Star Almanack
Alexander Ferrari Miller

ISO 2025-W21

Week begins: Monday, May 19, 2025

Notation:

Calendar

DateZodiac dayEvents
Mon, May 19, 2025♉ 31
C98 / NGC 4609 — Telescope 7 — Southern Spring
M60 — Telescope 9 — Tropical Spring
Finest NGC 65 / NGC 4656 · Hockey Stick or Crowbar — Telescope 10 — Northern Spring
Tue, May 20, 2025♊ 1
♊ Sun enters Gemini — 18:54:38 UTC
🌗 Last Quarter — 11:58:46 UTC
β Mus — Naked eye 3 — Antarctic Spring
Mimosa (β Cru) — Naked eye 1 — Southern Spring
C52 / NGC 4697 — Telescope 9 — Tropical Spring
Finest NGC 83 / NGC 4699 · MCG -1-33-13 — Telescope 10 — Tropical Spring
Wed, May 21, 2025♊ 2
Finest NGC 73 / NGC 4725 · MCG 4-30-22 — Telescope 10 — Northern Spring
M94 — Telescope 8 — Northern Spring
Finest NGC 84 / NGC 4762 · MCG 2-33-33 — Telescope 11 — Tropical Spring
C99 / Coalsack · Coalsack Nebula — Telescope — Southern Spring
C94 / NGC 4755 · Jewel Box Cluster — Telescope 4 — Southern Spring
Alioth (ε UMa) — Naked eye 2 — Northern Spring
Thu, May 22, 2025♊ 3
α1 CVn — Binoculars 6 — Northern Spring
Cor Caroli (α2 CVn) — Naked eye 3 — Northern Spring
M64 — Telescope 9 — Tropical Spring
Fri, May 23, 2025♊ 4
C105 / NGC 4833 — Telescope 7 — Antarctic Spring
C35 / NGC 4889 — Telescope 11 — Northern Spring
Sat, May 24, 2025♊ 5
C83 / NGC 4945 — Telescope 10 — Southern Spring
Sun, May 25, 2025♊ 6
α Com — Binoculars 5 — Tropical Spring

Weekly Solar-System Ephemeris

Snapshot: Week begins May 19, 2025, 00:00 UTC.

(-90° to +90°; defaults +45°, 21:00 LAT)

Notation:
Body☉︎☽︎☿︎♀︎♂︎♃︎♄︎
Ecliptic♉︎ 28°17′
β −0°00′		♒︎ 9°56′
β −3°36′		♉︎ 15°28′
β −1°20′		♈︎ 13°07′
β −1°12′		♌︎ 14°18′
β +1°40′		♊︎ 25°08′
β −0°12′		♓︎ 29°31′
β −2°03′
ObservingNightNaked eye -10.7☉︎Naked eye -4.5Naked eye 1.2Naked eye -1.9Naked eye 1.1
Rise04:3100:3804:0402:4710:0406:1002:23
Set19:2909:4118:1615:2500:4621:4014:12

Extended targets:

Body⚳︎♅︎♆︎♇︎
Ecliptic♈︎ 0°43′
β −9°14′		♉︎ 27°21′
β −0°13′		♈︎ 1°36′
β −1°17′		♒︎ 3°46′
β −3°36′
ObservingTelescope 9.3☉︎Telescope 7.8TelescopeTelescope 14.5
Rise03:0404:3102:2300:20
Set14:0319:2214:2409:08

β = ecliptic latitude (+ north, − south).
Rise and set are Local Apparent Time for the selected latitude.
Naked-eye observing uses the Sun’s altitude at the selected Monday observer time: Daylight (Sun ≥ −0.833°), Civil twilight (−0.833° to −6°), Nautical twilight (−6° to −12°), Astronomical twilight (−12° to −18°), and Night (below −18°).
Solar Glare identifies a body too close to the Sun when the sky-state rule does not already supersede its naked-eye classification.
The Sun’s observing status uses this same five-state sky classification.

Notation:

Planet Finder

Planet Finder — Greek / Symbols
Greek / Symbols
Planet Finder — English
English
Planet Finder — Mixed Learner
Mixed Learner

Sky Notes

Kilroy: Sky Notes · generated 2026-10-23 09:44:05 UTC

View:

ISO 2025-W21 runs from May 19 through May 25. Ceres and Neptune are separated by about 0.9° in geocentric ecliptic longitude at the Monday 00:00 UTC snapshot. Ceres and Saturn are separated by about 1.2° in geocentric ecliptic longitude at the Monday 00:00 UTC snapshot.

