In the Sky This Week – October 13, 2020

Venus appears in the eastern predawn sky all week; the waning crescent Moon appears near Venus on the mornings of Oct. 13th and 14th.

Saturn and Jupiter appear in the southern sky after sunset.

Saturn and Jupiter appear in the southern sky after sunset, and set in the southwest around midnight. Credit: Stellarium / Bob Trembley.

Mars is at opposition – when it and the Earth are in-line with the Sun; this is also when Mars is closest to the Earth in their orbits, so now is a great time to go observe Mars!

Mars appears in the eastern sky after sunset, is high in the southeastern sky at midnight, and sets in the west with the sunrise. Credit: Stellarium / Bob Trembley.

Here’s a close-up of the Mars opposition:

Mars Opposition on 2020-10-13. Credit: SpaceEngine / Bob Trembley.

The Moon is a waning crescent – visible low to the east before sunrise.

The new Moon occurs on Oct. 16th – the Moon will not be visible at this time… unless it get’s smacked by an asteroid…

The Moon returns to the southwestern sky at dusk as a waxing crescent by early next week.

The Moon from 2020-10-13 – 2020-10-19. Visualizations by Ernie Wright / NASA’s Scientific Visualization Studio.

If you click on the Moon image above, or click this link, you will go to NASA’s Moon Phase and Libration, 2020 page – it will show you what the Moon looks like right now. If you click the image on that page, you will download a high-rez TIF image annotated with the names of prominent features – helpful for logging your observations!

Annotated close-up of a section of the Moon on Oct. 14th. Visualizations by Ernie Wright / NASA’s Scientific Visualization Studio.

Moon News

The Sun has a spot! AR2775 was indicated on SpaceWeather.com, but I could not see it even in the 4K hi-rez image – you can see where it is in the video below, it’s in the lower right, with a lot of coronal loop activity. Large coronal holes are open at both poles.

The Sun seen in 193 angstroms (extreme ultraviolet) October 12, 2020:

Prominences galore… again! Lots of  activity over the last several days!

The Sun seen in 304 angstroms (extreme ultraviolet) October 12, 2020:

Solar Activity on Facebook – Run by Volunteer NASA/JPL Solar System Ambassador Pamela Shivak

The SOLARACTIVITY PICTURE OF THE DAY for October 13th, 2020 is this full disk image by Rossana Miani.
Equipment details: Skywatcher AZEQ5, ASI 174MM, SolarMax II 60mm, Barlow2x.

Solar Corona

Solar wind speed is 292.8 km/sec (↓), with a density of 15.7 protons/cm³ (↑↑) at 1204 UT.

Near real-time animation of the corona and solar wind from the Solar & Heliospheric Observatory (SOHO):

Animated LASCO C2 Coronograph showing the solar corona above the Sun’s limb (the white circle). Credit: NASA/JPL-Caltech-SOHO

Sun News

Upcoming Earth-asteroid encounters:

Notes: LD means “Lunar Distance.” 1 LD = 384,401 km, the distance between Earth and the Moon. Red highlighted entries are asteroids that either pass very close, or very large with high relative velocities to the Earth. Table from SpaceWeather.com

Asteroid News:

On October 12, 2020, the NASA All Sky Fireball Network reported 21 fireballs. 
(20 sporadics, 1 Southern Taurid)

In this diagram of the inner solar system, all of the fireball orbits intersect at a single point–Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). Credit: SpaceWeather.com

Fireball News: Meteorite Fall in Northeastern Mexico!

Position of the planets in the inner solar system:

Position of the planets in the inner solar system, 2020-10-13. Credit: SpaceEngine / Bob Trembley.

Position of the planets in the middle solar system:

Position of the planets, and dwarf planet Ceres in the inner solar system, 2020-10-13. Credit: SpaceEngine / Bob Trembley.

Position of the planets, some dwarf planets and some transneptunian objects in the outer solar system – the orbit of transneptunian object (TNO) Eris is highlighted.

Position of the planets and several transneptunian objects in the outer solar system, 2020-10-13. Credit: SpaceEngine / Bob Trembley.

NASA’s OSIRIS-REx Asteroid Sample Return Mission:

International Space Station:

Mars HiRISE:

Mars Reconnaissance Orbiter:

Climate: Having a grandchild changes the way you look at Earth’s future

See a list of current NASA missions here: https://www.jpl.nasa.gov/missions/?type=current

ex·o·plan·et /ˈeksōˌplanət/, noun: a planet orbiting a star other than the Sun.

Data from the NASA Exoplanet Archive
* Confirmed Planets Discovered by TESS refers to the number planets that have been published in the refereed astronomical literature.
* TESS Project Candidates refers to the total number of transit-like events that appear to be astrophysical in origin, including false positives as identified by the TESS Project.
* TESS Project Candidates Yet To Be Confirmed refers to the number of TESS Project Candidates that have not yet been dispositioned as a Confirmed Planet or False Positive.

