from 2225 to 0043, followed by its shadow from 2249 to 0106. Note that the shadow follows Io by about 0.2 Jupiter diameter.
  • Thursday, 7/30/2020 - Io EcR - Time: 22:00
    • Io emerges from Jupiter's shadow about 0.15 Jupiter diameter east of Jupiter at 2216.
  • Thursday, 7/30/2020 - Eur Sat/Sh Tr - Time: 24:00
    • Europa transits Jupiter from 0003 to 0250 (a.m. of 7/31), followed by its shadow from 0053 to 0341. Note that the shadow follows Europa by about 0.3 Jupiter diameter.

August 2020
  • Saturday, 8/1/2020 - Mer in E thru 8/3 - Time: 05:30
    • Mercury ends a moderately good morning apparition in the ENE during the first few days of August. Look for it low in the ENE around 45 minutes before sunrise.
  • Saturday, 8/1/2020 - Mn vnr Jup & Sat - Time: 21:30
    • -
  • Saturday, 8/1/2020 - Eur EcR - Time: 22:30
    • Europa emerges from Jupiter's shadow 0.3 Jupiter diameter east of Jupiter at 2244.
  • Sunday, 8/2/2020 - Mn nr Jup & Sat - Time: 21:30
    • -
  • Sunday, 8/2/2020 - Cal OcD - Time: 23:30
    • Callisto disappears behind Jupiter at 2350.
  • Monday, 8/3/2020 - Cal OcR - Time: 03:30
    • Callisto appears from behind Jupiter's ESE limb at 0356.
  • Monday, 8/3/2020 - "Sturgeon" Moon - Time: 09:00
    • -
  • Monday, 8/3/2020 - Gan OcD - Time: 23:30
    • Ganymede disappears behind Jupiter at 2331.
  • Wednesday, 8/5/2020 - Io OcD - Time: 02:30
    • Io disappears behind Jupiter at 0253.
  • Wednesday, 8/5/2020 - Io Sat/Sh Tr - Time: 24:00
    • Io transits Jupiter from 0011 to 0228 (a.m. of 8/6) followed by its shadow from 0044 to 0301.
  • Thursday, 8/6/2020 - Io OcD/EcR - Time: 21:00
    • Io disappears behind Jupiter at 2119 (late nautical twilight) then emerges from Jupiter's shadow about 0.25 Jupiter diameter east of Jupiter at 0010.
  • Friday, 8/7/2020 - Eur Sat/Sh Tr - Time: 02:00
    • Europa begins transiting Jupiter at 0219. It's shadow begins transiting at 0328, by which time Jupiter will be 8° in the SW (in RFO region). Both transits are in progress when Jupiter sets.
  • Friday, 8/7/2020 - Occ of 30 Psc - Time: 03:00
    • At 0334 the mag 3.5 star 30 Piscium (and extremely close double) will reappear from behind the moon's dark limb at axis angle 277° (or 89° from the north cusp). (Calculated using Occult4 for the RFO site. Observers must calculate the details for their own site to reliably capture a reappearance. Details differ as distance from RFO increases.)
  • Friday, 8/7/2020 - Occ of 33 Psc - Time: 05:30
    • At 0530 the mag 4.1 star 33 Piscium (and extremely close double) will reappear from behind the moon's dark limb at axis angle 216° (or 30° from the south cusp). (Calculated using Occult4 for the RFO site. Observers must calculate the details for their own site to reliably capture a reappearance. Details differ as distance from RFO increases.)
  • Friday, 8/7/2020 - Io Sat/Sh Tr - Time: 20:30
    • Both transits are in progress at sunset. Io's transit of Jupiter ends at 2054 (in nautical twilight) and the its shadow transit ends at 2130 (astro twilight).
  • Saturday, 8/8/2020 - Eur OcD - Time: 21:00
    • Europa disappears behind Jupiter at 2115 (end of nautical twilight).
  • Sunday, 8/9/2020 - Eur EcR - Time: 01:00
    • Europa emerges from Jupiter's shadow 0.4 Jupiter diameter east of Jupiter at 0121.
  • Sunday, 8/9/2020 - Mn vnr Mars - Time: 01:00
    • -
  • Tuesday, 8/11/2020 - Gan OcD - Time: 02:30
    • Ganymede disappears behind Jupiter at 0253, at which time Jupiter will be 10° in the SW (in RFO region).
  • Tuesday, 8/11/2020 - Last Qtr - Time: 09:30
    • -
  • Wednesday, 8/12/2020 - Perseid sub-peak? - Time: 03:00
    • There might be a "filament stream" sub-peak outburst in the Perseid meteor shower around 3am, though this is uncertain.
  • Wednesday, 8/12/2020 - Perseids peak - Time: 06:00
    • The Perseid meteor shower peak is predicted to occur between about 6am and 10am. Begin observing around 2130 on 8/11. Moonlight interferes after 0030 on 8/12, unfortunately. Try to block the moon glare from your view. Twilight starts around 5am. The Perseids are active for many days and observing conditions are more favorable in subsequent mornings after the peak.
  • Thursday, 8/13/2020 - Io Sat/Sh Tr - Time: 01:30
    • Io transits Jupiter starting at 0157 followed by its shadow starting at 0239, at which time Jupiter will be 11° high in the SW (RFO region). Both transits are in progress when Jupiter sets.
  • Thursday, 8/13/2020 - Io OcD - Time: 23:00
    • Io disappears behind Jupiter at 2305.