Naked eye: 🌗 Last Quarter — 11:58:46 UTC. Moderate moonlight makes timing and local sky position important for faint targets. Use β Mus, Mimosa, Alioth, Cor Caroli as the week’s fixed-sky framework.

Beta Mus: A Distant Beacon in the Southern Sky — Discover the characteristics and significance of Beta Mus, a notable star in the constellation Mus.

Mimosa: A Bright Beacon in the Southern Cross — An overview of the prominent star known as Mimosa, a key feature of the constellation Centaurus and part of the iconic Southern Cross asterism.

Alioth: The Bright Star of the Big Dipper's Handle — A closer look at Alioth, a luminous star that anchors the famous asterism and guides celestial navigation.

Cor Caroli: The Bright Heart of Canes Venatici — A luminous guide star nestled within the constellation Canes Venatici, enchanting stargazers with its distinctive brilliance.

Planets: Moon: Naked eye; magnitude -10.7; direct motion; 65.8% illuminated. Below the horizon at 21:00 local apparent solar time, 45°N. Monday 00:00 UTC snapshot. Conjunction with Venus in ecliptic longitude May 23 21:12 UTC. Conjunction with Ceres in ecliptic longitude May 22 19:37 UTC. Conjunction with Saturn in ecliptic longitude May 22 16:06 UTC. Conjunction with Neptune in ecliptic longitude May 22 19:15 UTC. Mercury: In solar glare; magnitude -1.1; direct motion; 88.2% illuminated. Monday 00:00 UTC snapshot. Conjunction with Uranus in ecliptic longitude May 24 23:15 UTC. Venus: Naked eye; magnitude -4.5; direct motion; 41.9% illuminated. Below the horizon at 21:00 local apparent solar time, 45°N. Monday 00:00 UTC snapshot. Conjunction with Moon in ecliptic longitude May 23 21:12 UTC. Mars: Naked eye; magnitude 1.2; direct motion; 90.3% illuminated. Monday 00:00 UTC snapshot. Ceres: Telescope; magnitude 9.3; direct motion; 97.9% illuminated. Below the horizon at 21:00 local apparent solar time, 45°N. Monday 00:00 UTC snapshot. Conjunction with Moon in ecliptic longitude May 22 19:37 UTC. Conjunction with Neptune in ecliptic longitude May 22 00:37 UTC. Jupiter: Naked eye; magnitude -1.9; direct motion; 99.8% illuminated. Monday 00:00 UTC snapshot. Saturn: Naked eye; magnitude 1.1; direct motion; 99.8% illuminated. Below the horizon at 21:00 local apparent solar time, 45°N. Monday 00:00 UTC snapshot. Conjunction with Moon in ecliptic longitude May 22 16:06 UTC. Uranus: In solar glare; magnitude 5.8; direct motion; 100.0% illuminated. Monday 00:00 UTC snapshot. Conjunction with Mercury in ecliptic longitude May 24 23:15 UTC. Neptune: Telescope; magnitude 7.8; direct motion; 100.0% illuminated. Below the horizon at 21:00 local apparent solar time, 45°N. Monday 00:00 UTC snapshot. Conjunction with Moon in ecliptic longitude May 22 19:15 UTC. Conjunction with Ceres in ecliptic longitude May 22 00:37 UTC. Pluto: Substantial telescope; magnitude 14.5; retrograde motion; 100.0% illuminated. Below the horizon at 21:00 local apparent solar time, 45°N. Monday 00:00 UTC snapshot.

Binoculars: Trace Canes Venatici’s charted figure in the finder, then identify Alpha1 CVn at its charted position. Trace Coma Berenices’s charted figure in the finder, then identify Diadem at its charted position.

Alpha1 CVn: A Bright Beacon in the Constellation of Canes Venatici — An exploration of the star's characteristics and its place in the night sky.

Alpha Comae Berenices: The Bright Diadem of the Coma Berenices Constellation — An enduring beacon in the night sky, Alpha Comae Berenices captivates observers with its significance and luminous presence.

