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

June 2017
  • Thursday, 6/1/2017 - Io OcD - Time: 02:00
    • Io disappears behind Jupiter at 0222.
  • Thursday, 6/1/2017 - 1st Qtr - Time: 05:30
    • -
  • Thursday, 6/1/2017 - Dbl Sat/Sh Tr of Jup - Time: 22:00
    • 2218 Eur Tr begins
      2338 Io Tr begins (Dbl Sat Tr begins)
      0031 Eur Sh Tr begins
      0042 Io Sh Tr begins (Dbl Sh Tr begins)
      0046 Eur Tr ends (Dbl Sat Tr ends)
      0149 Io Tr ends
      0252 Io Sh Tr ends (Dbl Sh Tr ends)
      0256 Eur Sh Tr ends
  • Friday, 6/2/2017 - Io EcR - Time: 24:00
    • At 0008 (on 6/3) Io emerges from Jupiter's shadow 0.4 Jupiter diameter east of Jupiter.
  • Saturday, 6/3/2017 - Ven GEW - Time: 06:00
    • Venus is at greatest elongation west in the morning sky.
  • Saturday, 6/3/2017 - Dbl Sh Tr of Jup & Eur EcR - Time: 21:00
    • The shadows of Io and Ganymede are in transit as Jupiter becomes visible in twilight.
      2121 Io Sh Tr ends (Dbl Sh Tr ends)
      2136 Europa reappears from Jupiter's shadow 0.7 Jupiter diameter east of Jupiter
      2138 Gan Sh Tr ends
  • Saturday, 6/3/2017 - Mn Vnr Jup - Time: 22:00
    • -
  • Friday, 6/9/2017 - Dbl Sat Tr of Jup - Time: 00:30
    • 0046 Eur Tr begins
      0128 Io Tr begins (Jupiter's altitude now 13° in WSW)
      Jupiter sets with both transits in progress.
  • Friday, 6/9/2017 - "Strawberry" Moon - Time: 06:00
    • This is the smallest full moon of 2017.
  • Friday, 6/9/2017 - Jup stat - Time: 22:00
    • Jupiter ends retrograde motion.
  • Friday, 6/9/2017 - Mn nr Sat - Time: 22:00
    • -
  • Friday, 6/9/2017 - Io OcD - Time: 22:30
    • Io disappears behind Jupiter at 2240. (It will reappear from Jupiter's shadow 0.5 Jupiter diameter east of Jupiter at 0203, by which time Jupiter is low in the west, as calculated for the RFO site.)
  • Saturday, 6/10/2017 - Io Sat/Sh Tr, Gan Sh Tr & Eur EcR - Time: 21:30
    • The Io transits are in progress as Jupiter becomes visible in twilight.
      2207 Io Tr ends
      2315 Io Sh Tr ends
      2319 Gan Sh Tr begins (north polar region)
      0010 Europa reappears from Jupiter's shadow 0.7 Jupiter diameter east of Jupiter
      0136 Gan Sh Tr ends
  • Tuesday, 6/13/2017 - Occ of pi & rho Cap - Time: 02:30
    • At 0252 the mag 5.1 star pi Capricorni will reappear from behind the moon's dark limb at axis angle 238° (or 58° from the south cusp). At 0410 mag 4.9 rho Cap reappears from behind the dark limb at axis angle 314° (or 46° from the north cusp). Pi Cap is an extremely close double and very close triple. Rho Cap is a very close double. Thus, both events may be non-instantaneous for those with proper equipment. (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)
  • Thursday, 6/15/2017 - Sat opp - Time: 03:00
    • Saturn is at opposition in Ophiuchus, reaching magnitude 0.0, a disk diamter of 18", ring diameter of 42", and ring tilt of 27°. Saturn's rings are now at maximum tilt, which will decrease in coming years.
  • Friday, 6/16/2017 - Nep stat - Time: 16:00
    • Neptune, in Aquarius, begins retrograde motion.
  • Saturday, 6/17/2017 - Io OcD - Time: 00:30
    • Io disappears behind Jupiter at 0032.
  • Saturday, 6/17/2017 - Last Qtr - Time: 04:30
    • -
  • Saturday, 6/17/2017 - Io Sat/Sh Tr, Gan Tr & Eur OcD - Time: 21:30
    • 2147 Io Tr begins (in late civil twilight)
      2153 Eur disappears behind Jupiter
      2216 Gan Tr begins (north polar region) Dbl Tr begins
      2259 Io Sh Tr begins
      2359 Io Tr ends - Dbl Tr ends
      0048 Gan Tr ends
      0110 Io Sh Tr ends
  • Sunday, 6/18/2017 - Io EcR - Time: 22:00
    • At 2227 Io reappears from Jupiter's shadow 0.5 Jupiter diameter east of Jupiter.
  • Tuesday, 6/20/2017 - CrMn nr Ven - Time: 04:00
    • -
  • Tuesday, 6/20/2017 - Summer Solstice - Time: 21:30
    • The summer solstice occurs at 9:24pm.
  • Friday, 6/23/2017 - Lrg Tides thru 6/25 - Time: 00:00
    • Large tides due to new moon occurring 16 hours before perigee.
  • Friday, 6/23/2017 - New Moon - Time: 19:30
    • -
  • Saturday, 6/24/2017 - Io Sat/Sh Tr & Eur OcD - Time: 23:30
    • 2340 Io Tr begins
      0023 Eur disappears behind Jupiter
      0054 Io Sh Tr begins with Jupiter low in WSW
  • Sunday, 6/25/2017 - Io EcR - Time: 24:00
    • Io reappears from Jupiter's shadow 0.5 Jupiter diameter east of Jupiter at 0022 on 6/26.
  • Monday, 6/26/2017 - Eur Sh Tr - Time: 21:30
    • Note: An Io Sh Tr and Eur Tr end within 10 minutes prior to the start of this event, which is during nautical twilight.
      2142 Eur Sh Tr begins
      0006 Eur Sh Tr ends
  • Tuesday, 6/27/2017 - CrMn vnr Regulus - Time: 22:00
    • The crescent moon is very near the very bright blue star Regulus in Leo. Use binoculars to appreciate this colorful sight.
  • Wednesday, 6/28/2017 - Gan Ec - Time: 21:30
    • This event will have several interesting aspects worthy of mention. Observation should start around 9pm, or as early as you can spot Jupiter in the sky (it will be high in the SW). Io is by itself west of Jupiter, and Callisto, Ganymede and Europa form a nice triangle to the east, with Europa furthest east. The tilt of the satellites' orbital plane is evident: Callisto and Io are in front of Jupiter moving west and thus north of Jupiter's equator. Ganymede and Europa are behind Jupiter moving east and well to the south. Ganymede will now pass totally through Jupiter's shadow:
      2130 Gan disappears 0.7 Jupiter diameter east
      2346 Gan reappears 1.3 Jupiter diameter east
  • Friday, 6/30/2017 - 1st Qtr - Time: 17:30
    • -
  • Friday, 6/30/2017 - Mn vnr Jup - Time: 23:00
    • -

