Star Almanack
Alexander Ferrari Miller

ISO 2027-W39

Week begins: Monday, September 27, 2027

Notation:

Calendar

DateZodiac dayEvents
Mon, Sep 27, 2027♎ 5
Tue, Sep 28, 2027♎ 6
Kitalpha (α Equ) — Binoculars 4 — Tropical Autumn
Alderamin (α Cep) — Naked eye 2 — Northern Autumn
Wed, Sep 29, 2027♎ 7
Thu, Sep 30, 2027♎ 8
🌑 New Moon — 02:36:05 UTC
β Equ — Binoculars 5 — Tropical Autumn
Fri, Oct 1, 2027♎ 9
Alfirk (β Cep) — Naked eye 3 — Arctic Autumn
Sat, Oct 2, 2027♎ 10
M15 — Telescope 6 — Tropical Autumn
Sadalsuud (β Aqr) — Naked eye 3 — Tropical Autumn
M39 — Telescope 5 — Northern Autumn
Sun, Oct 3, 2027♎ 11
M2 — Telescope 7 — Tropical Autumn

Weekly Solar-System Ephemeris

Snapshot: Week begins September 27, 2027, 00:00 UTC.

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

Notation:
Body☉︎☽︎☿︎♀︎♂︎♃︎♄︎
Ecliptic♎︎ 3°40′
β −0°00′		♌︎ 21°10′
β −0°58′		♎︎ 29°40′
β −2°59′		♎︎ 16°07′
β +1°01′		♏︎ 16°43′
β −0°33′		♍︎ 13°26′
β +0°57′		♈︎ 26°01′
β −2°46′
ObservingNightNaked eye -7.9Naked eye 0.2☉︎Naked eye 1.4Naked eye -1.7Naked eye 0.2
Rise06:0102:2008:2707:0509:5204:1318:54
Set17:5916:1918:3818:3019:3417:2108:00

Extended targets:

Body⚳︎♅︎♆︎♇︎
Ecliptic♍︎ 26°02′
β +7°38′		♊︎ 9°54′
β −0°06′		♈︎ 5°17′
β −1°28′		♒︎ 4°51′
β −4°48′
Observing☉︎Binoculars 5.6Telescope 7.7TelescopeTelescope 14.6
Rise05:0620:4118:0316:01
Set18:2311:5706:1400:39

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 2026-10-22 20:52:07 UTC

View:

ISO 2027-W39 runs from September 27 through October 3. Uranus is about 0.1° in ecliptic longitude from Aldebaran in Taurus.

Naked eye: 🌑 New Moon — 02:36:05 UTC. The dark Moon favors faint targets and extended star fields. Use Alderamin, Alfirk, Sadalsuud as the week’s fixed-sky framework.

Alderamin: The Bright Star of Cepheus — An illuminating guide to the characteristics and significance of this notable celestial beacon.

Alfirk: A luminous beacon in Cepheus — Discover the characteristics and significance of this prominent star.

Sadalsuud: The Star of Fortunes in Aquarius — A detailed look at the luminous star Sadalsuud, its place in the constellation Aquarius, and its significance in the night sky.