Small telescope: NGC 4609: consult its dedicated finder and observing story for equipment guidance; M60: consult its dedicated finder and observing story for equipment guidance; Hockey Stick or Crowbar: consult its dedicated finder and observing story for equipment guidance; NGC 4697: consult its dedicated finder and observing story for equipment guidance; MCG -1-33-13: consult its dedicated finder and observing story for equipment guidance; MCG 4-30-22: consult its dedicated finder and observing story for equipment guidance; M94: consult its dedicated finder and observing story for equipment guidance; MCG 2-33-33: consult its dedicated finder and observing story for equipment guidance; Jewel Box Cluster: consult its dedicated finder and observing story for equipment guidance; Black Eye Galaxy: consult its dedicated finder and observing story for equipment guidance; NGC 4833: consult its dedicated finder and observing story for equipment guidance; NGC 4889: consult its dedicated finder and observing story for equipment guidance; NGC 4945: consult its dedicated finder and observing story for equipment guidance

Exploring the Open Cluster in the Constellation Crux — A comprehensive look at one of the fascinating stellar groupings within the southern skies.

M60: A Giant Elliptical Galaxy in Virgo — Discover the grandeur of M60, a prominent elliptical galaxy that showcases the majesty of the Virgo constellation.

Hockey Stick in CVn: A Fascinating Galaxy Candidate — Exploring the intriguing possibilities of a mysterious galaxy known as the 'Hockey Stick' in Canes Venatici.

Unveiling the Mysteries of the Virgo E4G Galaxy Group — A detailed exploration of a notable yet less understood fixed astronomical object within the Virgo constellation.

Unveiling MCG -1-33-13: A Galaxy in the Constellation Virgo — Exploring the characteristics and significance of a distant galaxy that enriches our understanding of the universe.

MCG 4-30-22: A Distant Galaxy in the Constellation Com — An overview of MCG 4-30-22, its celestial context, and its significance within the galaxy catalog.

M94: A Spiral Galaxy in Canes Venatici — Discover the structure and significance of one of the prominent galaxies in the constellation Canes Venatici.

Unveiling MCG 2-33-33: A Galaxy in the Constellation Virgo — An overview of the galaxy cataloged as MCG 2-33-33, highlighting its celestial context and scientific interest.

The Jewel Box Cluster: A Stellar Ornament in Crux — An enduring open cluster celebrated for its striking beauty and rich stellar population.

The Black Eye Galaxy: A Cosmic Mystery in the Constellation Coma Bleiades — An Overview of Messier 64, its striking appearance, and its place in the universe.

The Globular Cluster in Mus: A Celestial Treasure — Discover the timeless beauty of this ancient stellar gathering in the constellation Mus.

Exploring Caldwell C-35: A Deep-Sky Wonder in Hercules — An overview of Caldwell C-35, a fascinating deep-sky object located in the Hercules constellation, highlighting its features and scientific significance.

Exploring the Southern Spiral Beauty: A Glimpse into Caldwell 83 — An overview of the intriguing galaxy situated in the Centaurus constellation, known for its detailed structure and role in cosmic studies.

Substantial telescope: No fixed-sky Calendar object is classified as requiring a substantial telescope this week.

Other objects listed this week: None

Mercury

Mercury: in solar glare at the Monday 00:00 UTC snapshot. Rises 04:04; sets 18:16 (45°N, local apparent solar time). Visual magnitude -1.1. The disk is 88.2% illuminated (gibbous). It is 12.9° from the Sun, on its west side. Motion is direct at 1.961° per day in ecliptic longitude at the snapshot. Position reference: Menkar, 11.3° away. Conjunction with Uranus in ecliptic longitude May 24 23:15 UTC. Mercury: 11.3° from Menkar in the Pathfinder.

Venus

Venus: naked eye at the Monday 00:00 UTC snapshot. At 45°N and 21:00 local apparent solar time, it is 41.0° below the horizon. Rises 02:47; sets 15:25 (45°N, local apparent solar time). Visual magnitude -4.5. The disk is 41.9% illuminated (crescent). It is 45.2° from the Sun, on its west side. Motion is direct at 0.847° per day in ecliptic longitude at the snapshot. Position reference: Alrescha, 18.3° away. Conjunction with Moon in ecliptic longitude May 23 21:12 UTC. Venus: 18.3° from Alrescha in the Pathfinder.

Moon

Moon: naked eye at the Monday 00:00 UTC snapshot. At 45°N and 21:00 local apparent solar time, it is 37.6° below the horizon. Rises 00:38; sets 09:41 (45°N, local apparent solar time). Visual magnitude -10.7. The disk is 65.8% illuminated (waning gibbous). It is 108.3° from the Sun, on its west side. Motion is direct at 12.975° per day in ecliptic longitude at the snapshot. Position reference: Dabih, 9.9° away. Conjunction with Venus in ecliptic longitude May 23 21:12 UTC. Conjunction with Ceres in ecliptic longitude May 22 19:37 UTC. Conjunction with Saturn in ecliptic longitude May 22 16:06 UTC. Conjunction with Neptune in ecliptic longitude May 22 19:15 UTC. Moon: 9.9° from Dabih in the Pathfinder.