July 2017
  • Sunday, 7/2/2017 - Juno opp - Time: 06:00
    • The minor planet Juno is at opposition in Scutum at 10th magnitude. A finder's chart is essential.
  • Sunday, 7/2/2017 - Io OcD - Time: 22:30
    • Io disappears behind Jupiter at 2248.
  • Monday, 7/3/2017 - Io/Eur Sat/Sh Tr - Time: 21:00
    • Io is in transit at sunset. Then,
      2117 Io Sh Tr begins
      2142 Eur Tr begins, near Io's Sh
      - Begin double transit
      2214 Io Tr ends
      - End double transit
      2327 Io Sh Tr ends
      0019 Eur Tr ends
      0019 Eur Sh Tr begins, though by this time Jupiter's altitude is only 8° (at RFO).
  • Wednesday, 7/5/2017 - Gan OcR - Time: 22:30
    • Ganymede reappears from behind Jupiter's southeast polar region at 2245.
  • Thursday, 7/6/2017 - Mn nr Sat - Time: 22:00
    • -
  • Saturday, 7/8/2017 - "Buck" Moon - Time: 21:00
    • -
  • Saturday, 7/8/2017 - Mer in W thru 7/29 - Time: 21:00
    • Mercury provides a poor evening apparition reaching a maximum altitude 45 minutes after sunset (at RFO's latitude) of only 6° on 7/21.
  • Sunday, 7/9/2017 - Plu opp - Time: 21:00
    • Pluto is at opposition at mag 14.2 in Sagittarius. A finder's chart and large aperture is essential for this very challenging target.
  • Monday, 7/10/2017 - Io Sat/Sh Tr - Time: 21:30
    • 2157 Io Tr begins
      2312 Io Sh Tr begins
      0008 Io Tr ends, with Jupiter now only 5° high (at RFO). Jupiter sets with Io's shadow in transit.
  • Tuesday, 7/11/2017 - Io EcR - Time: 22:30
    • At 2242 Io reappears from Jupiter's shadow 0.5 Jupiter diameter east of Jupiter.
  • Wednesday, 7/12/2017 - Eur OcR/Ec - Time: 21:00
    • At 2118 Europa reappears from behind Jupiter's SE limb. Then, very shortly thereafter, at 2121, Europa disappears into Jupiter's shadow VERY close to Jupiter's limb. At 2344 Europa reappears 0.8 Jupiter diameter east of Jupiter, by which time Jupiter's altitude is only 8° (at RFO). Ganymede approaches Jupiter's SW polar limb during these events and is occulted just before Jupiter sets (at RFO).
  • Sunday, 7/16/2017 - Last Qtr - Time: 12:30
    • -
  • Thursday, 7/20/2017 - CrMn vnr Ven - Time: 04:30
    • The crescent moon is very near Venus, with the bright red-orange star Aldebaran and the Pleiades cluster above this pair and slightly south.
  • Sunday, 7/23/2017 - New Moon - Time: 02:30
    • -
  • Wednesday, 7/26/2017 - Io Sat/Sh Tr - Time: 21:30
    • Io is in transit at sunset.
      2130 Io Sh Tr begins
      2230 Io Tr ends
      Jupiter sets with Io's shadow in transit.
  • Friday, 7/28/2017 - Eur Sat/Sh Tr - Time: 21:30
    • Europa is in transit at sunset.
      2130 Eur Sh Tr begins
      2232 Eur Tr ends
      Jupiter sets with Europa's shadow in transit.
  • Friday, 7/28/2017 - Mn nr Jup - Time: 22:00
    • -
  • Sunday, 7/30/2017 - 1st Qtr - Time: 08:30
    • -

