In the Sky This Week – December 15, 2020
Jupiter and Saturn appear in the southwestern sky at dusk, getting closer getting closer to the Dec. 21 conjunction with each passing day! The waxing crescent Moon joins the pair of planets on Dec. 16 & 17.
Saturn and Jupiter appear in the southwestern sky at dusk. Credit: Bob Trembley / Stellarium.
Venus appears in the southeastern predawn sky all week, getting closer to the horizon with each passing day.
Venus appears in the southeastern predawn sky. Credit: Bob Trembley / Stellarium.
Mars, Uranus, the Pleiades star cluster and the bright star Aldebaran appear in the east-southeastern sky after sunset this week.
Mars, Uranus, the Pleiades and Aldebaran appear in the east-southeastern sky after sunset this week. Credit: Bob Trembley / Stellarium.
The constellation Lyra, with the bright star Vega appear above the western horizon after sunset this week.
The constellation Lyra appears above the western horizon after sunset this week. Credit: Bob Trembley / Stellarium.
The Moon is a waxing crescent- visible toward the southwest in early evening.
The first quarter Moon occurs on Dec, 21st - visible high in the southern sky in early evening.
The Moon from 2020-12-15 - 2020-12-21. 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!
Moon News
The first woman will reach the Moon with @NASAArtemis & there has never been a better time to introduce young women to STEM. 🌙 👩🚀
The #Artemis Moon Pod Essay Contest for K-12 students gives them a chance to envision their own lunar journey: https://t.co/GpOnEGGXPd pic.twitter.com/lhFSuzZgIr
— Women@NASA on the Moon with #Artemis. (@WomenNASA) December 13, 2020
There was a total solar eclipse on Dec. 14th - the Moon's shadow crossed over the South America.
For those not in the path of the eclipse, you can view a livestream here: https://t.co/T4yXkjkwUw pic.twitter.com/HNfxzVuGsm
— NASA Moon (@NASAMoon) December 14, 2020
#Eclipse2020 With rain and clouds. 🌧️🌫️
Villarrica volcano, Chile. pic.twitter.com/Qq9F1CTyPp— ALMA Observatory at Home📡 (@almaobs) December 14, 2020
The Sun has 2 sunspots. Sunspot AR2792 is energetic and poses a threat for C-class solar flares; on Dec. 14th it blew off a C4-class flare, with a coronal mass ejection (CME).
The Sun on Dec. 15, 2020. Credit: SDO/HMI. Source: SpaceWeather.com
The limb of the Sun where these sunspots are rotating into view show a lot of coronal activity. Both the northern ans southern coronal holes appear to be a bit... lop-sided.
The Sun seen in 193 angstroms (extreme ultraviolet) December 14, 2020:
Lots of prominence activity over the last couple days - time for me to get that new mount for my solar telescope!
The Sun seen in 304 angstroms (extreme ultraviolet) December 14, 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.
Solar Activity on Facebook - Run by Volunteer NASA/JPL Solar System Ambassador Pamela Shivak
SOLARACTIVITY PICTURE OF THE DAY for Tuesday, December 15th, 2020 goes to Eduardo Schaberger Poupeau for this awesome partial of today's Solar eclipse. Eduardo commented: "Today in the south of my country, Argentina, there was a total solar eclipse, due to the pandemic and the difficulties in traveling, I decided to stay in my city where the eclipse was only 62%. Anyway always an eclipse in an event that is enjoyed a lot. This photo was taken during the maximum, with a Coronado Solarmax II 90mm single stack telescope and a ZWO 183MM camera."
Solar Corona
Solar wind speed is 310.4 km/sec, with a density of 6.8 protons/cm3 at 1130 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
Since February, @ESA & @NASA’s #SolarOrbiter spacecraft has been gathering data on the Sun and the inner solar system. Now, scientists are sharing some of their early findings — including some surprises. https://t.co/PYW0sjEja5 #AGU20 pic.twitter.com/vD35DfIDsJ
— NASA Sun & Space (@NASASun) December 10, 2020
Potentially hazardous asteroids: 2037 (last updated June 2, 2020)
Total Minor Planets discovered (NASA): 1,038,961
Total Minor Planets discovered (MPC): 1,026,572
Upcoming Earth-asteroid encounters:
A couple close-passes less than 1 lunar-distance in the next couple days.