Mars

Mars: naked eye at the Monday 00:00 UTC snapshot. At 45°N and 21:00 local apparent solar time, it is 38.2° above the horizon. Rises 10:04; sets 00:46 (45°N, local apparent solar time). Visual magnitude 1.2. The disk is 90.3% illuminated (gibbous). It is 76.0° from the Sun, on its east side. Motion is direct at 0.506° per day in ecliptic longitude at the snapshot. Position reference: Acubens, 6.8° away. Mars: 6.8° from Acubens in the Pathfinder.

Jupiter

Jupiter: naked eye at the Monday 00:00 UTC snapshot. At 45°N and 21:00 local apparent solar time, it is 5.4° above the horizon. Rises 06:10; sets 21:40 (45°N, local apparent solar time). Visual magnitude -1.9. The disk is 99.8% illuminated (nearly full). It is 26.9° from the Sun, on its east side. Motion is direct at 0.216° per day in ecliptic longitude at the snapshot. Position reference: Elnath, 6.0° away. Jupiter: 6.0° from Elnath in the Pathfinder.

Saturn

Saturn: naked eye at the Monday 00:00 UTC snapshot. At 45°N and 21:00 local apparent solar time, it is 46.2° below the horizon. Rises 02:23; sets 14:12 (45°N, local apparent solar time). Visual magnitude 1.1. The disk is 99.8% illuminated (nearly full). It is 58.8° from the Sun, on its west side. Motion is direct at 0.083° per day in ecliptic longitude at the snapshot. Position reference: Fumalsamakah, 15.3° away. Neptune is 2.2° away at the snapshot. Conjunction with Moon in ecliptic longitude May 22 16:06 UTC. Saturn: 15.3° from Fumalsamakah in the Pathfinder.

Uranus

Uranus: in solar glare at the Monday 00:00 UTC snapshot. Rises 04:31; sets 19:22 (45°N, local apparent solar time). Visual magnitude 5.8. The disk is 100.0% illuminated (nearly full). It is 0.9° from the Sun, on its west side. Motion is direct at 0.058° per day in ecliptic longitude at the snapshot. Position reference: Aldebaran, 13.8° away. Conjunction with Mercury in ecliptic longitude May 24 23:15 UTC. Uranus: 13.8° from Aldebaran in the Pathfinder.

Neptune

Neptune: telescope at the Monday 00:00 UTC snapshot. At 45°N and 21:00 local apparent solar time, it is 45.0° below the horizon. Rises 02:23; sets 14:24 (45°N, local apparent solar time). Visual magnitude 7.8. The disk is 100.0% illuminated (nearly full). It is 56.7° from the Sun, on its west side. Motion is direct at 0.024° per day in ecliptic longitude at the snapshot. Position reference: Fumalsamakah, 16.3° away. Saturn is 2.2° away at the snapshot. Conjunction with Moon in ecliptic longitude May 22 19:15 UTC. Conjunction with Ceres in ecliptic longitude May 22 00:37 UTC. Neptune: 16.3° from Fumalsamakah in the Pathfinder.

Ceres

Ceres: telescope at the Monday 00:00 UTC snapshot. At 45°N and 21:00 local apparent solar time, it is 52.9° below the horizon. Rises 03:04; sets 14:03 (45°N, local apparent solar time). Visual magnitude 9.3. The disk is 97.9% illuminated (gibbous). It is 58.0° from the Sun, on its west side. Motion is direct at 0.317° per day in ecliptic longitude at the snapshot. Position reference: Diphda, 11.7° away. Conjunction with Moon in ecliptic longitude May 22 19:37 UTC. Conjunction with Neptune in ecliptic longitude May 22 00:37 UTC. Ceres: 11.7° from Diphda in the Pathfinder.

Pluto

Pluto: substantial telescope at the Monday 00:00 UTC snapshot. At 45°N and 21:00 local apparent solar time, it is 34.1° below the horizon. Rises 00:20; sets 09:08 (45°N, local apparent solar time). Visual magnitude 14.5. The disk is 100.0% illuminated (nearly full). It is 114.5° from the Sun, on its west side. Motion is retrograde at 0.006° per day in ecliptic longitude at the snapshot. Position reference: Dabih, 8.2° away. Pluto: 8.2° from Dabih in the Pathfinder.