August 2017
  • Wednesday, 8/2/2017 - Mn vnr Sat - Time: 23:00
    • -
  • Thursday, 8/3/2017 - Ura stat - Time: 02:00
    • Uranus begins retrograde motion in Pisces.
  • Monday, 8/7/2017 - "Sturgeon" Moon - Time: 11:00
    • -
  • Saturday, 8/12/2017 - Perseids Peak - Time: 12:00
    • This is a very unfavorable year for Perseid meteor viewing with a gibbous moon during morning hours and the peak predicted during daylight hours locally.
  • Monday, 8/14/2017 - Last Qtr - Time: 18:00
    • -
  • Wednesday, 8/16/2017 - CrMn Vnr Aldebaran - Time: 02:30
    • The crescent moon is VERY near the bright red-orange star Aldebaran. Use binoculars to appreciate the colorful star next to the moon.
  • Friday, 8/18/2017 - CrMn nr Ven - Time: 05:00
    • -
  • Saturday, 8/19/2017 - CrMn nr Ven - Time: 05:00
    • -
  • Monday, 8/21/2017 - Solar Eclipse - Time: 09:00
    • An 82% partial solar eclipse occurs from 9:01 to 11:37am with the eclipse maximum at 10:15. These values are calculated for the RFO site (using Occult4) and differ as distance from RFO increases. WARNING: Use approved safe viewing methods to observe the eclipse to avoid eye damage or blindness. A total solar eclipse occurs for those along a path that runs across the U.S. through or very near Salem OR, St. Louis MO, Nashville TN, and Charleston SC.
  • Monday, 8/21/2017 - New Moon - Time: 11:30
    • -
  • Thursday, 8/24/2017 - Cr Mn nr Jup - Time: 20:30
    • -
  • Friday, 8/25/2017 - Sat stat - Time: 08:00
    • Saturn ends retrograde motion in Ophiuchus.
  • Tuesday, 8/29/2017 - 1st Qtr - Time: 01:00
    • -
  • Tuesday, 8/29/2017 - Mn nr Sat - Time: 21:30
    • -