Planets: Moon: Naked eye; magnitude -7.9; direct motion; 13.2% illuminated. Below the horizon at 21:00 local apparent solar time, 45°N. Monday 00:00 UTC snapshot. Solar conjunction in ecliptic longitude Sep 30 02:35 UTC. Conjunction with Mercury in ecliptic longitude Oct 01 23:22 UTC. Conjunction with Venus in ecliptic longitude Oct 01 02:51 UTC. Conjunction with Mars in ecliptic longitude Oct 03 06:42 UTC. Conjunction with Ceres in ecliptic longitude Sep 29 10:50 UTC. Conjunction with Jupiter in ecliptic longitude Sep 28 12:54 UTC. Mercury: Naked eye; magnitude 0.2; direct motion; 55.2% illuminated. Below the horizon at 21:00 local apparent solar time, 45°N. Monday 00:00 UTC snapshot. Conjunction with Moon in ecliptic longitude Oct 01 23:22 UTC. Venus: In solar glare; magnitude -3.9; direct motion; 97.7% illuminated. Monday 00:00 UTC snapshot. Conjunction with Moon in ecliptic longitude Oct 01 02:51 UTC. Mars: Naked eye; magnitude 1.4; direct motion; 94.4% illuminated. Below the horizon at 21:00 local apparent solar time, 45°N. Monday 00:00 UTC snapshot. Conjunction with Moon in ecliptic longitude Oct 03 06:42 UTC. Ceres: In solar glare; magnitude 8.5; direct motion; 99.9% illuminated. Monday 00:00 UTC snapshot. Conjunction with Moon in ecliptic longitude Sep 29 10:50 UTC. Jupiter: Naked eye; magnitude -1.7; direct motion; 99.9% illuminated. Below the horizon at 21:00 local apparent solar time, 45°N. Monday 00:00 UTC snapshot. Conjunction with Moon in ecliptic longitude Sep 28 12:54 UTC. Saturn: Naked eye; magnitude 0.2; retrograde motion; 100.0% illuminated. Monday 00:00 UTC snapshot. Uranus: Binoculars; magnitude 5.6; retrograde motion; 99.9% illuminated. Monday 00:00 UTC snapshot. Neptune: Telescope; magnitude 7.7; retrograde motion; 100.0% illuminated. Monday 00:00 UTC snapshot. Opposition in ecliptic longitude Sep 28 14:18 UTC. Pluto: Substantial telescope; magnitude 14.6; retrograde motion; 100.0% illuminated. Monday 00:00 UTC snapshot.

Binoculars: Trace Equuleus’s charted figure in the finder, then identify Kitalpha at its charted position. Trace Equuleus’s charted figure in the finder, then identify β Equ at its charted position.

Kitalpha: A Prominent Star of Equuleus — Illuminating insights into one of the constellation’s key stars, Kitalpha stands out as a notable figure in the night sky.

Beta Equulei: A Stellar Beacon in the Constellation Equuleus — An exploration of one of the notable stars nestled within the faint constellation of Equuleus, highlighting its characteristics and significance.

Small telescope: Great Pegasus Globular: consult its dedicated finder and observing story for equipment guidance; M39: consult its dedicated finder and observing story for equipment guidance; M2: consult its dedicated finder and observing story for equipment guidance

A star swarm with something strange at its heart — M15 is one of the densest globular clusters known, an ancient swarm whose brilliant center is crowded on a scale the quiet binocular glow does not suggest.

A cluster that wants a wide field — M39 is an open cluster whose loose bright stars make more sense together than they do one at a time.

A comet hunter found a city of 150,000 stars — M2 can look like a small misty ball, but the haze is the unresolved light of more than 150,000 stars bound together by gravity.

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

Other objects listed this week: None

Mercury

Mercury: naked eye at the Monday 00:00 UTC snapshot. At 45°N and 21:00 local apparent solar time, it is 25.3° below the horizon. Rises 08:27; sets 18:38 (45°N, local apparent solar time). Visual magnitude 0.2. The disk is 55.2% illuminated (gibbous). It is 26.2° from the Sun, on its east side. Motion is direct at 0.869° per day in ecliptic longitude at the snapshot. Position reference: Spica, 5.5° away. Conjunction with Moon in ecliptic longitude Oct 01 23:22 UTC. Mercury: 5.5° from Spica in the Pathfinder.