Hubble: Beautiful Universe

Tour of the Local Stellar Neighborhood

Continuing with my visual tour of nearby stars and their systems, we travel to the Gliese 229 system, about 19 light years distant.

Gliese 229 is about 19 light years from Sol; the plane (green) is aligned with the orientation of the plane of the Milky Way galaxy. Credit: SpaceEngine / Bob Trembley.

Gliese 229

Gliese 229 (also written as Gl 229 or GJ 229) is a binary system composed of red dwarf and brown dwarf about 19 light years away in the constellation Lepus. Primary component has 58% of the mass of the Sun, 69% of the Sun’s radius, and a very low projected rotation velocity of 1 km/s at the stellar equator.

The star is known to be a low activity flare star, which means it undergoes random increases in luminosity because of magnetic activity at the surface. The spectrum shows emission lines of calcium in the H and K bands. The emission of X-rays has been detected from the corona of this star. These may be caused by magnetic loops interacting with the gas of the star’s outer atmosphere. No large-scale star spot activity has been detected.

The space velocity components of this star are U = +12, V = –11 and W = –12 km/s. The orbit of this star through the Milky Way galaxy has an eccentricity of 0.07 and an orbital inclination of 0.005.

A substellar companion was discovered in 1994 by Caltech astronomers Kulkarni, Tadashi Nakajima, Keith Matthews, and Rebecca Oppenheimer, and Johns Hopkins scientists Sam Durrance and David Golimowski. It was confirmed in 1995 as Gliese 229B, one of the first two instances of clear evidence for a brown dwarf, along with Teide 1. Although too small to sustain hydrogen-burning nuclear fusion as in a main sequence star, with a mass of 21 to 52.4 times that of Jupiter (0.02 to 0.05 solar masses), it is still too massive to be a planet. As a brown dwarf, its core temperature is high enough to initiate the fusion of deuterium with a proton to form helium-3, but it is thought that it used up all its deuterium fuel long ago. This object now has a surface temperature of 950 K.

In March 2014, a super-Neptune mass planet candidate was announced in a much closer-in orbit around GJ 229. Given the proximity to the Sun, the orbit of GJ 229Ab might be fully characterized by the Gaia space-astrometry mission or via direct imaging. In 2020, a super-Earth mass planet was discovered around GJ 229. It orbits the star closer in than GJ 229Ab, and is located in the star’s habitable zone.  – Wikipedia

Orbit of Red Dwarf Gliese 229 A

This is a REALLY unusual system! When I was composing the images below, I centered on the exoplanet, and time-accelerated until the companion brown dwarf was in the frame with the band of the Milky Way; because the brown dwarf orbits so far away from the red dwarf, it does not move very fast across the sky. BUT! Because of the high inclination of the exoplanet, the brown dwarf appears to loop up and down! Very strange!

Orbit of Exoplanet Gliese 229 A b (red) around Red Dwarf Gliese 229 A, and orbit of Gliese 229 A (green) around the Gliese 229 Barycenter. Credit: SpaceEngine / Bob Trembley.

Orbit of Brown Dwarf Gliese 229 B

Orbit of Brown Dwarf Gliese 229 B around Gliese 229 Barycenter. Credit: SpaceEngine / Bob Trembley.

Artist’s Rendering of a Neptune-like Exoplanet Orbiting Red Dwarf Gliese 229 A

Artistic rendering of Exoplanet Gliese 229 A b – Brown Dwarf Gliese 229 B is in the distance to the right. Credit: SpaceEngine / Bob Trembley.

Artist’s Rendering of Brown Dwarf Gliese 229 B

Artistic rendering of Brown Dwarf Gliese 229 B – Red Dwarf Gliese 229 A is in the distance to the left. Credit: SpaceEngine / Bob Trembley.

Stay safe, be well, and look up!

Apps used for this post:

NASA Eyes on the Solar System: an immersive 3D solar system and space mission simulator – free for the PC /MAC. I maintain the unofficial NASA Eyes Facebook page.
Universe Sandbox: a space simulator that merges real-time gravity, climate, collision, and material interactions to reveal the beauty of our universe and the fragility of our planet. Includes VR support.
SpaceEngine: a free 3D Universe Simulator for Windows. Steam version with VR support available.
Stellarium: a free open source planetarium app for PC/MAC/Linux. It’s a great tool for planning observing sessions. A web-based version of Stellarium is also available.

Section header image credits:
The Sky – Stellarium / Bob Trembley
Observing Target – Turn Left at Orion / M. Skirvin
The Moon – NASA/JPL-Caltech
The Sun – NASA/JPL-Caltech
Asteroids – NASA/JPL-Caltech
Fireballs – Credited to YouTube
Comets – Comet P/Halley, March 8, 1986, W. Liller
The Solar System – NASA Eyes on the Solar System / Bob Trembley
Spacecraft News – NASA Eyes on the Solar System / Bob Trembley
Exoplanets – Space Engine / Bob Trembley
Light Pollution – NASA’s Black Marble
The Universe – Universe Today