In the Sky This Week – May 26, 2020

Mars is now half-way across the southeastern predawn sky from Saturn and Jupiter, and is getting farther away from the pair with each day.

Mars in the southeastern predawn sky; Jupiter and Saturn in the southern predawn sky this week. Credit: Stellarium / Bob Trembley.

Mercury and Venus appear low on the northwestern horizon at sunset – the crescent Moon appears near the star Pollux on May 26th.

The waxing crescent Moon appears near the star Pollux in the western sky at sunset on May 26th; Mercury and Venus appear low on the horizon this week. Credit: Stellarium / Bob Trembley.

The Moon appears the star Regulus high in the west-southwestern sky after sunset on May 28 and 29th.

The Moon then appears near the star Spica, high in the southern sky after sunset on June 1st.

The Moon appears near the star Spica on June 1st high in the southern sky at 10:00 PM. Credit: Stellarium / Bob Trembley.

Asterisms galore in the east-northeastern sky at midnight this week: the Summer Triangle, the Northern Cross and the Mini-Cassiopeia – which I didn’t know was a thing… now I’ll have to go look for it!

Asterisms in the east-northeastern sky at midnight this week. Credit: Stellarium / Bob Trembley.

The Moon is a waxing crescent – visible toward the southwest in early evening.

The first quarter Moon occurs on Friday May 30th – visible high in the southern sky in the early evening.

After May 30th, the Moon will be a waxing gibbous – visible to the southeast in early evening, and up for most of the night.

The Moon from 2020-05-26 – 2020-06-01. Visualizations by Ernie Wright / NASA’s Scientific Visualization Studio.

The Sun has been spot-free for 24 days, apparently those 2 active regions rotating into view last week never developed into spots. Coronal loops from one of those regions are still visible in the videos below. The northern coronal hole remains open, but smaller than last week – the hole at the south pole is very large.

The Sun seen in 193 angstroms (extreme ultraviolet) May 25, 2020:

Beautiful, large, long-lived prominences on the Sun over the last few days!

The Sun seen in 304 angstroms (extreme ultraviolet) May 25, 2020:

Facebook: SolarActivity

https://www.facebook.com/photo.php?fbid=10222363879106729&set=gm.3226203814057607&type=3&theater&ifg=1

Solar Corona

Solar wind speed is 314.5 km/sec (↓), with a density of 6.4 protons/cm³ (↓) at 1210 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

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 May 25, 2020, the NASA All Sky Fireball Network reported 5 fireballs. 
(5 sporadics)

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 & Meteor News

Position of the planets and a couple spacecraft in the inner solar system.

Position of the planets and a couple spacecraft in the inner solar system, 2020-05-26 – the orbit of asteroid Eros is highlighted.. Credit: NASA Eyes on the Solar System / Bob Trembley.

Position of the planets in the middle solar system.

Position of the planets in the middle solar system, 2020-05-26 – the orbit of asteroid Eros is highlighted. Credit: NASA Eyes on the Solar System / Bob Trembley.

Position of the planets some transneptunian objects in the outer solar system.

Position of the planets in the outer solar system on 2020-05-26 – the orbit of transneptunian object 2007 OR10 is highlighted. Credit: NASA Eyes on the Solar System / Bob Trembley.

Solar System News

OSIRIS-REx: NASA’s Asteroid Sample Return Mission

International Space Station

Hubble Space Telescope

Juno Mission at Jupiter

HISTORY – Launch Complex 39: Apollo & Crew Dragon

SpaceX Crew Dragon Prepares to Launch to the International Space Station!

#LaunchAmerica: Kerbal Space Program Challenges Players to Recreate the Crew Dragon – NASA Approves!

Here’s some amazing KSP #LaunchAmerica footage:

https://twitter.com/The_ShadowZone/status/1263820944386265088

Climate

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.

Exoplanet Artwork

Artist’s concept of a crater lake on a body in a globular star cluster. Credit: SpaceEngine / Hap N Stance on Twitter.

The Local Stellar Neighborhood

Continuing with my visual tour of nearby stars and their systems, we travel to the Groombridge 34 star system, 11.6 light years distant.

Distance to Groombridge 34 from Sol; the plane (green) is aligned with the orientation of the plane of the Milky Way galaxy. Credit: SpaceEngine / Bob Trembley.

Groombridge 34

Groombridge 34 [Gliese 15 / SAO 36248 / HIP 1475 / HD 1326] is a binary star system in the northern constellation of Andromeda. It was listed as entry number 34 in A Catalogue of Circumpolar Stars, published posthumously in 1838 by British astronomer Stephen Groombridge. Based upon parallax measurements taken by the Gaia spacecraft, the system is located about 11.6 light-years from the Sun. This positions the pair among the nearest stars to the Solar System.

Both components are small, dim red dwarf stars that are too faint to be seen with the naked eye. They orbit around their common barycenter in a nearly circular orbit with a separation of about 147 AU and a period of around 2,600 years. Both stars exhibit random variation in luminosity due to flares and they have been given variable star designations: the brighter member Groombridge 34 A is designated GX And, while the smaller component is designated GQ And.

The star system has a relatively high proper motion of 2.9 arc seconds per year, and is moving away from the Solar System at a velocity of 11.6 km/s. It achieved perihelion some 15,000 years ago when it came within 11 ly (3.5 pc) of the Sun. – Wikipedia

Groombridge 34 System Architecture

Groombridge 34 system architecture. Credit: SpaceEngine / Bob Trembley.

Groombridge 34 (Gliese 15) System Orbital Diagram

Top-down view of the orbits of the stars in the Groombridge 34 star system – the system barycenter is highlighted. Credit: SpaceEngine / Bob Trembley.

Artist’s view of exoplanet Groombridge 34 Ab

In August 2014, a planet orbiting around Groombridge 34 A was reported. The planet’s existence was deduced from analysis of the radial velocities of the parent Star by the Eta-Earth Survey using HIRES at Keck Observatory. At the time of its discovery, it was the sixth-nearest known exoplanet.

Using the CARMENES spectrograph combined with the measurements of the HARPS and HIRES spectrographs, researchers failed to detect the purported Groombridge 34 Ab. However, they did propose another that another planet (Groombridge 34 Ac, GJ 15 Ac) could be orbiting the parent star.

This discrepancy was later reconciled with new HIRES observations, covering a longer span of time, where both planets were recovered, constraining their minimum mass to 3.03 M_⊕ for Groombridge 34 Ab and 36 M_⊕ for Groombridge Ac. Their orbital periods are 11.4 and approximately 7,600 days, respectively. To date, this is the multi-planet system closest to our Sun, hosting the longest period Neptune mass planet discovered so far. – Wikipedia

Artist’s concept of exoplanet Groombridge 34 Ab. 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