Venus

Venus: in solar glare at the Monday 00:00 UTC snapshot. Rises 07:05; sets 18:30 (45°N, local apparent solar time). Visual magnitude -3.9. The disk is 97.7% illuminated (gibbous). It is 12.5° from the Sun, on its east side. Motion is direct at 1.242° per day in ecliptic longitude at the snapshot. Position reference: Spica, 8.7° away. Conjunction with Moon in ecliptic longitude Oct 01 02:51 UTC. Venus: 8.7° from Spica 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 31.2° below the horizon. Rises 02:20; sets 16:19 (45°N, local apparent solar time). Visual magnitude -7.9. The disk is 13.2% illuminated (waning crescent). It is 42.5° from the Sun, on its west side. Motion is direct at 14.630° per day in ecliptic longitude at the snapshot. Position reference: Acubens, 8.2° away. Solar conjunction in ecliptic longitude Sep 30 02:35 UTC. Conjunction with Mercury in ecliptic longitude Oct 01 23:22 UTC. Conjunction with Venus in ecliptic longitude Oct 01 02:51 UTC. Conjunction with Mars in ecliptic longitude Oct 03 06:42 UTC. Conjunction with Ceres in ecliptic longitude Sep 29 10:50 UTC. Conjunction with Jupiter in ecliptic longitude Sep 28 12:54 UTC. Moon: 8.2° from Acubens 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 15.1° below the horizon. Rises 09:52; sets 19:34 (45°N, local apparent solar time). Visual magnitude 1.4. The disk is 94.4% illuminated (gibbous). It is 43.0° from the Sun, on its east side. Motion is direct at 0.688° per day in ecliptic longitude at the snapshot. Position reference: Zubenelgenubi, 1.5° away. Conjunction with Moon in ecliptic longitude Oct 03 06:42 UTC. Mars: 1.5° from Zubenelgenubi 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 32.2° below the horizon. Rises 04:13; sets 17:21 (45°N, local apparent solar time). Visual magnitude -1.7. The disk is 99.9% illuminated (nearly full). It is 20.3° from the Sun, on its west side. Motion is direct at 0.210° per day in ecliptic longitude at the snapshot. Position reference: Regulus, 13.2° away. Conjunction with Moon in ecliptic longitude Sep 28 12:54 UTC. Jupiter: 13.2° from Regulus 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 21.5° above the horizon. Rises 18:54; sets 08:00 (45°N, local apparent solar time). Visual magnitude 0.2. The disk is 100.0% illuminated (nearly full). It is 157.5° from the Sun, on its west side. Motion is retrograde at 0.070° per day in ecliptic longitude at the snapshot. Position reference: Alrescha, 7.3° away. Saturn: 7.3° from Alrescha in the Pathfinder.

Uranus

Uranus: binoculars at the Monday 00:00 UTC snapshot. At 45°N and 21:00 local apparent solar time, it is 2.3° above the horizon. Rises 20:41; sets 11:57 (45°N, local apparent solar time). Visual magnitude 5.6. The disk is 99.9% illuminated (nearly full). It is 113.8° from the Sun, on its west side. Motion is retrograde at 0.010° per day in ecliptic longitude at the snapshot. Position reference: Aldebaran, 5.4° away. Uranus: 5.4° 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 29.3° above the horizon. Rises 18:03; sets 06:14 (45°N, local apparent solar time). Visual magnitude 7.7. The disk is 100.0% illuminated (nearly full). It is 177.8° from the Sun, on its west side. Motion is retrograde at 0.028° per day in ecliptic longitude at the snapshot. Position reference: Fumalsamakah, 19.4° away. Opposition in ecliptic longitude Sep 28 14:18 UTC. Neptune: 19.4° from Fumalsamakah in the Pathfinder.

Ceres

Ceres: in solar glare at the Monday 00:00 UTC snapshot. Rises 05:06; sets 18:23 (45°N, local apparent solar time). Visual magnitude 8.5. The disk is 99.9% illuminated (nearly full). It is 10.8° from the Sun, on its west side. Motion is direct at 0.460° per day in ecliptic longitude at the snapshot. Position reference: Denebola, 6.1° away. Conjunction with Moon in ecliptic longitude Sep 29 10:50 UTC. Ceres: 6.1° from Denebola 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 20.6° above the horizon. Rises 16:01; sets 00:39 (45°N, local apparent solar time). Visual magnitude 14.6. The disk is 100.0% illuminated (nearly full). It is 121.1° from the Sun, on its east side. Motion is retrograde at 0.010° per day in ecliptic longitude at the snapshot. Position reference: Dabih, 9.4° away. Pluto: 9.4° from Dabih in the Pathfinder.