STF 2840 Position and Visibility Tonight
Where is STF 2840 right now?
STF 2840 is located in the constellation Cepheus. It is currently above the horizon at an altitude of 69° toward the north-east, with an apparent magnitude of 5.64.
STF 2840 visibility on 2026-10-25
STF 2840 Visible all night
STF 2840 rise and set timetable
| Time | Elevation | |
| STF 2840 is always above the horizon | ||
Moonrise, 98.1% illuminated  | 15:17 | 51° |
| Sunset | 16:17 | 59° |
| Civil sunset | 16:45 | 63° |
| Twilight start (−12°) | 17:15 | 66° |
| Astronomical observing session begins | 17:46 | 69° |
| STF 2840 is always above the horizon | ||
| STF 2840 transit | 18:45 | 72° |
| Astronomical observing session ends | 03:58 | 10° |
| Twilight end (−12°) | 04:28 | 8° |
| Moonset | 04:57 | 6° |
| Civil sunrise | 04:58 | 6° |
| Sunrise | 05:26 | 5° |
Track STF 2840 position throughout the night
← 25 October 2026 →
| Time | |
| Altitude | |
| Azimuth |
Shift the map to change the time and observe STF 2840 changing position in the night sky.
Star system description: STF 2840
A double or multiple star system in Cepheus.
Pair AB has a measured separation of 18.3″; a telescope may be needed to split it.
The diagram uses the latest WDS measurements; north is up and east is right. Measurements may be from different years. Unconnected groups are arranged separately; close pairs may merge, and pairs without reliable geometry are omitted.
Technical details: STF 2840
| Property | Value |
|---|---|
| System identifier | WDS 21520+5548 |
| Bayer / Flamsteed designation | |
| Constellation | Cepheus |
| System type | multiple star system |
| Right ascension (RA) | 21h 52m 01s" |
| Declination (Dec) | 55° 47' 48s |
| Component | AB |
| Primary magnitude | 5.64 |
| Secondary magnitude | 6.42 |
| Separation (arcseconds) | 18.3″ |
| Position angle | 197° |
| Discovery year | 1782 |
| Last observed | 2025 |
| Spectral type (primary/secondary) | B6IV-V |
| Number of observations | 113 |
3 components are identified in WDS; this is not a count of resolved stars.
Components of STF 2840
Each row is a separate WDS component pair. Measurements may come from different years.
| Component | Primary magnitude | Secondary magnitude | Separation (arcseconds) | Position angle | Last observed |
|---|---|---|---|---|---|
| AB | 5.64 | 6.42 | 18.3″ | 197° | 2025 |
| AC | 5.64 | 13.10 | 54.9″ | 345° | 2015 |
Notes
- U: Proper motion indicates a non-physical pair.
Data source: Washington Double Star (WDS) Catalog. Maintained by the U.S. Naval Observatory; thanks to the WDS team.
Finder Chart for STF 2840
STF 2840 Passage Through Night
Double-click to unlock the map.
Current position of STF 2840
| Time | 17:42 |
| Latitude | 37.3541 |
| Longitude | -121.955 |
| Elevation | 69° |
| Azimuth | 25° |
Here you can see the current position of STF 2840 on the map, as well as its positions for rise and set. This tool lets you track its movement throughout the night with accurate, up-to-date information.
When Is STF 2840 Visible Throughout the Year?
STF 2840 will remain visible until February 11, when it moves too close to the Sun and temporarily disappears from the night sky.
| Date | Mon, 26 October 2026 |
| Astronomical observing session begins | 17:44 |
| Astronomical observing session ends | 03:56 |
| Astronomical observing duration | 10h 12m |
| Rise | 21520+5548 is always up |
| Set | 21520+5548 is always up |
| Elevation at transit | 72° |
| Transit time | 18:41 |
| Equatorial coordinates | RA: 21h 52m 01s", Dec: 55° 47' 48s |
| Magnitude | 6 |
| Constellation | Cepheus |
The graph illustrates the annual visibility pattern of STF 2840, including its daily appearances and transit times. The vertical axis shows the hours of the day and the horizontal axis spans the year. The reddish area marks when the object is above the horizon, while the white line marks its daily transit.
You can also see when STF 2840 is visible throughout the year in a table with exact rise, transit, and set times for each date.
You can also see when STF 2840 is visible throughout the year in a table with exact rise, transit, and set times for each date.
Astrometric and Physical Parameters of STF 2840
Coordinates and Visibility
| Right Ascension | 21h 52m 01s |
| Declination | 55° 47′ 48″ |
| Magnitude | 5.64 |
| Constellation | Cepheus |
| Elevation | 68.7° |
| Azimuth | 24.8° |