September 2017
  • Monday, 9/4/2017 - Nep opp - Time: 22:00
    • -
  • Wednesday, 9/6/2017 - "Harvest" Moon - Time: 00:30
    • -
  • Tuesday, 9/12/2017 - Last Qtr - Time: 23:30
    • -
  • Tuesday, 9/19/2017 - Ura Opp - Time: 10:00
    • -
  • Tuesday, 9/19/2017 - New Moon - Time: 22:30
    • -
  • Friday, 9/22/2017 - Autumnal Equinox - Time: 13:00
    • The autumnal equinox occurs at 1:02pm.
  • Wednesday, 9/27/2017 - 1st Qtr - Time: 20:00
    • -

October 2017
  • Thursday, 10/5/2017 - "Hunter's" Moon - Time: 11:30
  • Thursday, 10/12/2017 - Last Qtr - Time: 05:30
    • -
  • Thursday, 10/19/2017 - New Moon - Time: 12:00
    • -
  • Saturday, 10/21/2017 - Orionids Peak - Time: 04:00
    • Conditions are very favorable for the Orionid Meteor Shower. Rates of about 20 meteors per hour are expected at the peak and off-peak outbursts are possible.
  • Friday, 10/27/2017 - 1st Qtr - Time: 15:30
    • -

November 2017
  • Friday, 11/3/2017 - "Beaver" Moon - Time: 10:30
  • Sunday, 11/5/2017 - DST Ends - Time: 02:00
    • -
  • Friday, 11/10/2017 - Last Qtr - Time: 12:30
    • -
  • Friday, 11/17/2017 - Leonids Peak - Time: 08:30
    • While moon conditions are very favorable, meteor activity is expected to be low this year with only about 10 per hour at the peak, which is likely in daylight hours locally. But unexpected activity is always possible. Meteors are viewable after midnight until about 0530.
  • Saturday, 11/18/2017 - New Moon - Time: 03:30
    • -
  • Sunday, 11/26/2017 - 1st Qtr - Time: 09:00
    • -

December 2017
  • Sunday, 12/3/2017 - "Cold" Moon - Time: 08:00
    • -
  • Saturday, 12/9/2017 - Last Qtr - Time: 24:00
    • -
  • Wednesday, 12/13/2017 - Geminids Peak - Time: 22:30
    • Conditions are highly favorable for this strong meteor shower with rates of about 120 meteors per hour lasting for a long time around the peak. The meteors are viewable all night. The crescent moon rises at about 4am on 12/14, interfering somewhat.
  • Sunday, 12/17/2017 - New Moon - Time: 22:30
    • -
  • Thursday, 12/21/2017 - Winter Solstice - Time: 08:30
    • The winter solstice occurs at 8:28am.
  • Friday, 12/22/2017 - Ursids Peak - Time: 07:00
    • Conditions are very favorable for this modest meteor shower with about 10 per hour at peak, though there have been rare outbursts of up to 50. The meteors are viewable all night until after twilight starts around 6am.
  • Tuesday, 12/26/2017 - 1st Qtr - Time: 01:30
    • -

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