  • Friday, 8/14/2020 - Io EcR - Time: 02:00
    • Io emerges from Jupiter's shadow 0.3 Jupiter diameter east of Jupiter at 0205.
  • Friday, 8/14/2020 - Dbl Sh Tr of Jup - Time: 20:30
    • Ganymede's shadow and Io are in transit at sunset. Then:
      2018 - Io's Sh Tr begins - Start of Dbl Sh Tr
      Around 2200: Io is directly south of Gan Sh
      2240 - Io Tr ends
      2254 - Gan Sh Tr ends - End of Dbl Sh Tr
      2325 - Io Sh Tr ends
  • Saturday, 8/15/2020 - CrMn nr Ven - Time: 05:00
    • -
  • Saturday, 8/15/2020 - Ura stat - Time: 10:00
    • Uranus, in Aries, begins retrograde motion.
  • Saturday, 8/15/2020 - Io EcR - Time: 20:30
    • Io emerges from Jupiter's shadow 0.3 Jupiter diameter east of Jupiter at 2034 (early nautical twilight).
  • Saturday, 8/15/2020 - Eur OcD - Time: 23:30
    • Europa disappears behind Jupiter at 2334.
  • Monday, 8/17/2020 - 3.4% CrMn nr M44 - Time: 05:30
    • The thin crescent moon is near the bright, large open star cluster Praesepe (M44) in the ENE. Use binoculars.
  • Monday, 8/17/2020 - Eur Sat/Sh Tr - Time: 20:30
    • Both transits are in progress at sunset. Europa's transit ends at 2033 (early nautical twilight), at which time the shadow transit is at about 40%. The shadow transit ends at 2209.
  • Tuesday, 8/18/2020 - New Moon - Time: 19:30
    • -
  • Wednesday, 8/19/2020 - 1.7% CrMn - Time: 20:30
    • Look for an ultra-thin 1.7% crescent moon 4° high 11° north of due west 30 minutes after sunset (or at 2028 calculated for the RFO site). Use binoculars.
  • Wednesday, 8/19/2020 - Cal EcD - Time: 22:00
    • Callisto disappears into Jupiter's shadow about 0.7 Jupiter diameter east of Jupiter at 2231, but start viewing around 2200. Callisto will emerge from the shadow about 1.6 diameter east at 0247 but Jupiter will only be 5° high at that time in the RFO area.
  • Thursday, 8/20/2020 - 6% CrMn - Time: 20:30
    • -
  • Friday, 8/21/2020 - Io OcD - Time: 00:30
    • Io disappears behind Jupiter at 0051.
  • Friday, 8/21/2020 - Dbl Sat/Sh Tr of Jup - Time: 20:30
    • Ganymede is in transit from around sunset. It is half-way across Jupiter at about 2140. Then:
      2211 - Io Tr begins - Start Dbl Satellite Tr
      2303 - Io Sh Tr begins
      2319 - Gan Tr ends - End Dbl Satellite Tr
      2332 - Gan Sh Tr begins - Start Dbl Sh Tr
      0027 - Io Tr ends
      0120 - Io Sh Tr ends - End Dbl Sh Tr
      (Gan Sh Tr ends at 0255, just before Jupiter sets.)
  • Saturday, 8/22/2020 - Io EcR - Time: 22:00
    • Io emerges from Jupiter's shadow 0.4 Jupiter diameter east of Jupiter at 2229.
  • Sunday, 8/23/2020 - Eur OcD - Time: 01:30
    • Europa disappears behind Jupiter at 0156.
  • Monday, 8/24/2020 - Eur Sat/Sh Tr - Time: 20:30
    • Europa's transit of Jupiter is at about 15% at 2030 and ends at 2253. It is followed by its shadow from 2156 (Europa transit then about 65%) to 0045.
  • Tuesday, 8/25/2020 - 1st Qtr - Time: 11:00
    • -
  • Thursday, 8/27/2020 - Cal Tr - Time: 20:30
    • Callisto transits Jupiter from 2036 to 0039.
  • Friday, 8/28/2020 - Ceres opp - Time: 05:00
    • The dwarf planet Ceres is at opposition in Aquarius at magnitude 7.7. It is near the star 86 Aqr. Coordinates at opposition are RA22h58.8m/Dec-23°17.4'. Use a star chart for accurate identification.
  • Friday, 8/28/2020 - Mn Vnr Jup & nr Sat - Time: 21:00
    • -
  • Friday, 8/28/2020 - Dbl Sat Tr & Io Sh Tr - Time: 23:30
    • Ganymede begins transit of Jupiter at 2331. Io begins transit at 2359 (start of double satellite transit). Io's shadow transit starts at 0058, at which time the two satellites are at about 40% transit. Io's transit ends at 0215 when Jupiter will be very low in the SW (RFO region) and its shadow at about 55% transit.
  • Saturday, 8/29/2020 - Io OcD/EcR - Time: 21:00
    • Io disappears behind Jupiter at 2106 (in astro twilight) and emerges from Jupiter's shadow 0.4 Jupiter diameter east of Jupiter at 0024.
  • Saturday, 8/29/2020 - Mn nr Sat & Jup - Time: 21:00
    • -
  • Sunday, 8/30/2020 - Io Sat/Sh Tr - Time: 20:00
    • Both transits are in progress at sunset. Io's transit ends at 2043, at which time the shadow transit is about 50%. The shadow transit ends at 2144.
  • Monday, 8/31/2020 - Eur Sat/Sh Tr - Time: 22:00
    • Europa begins transiting Jupiter at 2229 and its shadow transit begins at 0032. The transit ends at 0116 by which time Jupiter is rather low in the SW (RFO region) and the shadow transit is at about 25%. Jupiter sets with the shadow transit in progress.

