In the Sky This Week – February 25, 2020
The constellation Orion is moving slowly towards the west each evening; the star Betelgeuse has been dimming since last year, and is no longer in the top 25 brightest stars - which several of my astronomer friends have commented is "just weird!"
Orion appears west-southwestern sky at midnight this week. Credit: Stellarium / Bob Trembley.
As I was writing this post, I saw on SpaceWeather.com that apparently the dimming of Betelgeuse has stopped.
Betelgeuse hit bottom during the week of Feb. 7-13th with a magnitude slightly greater than +1.6. Based on observations, Betelgeuse has apparently stopped dimming and has started to slowly brighten. Credit: American Association of Variable Star Observers (AAVSO)
Predawn observers have three planets to choose from above the southeastern horizon: Saturn, Jupiter and Mars.
Saturn, Jupiter and Mars appear across the southeastern sky at 6:00 AM this week. Credit: Stellarium / Bob Trembley.
The crescent Moon joins Venus above the western horizon at dusk from February 25th - 28th.
The Moon appears near the star Aldebaran at 10:00 PM on March 1st - 2nd.
The Moon is a waxing crescent, visible toward the southwest in early evening.
The first quarter Moon occurs on March 2nd, it will be visible high in the southern sky in early evening.
The Moon from 2020-02-25 - 2020-03-02. Visualizations by Ernie Wright / NASA's Scientific Visualization Studio.
Click this image to go to the NASA 2020 Moon Phase and Libration site. Click the image of the Moon on that site to download a high-rez image of the current Moon phase with the names of craters and other features shown - many along the terminator.
Moon News: Historic NASA Mathematician Katherine Johnson Dies at Age 101
This morning, a NASA hero passed away at the age of 101.
We honor Katherine Johnson's pioneering spirit and incredible contributions to science and spaceflight. Her dedication and skill as a mathematician helped put humans on the Moon. https://t.co/dKW4zxhFau pic.twitter.com/zmuN6LKz49
— NASA Moon (@NASAMoon) February 24, 2020
The Sun has been spot-free for 23 days. The northern coronal hole remains diminished, while the southern coronal hole remains wide open. The Solar Dynamics observatory was eclipsed by the Moon for the first few frames of the videos below.
The Sun seen in 193 angstroms (extreme ultraviolet) Feb. 24, 2020:
Some beautiful large prominences on the Sun's limb over the last several days!
The Sun seen in 304 angstroms (extreme ultraviolet) Feb. 24, 2020:
You can view the Sun in near real-time, in multiple frequencies here: SDO-The Sun Now.
You can create your own time-lapse movies of the Sun here: AIA/HMI Browse Data.
You can browse all the SDO images of the Sun from 2010 to the present here: Browse SDO archive.
Here's a still of the SDO eclipse image:
The Sun eclipsed by the Moon on 2020-02-24 as seen by NASA's Solar Dynamics Observatory. Credit: NASA/SDO and the AIA, EVE, and HMI science teams
Facebook: SolarActivity
Solar Corona
Solar wind speed is 353.8 km/sec (↓), with a density of 1.8 protons/cm3 (↓↓) at 0947 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
Well done, MAG instrument and all teams involved 👍 #ForScience #WeAreAllSolarOrbiters https://t.co/wBbrZcMUHg
— ESA's Solar Orbiter (@ESASolarOrbiter) February 24, 2020
Potentially hazardous asteroids: 2018 (last updated Oct. 1, 2019)
Total Minor Planets discovered: 942,500 (+8358!!)
Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT)
|
Miss Distance
|
Velocity (km/s)
|
Diameter (m)
|
| 2020 DT2 |
2020-Feb-25
|
5.2 LD
|
11.9
|
11
|
| 2012 DS30 |
2020-Feb-26
|
12.3 LD
|
5.4
|
22
|
| 2020 DZ1 |
2020-Feb-27
|
7.4 LD
|
14.1
|
56
|
| 2020 DM2 |
2020-Feb-28
|
5.9 LD
|
4.9
|
12
|
| 2015 BK509 |
2020-Feb-29
|
18.7 LD
|
12.5
|
118
|
| 2020 DV1 |
2020-Feb-29
|
10.5 LD
|
15.6
|
53
|
| 2017 BM123 |
2020-Mar-01
|
10.5 LD
|
8.1
|
65
|
| 2018 RF6 |
2020-Mar-10
|
11.2 LD
|
12.6
|
36
|
| 2020 CA3 |
2020-Mar-10
|
13.8 LD
|
6.3
|
30
|
| 2008 UB95 |
2020-Mar-11
|
18.5 LD
|
7.6
|
41
|
| 2018 GY |
2020-Mar-15
|
6.2 LD
|
9.5
|
39
|
| 2012 XA133 |
2020-Mar-27
|
17.4 LD
|
23.7
|
235
|
| 2010 GD35 |
2020-Mar-29
|
15.3 LD
|
12
|
43
|
| 2006 FH36 |
2020-Mar-30
|
11.3 LD
|
5.1
|
93
|
| 2019 GM1 |
2020-Apr-02
|
9 LD
|
4.2
|
14
|
| 2015 FC35 |
2020-Apr-04
|
10.5 LD
|
13.8
|
148
|
| 2019 HM |
2020-Apr-10
|
7.2 LD
|
3.2
|
23
|
| 363599 |
2020-Apr-11
|
19.2 LD
|
24.5
|
224
|
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: Pallas Imaged Using Adaptive Optics on the Very Large Telescope
A very special #golfball: A study conducted by astronomers using ESO facilities has observed the asteroid Pallas for the first time at extremely high angular resolution.
Credit: @ESO /M. Marsset et al./MISTRAL algorithm (ONERA/CNRS) https://t.co/zS9qjMo5jk pic.twitter.com/2yVh4pdGIA
— ESO (@ESO) February 24, 2020
On Feb. 24, 2020, the NASA All Sky Fireball Network reported 6 fireballs.
(6 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). From: Spaceweather.com
Fireball & Meteor News: Meteorite Strike May Have Killed a Man in India!
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, 2020-02-25. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets in the middle solar system - asteroid 4 Vesta is highlighted:
Position of the planets in the middle solar system, 2020-02-25. Credit: NASA Eyes on the Solar System / Bob Trembley.
4 Vesta
Asteroid 4 Vesta. Image credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA
Vesta (minor-planet designation: 4 Vesta) is one of the largest objects in the asteroid belt, with a mean diameter of 525 kilometres (326 mi). It was discovered by the German astronomer Heinrich Wilhelm Matthias Olbers on 29 March 1807 and is named after Vesta, the virgin goddess of home and hearth from Roman mythology.
Vesta is the second-most-massive and probably the second-largest asteroid, after the dwarf planet Ceres, and contributes an estimated 9% of the mass of the asteroid belt. It is probably slightly larger than Pallas, but is about 25% more massive. Vesta is the only known remaining rocky protoplanet (with a differentiated interior) of the kind that formed the terrestrial planets. - Wikipedia
I covered Vesta and Ceres extensively in my series about NASA's Dawn mission.
3D Model of Vesta - go ahead and grab-and-drag it with your mouse!
Position of the planets in the outer solar system:
Position of the planets in the outer solar system, 2020-02-25. Credit: NASA Eyes on the Solar System / Bob Trembley.
OSIRIS-REx Asteroid Sample Return Mission
Smack dab in the middle of sample collection site Osprey.
