Wonders of Space

Observatory / Course Archives / ASTR 110 Fall 2019 / Calderon-Crain

Eta Carinae

Above is a picture of Eta Carnie Galaxy, a stellar system that has two stars that has an illuminosity greater than our Sun.

Discussion:

• Distance, size, constellations: Carina constellation (located in the Carina–Sagittarius Arm);about 90 times the mass of the Sun and is 5 million times more luminous. 7,500 light years away from Earth
• Historical Facts: During the 19th century outburst, the star threw off over 10 solar masses into space, which now form the surrounding nebula.The international team of researchers used the Very Large Telescope and its X-Shooter spectrograph at the European Southern Observatory in Chile , and created the most complete spectral map of the nebula to date.
• The Eta Carinae system has at least two stars. The primary star is classified as a luminous blue variable (LBV). The secondary component is a hot supergiant orbiting the primary star. Companion is completely invisible in optical wavelengths because it is enveloped in the thick nebula around Eta Carinae

Interesting facts:

• The nebula is one of the largest diffuse nebulae in our skies.
• Has been monitored for more than two decades
• Largest member of a double-star system

Interpretation:

• Color: Has a glow of magnesium in the warm gas
• Structures: Dark globules and some other less visible objects have tails pointing directly away from the massive star. The entire nebula would have looked very different before the Great Eruption in the 1840s surrounded Eta Carinae with dust, drastically reducing the amount of ultraviolet light it put into the nebula.
• Why it looks the way it does: Eta Carinae was enveloped by a cloud of dust ejected during a violent outburst.In adult life, went through a series of eruptions resulting in illuminosity to increase before fading away. Hypothesis: One explanation for the monster star's antics is that the convulsions were caused by a complex interplay of as many as three stars, all gravitationally bound in one system. The most massive member – weighing in at 150 times our Sun's mass – swallowed one of the stars. Potential reason for outburst in the 1840s.
• What is expected to happen: explode into Super Nova

Southern Crab Nebula

The Southern Crab Nebula is an interstellar cloud of dust, hydrogen, helium and other ionized gases

• Most nebulae of vast size; some are hundreds of light-years in diameter. A nebula that is visible to the human eye from Earth would appear larger, but no brighter, from close by.
• Some nebulae form from gas that is already in the interstellar medium while others are produced by stars. Examples of the former case are giant molecular clouds, the coldest, densest phase of interstellar gas, which can form by the cooling and condensation of more diffuse gas. Examples of the latter case are planetary nebulae formed from material shed by a star in late stages of its stellar evolution

Discussion

• Officially known as Hen 2-104
• Located several thousand light-years from Earth in the Southern hemisphere constellation of Centaurus
• Consist of an aging red giant star and a burned-out white dwarf.
  • Red giant will eventually collapse to become a white dwarf
• It appears to have two nested hourglass-shaped structures that were sculpted by a whirling pair of stars in a binary system.
  • Complicated nested structures discovered in 1999
  • This belt of material constricts the outflow of gas so that it only speeds away above and below the disk. The result is an hourglass-shaped nebula.
• Latest images were taken in March 2019
  • Shows various colors of light that correspond to the glowing gases in the nebula.
• The Southern Crab was noted in a 1967 catalog, and was also observed using a CCD imager with the 2.2 meter telescope at the La Sila observatory in 1989.The 1989 observation marked a major expansion of knowledge about the nebula, and it was observed using various filters.
• Hubble Space Telescope in 1999 have provided much more detail, revealing that at the center of the nebula are a pair of stars, a red giant and a white dwarf. It was imaged again by HST in 2019 with a newer instrument.

The nebula was imaged again by the Hubble Space Telescope in 2019, and a set of images to celebrate the anniversary of the space telescope's launch in 1990 (29 years) by the Space Shuttle. This time a newer camera the WFC3 was used to image the nebula, at wavelengths filters of about 502, 656, 658, and 673 nanometers.

Interpretation

• This peculiar nebula, which exhibits nested hourglass-shaped structures, has been created by the interaction between a pair of stars at its centre
• was assumed to be an ordinary star until 1989, when it was observed using telescopes at the European Southern Observatory's La Silla Observatory.
• Eventually, the red giant will finish throwing off its outer layers, and stop feeding its white dwarf companion. Prior to this, there may also be more eruptions, creating even more intricate structures.
• The Southern Crab Nebula, named after its resemblance to its northern counterpart the Crab Nebula, is distinctive due to its 'peculiar' hourglass-shaped structure, according to the European Space Agency (ESA).

A red giant star and a white dwarf star sit at the center of the nebula, forming a binary star system.

The images document in stunning detail how the red giant continuously expels material that's absorbed by the white dwarf, in what NASA described as a 'gravitational waltz,' that results in the hourglass-like shape.

51 Pegasus b

An exoplanet meets most of the criteria to be a planet with the exception of them not being able to clear an area due to this massive gravitational force and because they all do not orbit the sun. Exoplanets are very hard to see directly with telescopes. They are hidden by the bright glare of the stars they orbit. We are able to search for exoplanets by looking for a “wobble” from their closest star. Kepler (space craft) looked for planets in a wide range of sizes and orbits. And these planets orbited around stars that varied in size and temperature.

Discussion:

• Type of object: Exoplanet
• Interesting facts
• Launched a new field in astronomical research
• 1st planet to have its reflected visible light spectrum detected
• 1st conformed around a sun-like star.
• Astronomers have detected the presence of water molecules in the atmosphere of a nearby hot Jupiter exoplanet known as 51 Pegasi b (51 Peb b for short).

Historical facts:

• Discovered Oct 6, 1995 by Michel Mayor and Didier Queloz using the ELDIE spectrograph at the Observatoire de Haute-Provence
• Confirmed by Geoff Marcy and Paul Butler using the Hamilton Spectrograph at the Lick Observatory
• distance , size, constellation:
• 1800F aka HOT.
• 50 light-years away from Earth
• 47% less massive but 50% larger than Jupiter
• 11% more massive and 23% larger than our sun
• Orbits its star about every 4 days
• In constellation Pegasus

Interpretation

• Color: It was first speculated that 51 Pegasi b was the stripped core of a brown dwarf of a decomposed star and was therefore composed of heavy elements, but it is now believed to be a gas giant . It is sufficiently massive that its thick atmosphere is not blown away by the star's solar wind.
• Structures astrophysically
• 51 Pegasi b probably has a greater radius than that of Jupiter despite its lower mass. because its superheated atmosphere must be puffed up into a thick but tenuous layer surrounding it. Beneath this, the gases that make up the planet would be so hot that the planet would glow red. Clouds of silicates may exist in the atmosphere.