September 2020
  • Tuesday, 9/1/2020 - "Harvest" Moon - Time: 22:30
    • -
  • Thursday, 9/10/2020 - Last Qtr - Time: 02:30
    • -
  • Thursday, 9/17/2020 - New Moon - Time: 04:00
    • -
  • Tuesday, 9/22/2020 - Autumnal Equinox - Time: 06:30
    • The equinox occurs at 6:31am.
  • Wednesday, 9/23/2020 - 1st Qtr - Time: 19:00
    • -

October 2020
  • Thursday, 10/1/2020 - "Hunter's" Moon - Time: 14:00
    • -
  • Friday, 10/9/2020 - Last Qtr - Time: 17:30
    • -
  • Friday, 10/16/2020 - New Moon - Time: 12:30
    • -
  • Friday, 10/23/2020 - 1st Qtr - Time: 06:30
    • -
  • Saturday, 10/31/2020 - "Blue" Moon - Time: 08:00
    • -

November 2020
  • Sunday, 11/8/2020 - Last Qtr - Time: 05:30
    • -
  • Saturday, 11/14/2020 - New Moon - Time: 21:00
    • -
  • Saturday, 11/21/2020 - 1st Qtr - Time: 20:30
    • -
  • Monday, 11/30/2020 - "Beaver" Moon - Time: 01:30
    • -

December 2020
  • Monday, 12/7/2020 - Last Qtr - Time: 16:30
    • -
  • Monday, 12/14/2020 - New Moon - Time: 08:30
    • -
  • Monday, 12/21/2020 - Winter Solstice - Time: 02:00
    • The solstice occurs at 2:02am.
  • Monday, 12/21/2020 - 1st Qtr - Time: 15:30
    • -
  • Tuesday, 12/29/2020 - "Cold" Moon - Time: 19:30
    • -

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