Cassiopeia E And The Mystery Scientists Still Examine
- 01. What Is Cassiopeia e?
- 02. Epsilon Cassiopeiae (Segin): The Star Scientists Study
- 03. Key Physical Properties of Segin
- 04. Why Segin Remains a Scientific Mystery
- 05. How to Locate Segin in the Night Sky
- 06. Casio Cassiopeia E-10: The Handheld Computer
- 07. Cassiopeia E-10 Technical Specifications
- 08. Frequently Asked Questions
What Is Cassiopeia e?
"Cassiopeia e" most commonly refers to Epsilon Cassiopeiae (ε Cas), the blue-white star officially named Segin that marks the leftmost point of Cassiopeia's iconic W-shaped asterism. The lowercase "e" is a shorthand for the Greek letter epsilon (ε) in Bayer designation notation. Segin lies approximately 410 light-years from Earth, has an apparent magnitude of 3.37, and is the fifth-brightest star in the Cassiopeia constellation.
Alternatively, "Cassiopeia E" may refer to the Casio Cassiopeia E-10, a palm-sized PDA released in June 1998 that ran Windows CE 2.01 and featured a 240x320 grayscale display. This handheld computer weighed just 184 grams and offered up to 25 hours of battery life.
Epsilon Cassiopeiae (Segin): The Star Scientists Study
Segin is a B3 V main-sequence star fusing hydrogen in its core, with a mass 9.2 times that of the Sun and a radius 6 times solar. Its effective temperature of 15,174 K makes it shine with 2,500 solar luminosities, appearing blue-white to observers.
Key Physical Properties of Segin
| Property | Value | Reference |
|---|---|---|
| Spectral Class | B3 V (main sequence) or B3 III (giant) | |
| Apparent Magnitude | 3.37 | |
| Absolute Magnitude | -2.19 | |
| Distance from Earth | 410 ± 20 light-years (126 ± 7 parsecs) | |
| Mass | 9.2 ± 0.2 M☉ | |
| Luminosity | 2,500 L☉ | |
| Radius | 6 R☉ | |
| Temperature | 15,174 K | |
| Age | 15.4 ± 3.0 million years |
Why Segin Remains a Scientific Mystery
Scientists continue to examine Segin because it presents contradictory classifications: it is sometimes listed as a main-sequence dwarf (B3 V) and other times as a giant star (B3 III). A 1993 study identified Segin as one of the known Be stars-Class B stars with hydrogen emission lines indicating a circumstellar gas disk-yet it lacks the formal "e" or "shell" classification in the Bright Star Catalogue.
Hipparcos satellite measurements in the early 1990s revealed Segin may be a slightly variable star, with brightness fluctuating by 0.0025 magnitude over 2.15 hours. This periodic variability remains unexplained and suggests possible pulsations or rotational effects.
- Segin is part of the disputed Cassiopeia-Taurus (Cas-Tau) moving group, with a 93% likelihood of membership
- The star likely separated from the Alpha Persei Cluster through tidal interactions over time
- At only 15.4 million years old, Segin is among the youngest prominent stars in Cassiopeia's W
- It is the faintest of the five W stars despite being the second most distant, behind only Gamma Cassiopeiae
How to Locate Segin in the Night Sky
Segin is very easy to find because it forms the leftmost point of Cassiopeia's W, one of the most familiar star patterns in the northern sky. The asterism appears as a W during northern hemisphere spring and summer, and inverted during winter months.
- Find the distinctive W-shaped asterism of Cassiopeia in the northern sky
- Identify the leftmost star of the W-that is Segin (Epsilon Cassiopeiae)
- Look west of Segin for open clusters NGC 637 (mag. 8.2), NGC 609 (mag. 11), and NGC 559 (mag. 9.5)
- Look east-southeast for the Heart and Soul nebulae (IC 1805 and IC 1848) and the Double Cluster (NGC 869 and NGC 884)
- Best viewing occurs in November, when Cassiopeia is prominent in the evening sky
Casio Cassiopeia E-10: The Handheld Computer
If your search refers to technology rather than astronomy, the Casio Cassiopeia E-10 was a pioneering palm-sized PC released in June 1998 into North America. This device represented Casio's response to consumer demand for smaller PDAs after their larger keyboard-equipped models.
Cassiopeia E-10 Technical Specifications
| Specification | Detail |
|---|---|
| Operating System | Microsoft Windows CE 2.01 Palm-size PC edition |
| Dimensions | 80 mm x 120 mm x 20 mm |
| Weight | 184 grams |
| CPU | NEC VR4111 MIPS at 69 MHz |
| Memory | 4 MB RAM, 8 MB ROM |
| Display | 240 x 320 pixels, 4-shade grayscale FSTN LCD |
| Battery Life | Up to 25 hours (2x AAA) |
| Expansion | CompactFlash Type I and II slots |
| Input | Touch screen, microphone, 4 user buttons, control pad |
Frequently Asked Questions
Helpful tips and tricks for Cassiopeia E And The Mystery Scientists Still Examine
What does the "e" in Cassiopeia e mean?
The lowercase "e" represents the Greek letter epsilon (ε) in Bayer designation notation, so "Cassiopeia e" = Epsilon Cassiopeiae (ε Cas), the star officially named Segin.
How far away is Segin (Epsilon Cassiopeiae)?
Segin is located approximately 410 ± 20 light-years (126 ± 7 parsecs) from Earth, making it the second most distant of the five stars forming Cassiopeia's W.
Is Cassiopeia e a variable star?
Yes, Hipparcos measurements suggest Segin is a slightly periodic variable star, with brightness varying by 0.0025 magnitude over a 2.15-hour period, though the cause remains under study.
When was the Casio Cassiopeia E-10 released?
The Casio Cassiopeia E-10 was introduced into North America in June 1998, running Windows CE 2.01 with a 240x320 grayscale display.
Why do scientists still examine Segin?
Scientists continue studying Segin because it has contradictory spectral classifications (dwarf vs. giant), may be a Be star without formal classification, shows unexplained periodic variability, and provides insight into young massive star evolution at only 15.4 million years old.
What is the best time to see Cassiopeia's W?
The best time to see Cassiopeia is during November, when the constellation reaches its height in the sky at 10:00 pm and is most prominent in the evening sky.