Image details: https://t.co/00aO4G9ifY pic.twitter.com/UxceS7OaIp
— NASA's OSIRIS-REx (@OSIRISREx) February 24, 2020
Juno Mission at Jupiter
.@NASAJuno has measured the O/H ratio at Jupiter: 1.1-5.1 times the Solar value. This value, obtained at the equator, implies that the planetesimals that formed Jupiter were unlikely to have been water-rich. Li et al.: https://t.co/KmPxLuUwso pic.twitter.com/RdLRNmCA88
— Nature Astronomy (@NatureAstronomy) February 10, 2020
International Space Station
The Exp 62 crew spent Monday on a variety of human research activities and Earth observations. Read more... https://t.co/oyyJS0EPhC pic.twitter.com/5SJRiwwrr7
— Intl. Space Station (@Space_Station) February 24, 2020
Hubble Space Telescope
New evidence from Hubble indicates the shape of the Sombrero galaxy is the result of major galaxy mergers, though its smooth disk shows no signs of recent disruption: https://t.co/5V4dJIMvC7 pic.twitter.com/Zdphx1HeW8
— Hubble (@NASAHubble) February 20, 2020
Climate
Some parts of the Mississippi River Delta are disappearing due to sea-level rise, while other parts are not. A new NASA campaign, Delta-X, will be collecting data by air and by boat to better understand why. https://t.co/xJPIWVG375
— NASA Climate (@NASAClimate) February 21, 2020
Last month's global average concentration of atmospheric carbon dioxide (CO2) was about 413 parts per million (ppm), ⬆️ roughly 25 ppm from a decade ago. https://t.co/qjYgQZI1Al
— NASA Climate (@NASAClimate) February 21, 2020
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.
Eileen Grzybowski from Oklahoma shares what her and her students observed in the night sky as part of @GLOBEatNight. You can be a #CitizenScientist too! Click the link to learn how:https://t.co/OAJBMBG3hi pic.twitter.com/GMxtt18aeo
— IDA Dark-Sky (@IDADarkSky) February 24, 2020
Be the 1st in Feb to rate the brightness (or darkness) of your night sky https://t.co/YEK5j3OWnk Join GlobeatNight citizen-science campaign
— GLOBE at Night (@GLOBEatNight) February 2, 2016
The Local Stellar Neighborhood
Continuing with my visual tour of nearby stars and their systems, we travel to Sirius, 8.44 light years distant.
Distance to the Sirius star system from Sol; the plane (green) is aligned with the orientation of the Milky Way galaxy's plane. Credit: SpaceEngine / Bob Trembley.
Sirius
Sirius (/ˈsɪriəs/, designated α Canis Majoris (Latinized to Alpha Canis Majoris, abbreviated Alpha CMa, α CMa)) is the brightest star in the night sky. Its name is derived from the Greek word Σείριος Seirios "glowing" or "scorching". With a visual apparent magnitude of −1.46, Sirius is almost twice as bright as Canopus, the next brightest star. Sirius is a binary star consisting of a main-sequence star of spectral type A0 or A1, termed Sirius A, and a faint white dwarf companion of spectral type DA2, termed Sirius B. The distance between the two varies between 8.2 and 31.5 astronomical units as they orbit every 50 years.
-
- Top-down view of the orbits of the stars in the Sirius star system in 2020. Credit: SpaceEngine / Bob Trembley.
-
- Top-down view of the orbits of the stars in the Sirius star system in 2044. Credit: SpaceEngine / Bob Trembley.
Architecture of the Sirius star system. Credit: SpaceEngine / Bob Trembley.
Sirius appears bright because of its intrinsic luminosity and its proximity to the Solar System. At a distance of 2.64 parsecs (8.6 ly), the Sirius system is one of Earth's nearest neighbours. Sirius is gradually moving closer to the Solar System, so it will slightly increase in brightness over the next 60,000 years. After that time, its distance will begin to increase, and it will become fainter, but it will continue to be the brightest star in the Earth's night sky for the next 210,000 years. - Wikipedia
View of the orbits of the stars in the Sirius star system as seen from Earth. Credit: SpaceEngine / Bob Trembley.
Sirius A (right) seen from near Sirius B (left) at closest approach in 2044. Credit: SpaceEngine / Bob Trembley.
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.
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.
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.
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