| Asteroid |
Date(UT)
|
Miss Distance
|
Velocity (km/s)
|
Diameter (m)
|
| 2018 XU3 |
2020-Dec-15
|
16.7 LD
|
10
|
30
|
| 2020 XF5 |
2020-Dec-15
|
8 LD
|
18.7
|
29
|
| 2020 XF4 |
2020-Dec-16
|
0.9 LD
|
6.8
|
11
|
| 2020 VY1 |
2020-Dec-16
|
13.2 LD
|
4.4
|
24
|
| 2020 XX3 |
2020-Dec-18
|
0.1 LD
|
5.9
|
7
|
| 2020 XF3 |
2020-Dec-18
|
18.2 LD
|
7.6
|
31
|
| 1997 XE10 |
2020-Dec-20
|
13.3 LD
|
7.2
|
36
|
| 2020 XY4 |
2020-Dec-20
|
2.1 LD
|
9.6
|
17
|
| 2017 XQ60 |
2020-Dec-21
|
10.8 LD
|
15.6
|
47
|
| 2020 XA3 |
2020-Dec-21
|
12.7 LD
|
15
|
49
|
| 2020 XJ3 |
2020-Dec-23
|
5.1 LD
|
6.2
|
28
|
| 2011 CL50 |
2020-Dec-24
|
3.1 LD
|
3.4
|
11
|
| 2020 XY |
2020-Dec-25
|
15.7 LD
|
5.7
|
26
|
| 501647 |
2020-Dec-25
|
7.9 LD
|
10
|
123
|
| 2018 XE4 |
2020-Dec-26
|
5.6 LD
|
9.4
|
19
|
| 2020 XT2 |
2020-Dec-26
|
13.1 LD
|
5.2
|
39
|
| 2012 XE133 |
2020-Dec-26
|
12.1 LD
|
9.1
|
74
|
| 2016 AF2 |
2020-Dec-27
|
7.3 LD
|
5.3
|
9
|
| 2020 XZ4 |
2020-Dec-29
|
5.4 LD
|
8.7
|
42
|
| 2012 UK171 |
2020-Dec-30
|
15.5 LD
|
4.7
|
47
|
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
On December 14, 2020, the NASA All Sky Fireball Network reported 259 fireballs!
(206 Geminids, 51 sporadics, 1 Monocerotid, 1 Leonid Minorid)
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
#Geminids were already very strong on Saturday night. Our record station logged over 750 meteors! pic.twitter.com/xHeI0sWRC6
— AMSMETEORS (@amsmeteors) December 14, 2020
If you see a bright meteor or a fireball, please REPORT IT to the American Meteor Society!
Position of the planets and several spacecraft in the inner solar system:
Position of the planets and a couple spacecraft in the inner solar system, 2020-12-15. Credit: Bob Trembley / NASA Eyes on the Solar System.
Position of the planets in the middle solar system:
Position of the planets in the middle solar system, 2020-12-15. Credit: Bob Trembley / NASA Eyes on the Solar System.
Position of the planets, some dwarf planets and some transneptunian objects in the outer solar system:
Position of the planets and some transneptunian objects in the outer solar system, 2020-12-15. Credit: Bob Trembley / NASA Eyes on the Solar System.
Solar System News
Didn't we know this several years ago?
SwRI in the news: Earth isn’t the only ocean world in the solar systemhttps://t.co/Sbg2ftLuOY
— Southwest Research Institute (@SwRI) December 14, 2020
Mars Persevere Rover:
Meet one of the many amazing members of my team. #CountdownToMars https://t.co/D6vi5CIxKB
— NASA's Perseverance Mars Rover (@NASAPersevere) December 14, 2020
International Space Station:
Cardiac research and a new toilet installation were the Monday highlights for the Exp 64 crew aboard the station. More... https://t.co/VwBPfNqFtq pic.twitter.com/GAitObHIcZ
— International Space Station (@Space_Station) December 14, 2020
Mars InSight Lander
NASA's InSight Mars lander acquired this image using its robotic arm-mounted, Instrument Deployment Camera (IDC). This image was acquired on December 5, 2020, Sol 720 where the local mean solar time for the image exposures was 14:09:36.760 PM. Each IDC image has a field of view of 45 x 45 degrees. Image Credit: NASA/JPL-Caltech
HiRISE - on the Mars Reconnaissance Orbiter:
HiPOD: Stepping It Up in Arabia Terra
Several craters in Arabia Terra are filled with layered rock, often exposed in rounded mounds. The bright layers are roughly the same thickness, giving a stair-step appearance.
More: https://t.co/6S3RIpGTl2#Mars #science pic.twitter.com/eneLtnrbog
— HiRISE: Beautiful Mars (NASA) (@HiRISE) December 15, 2020
Hubble Space Telescope #Hubble30
Today, we released new Hubble images of 30 beautiful cosmic objects from the Caldwell Catalog in honor of Hubble's 30th anniversary year! 🥳
Explore stunning galaxies, nebulae, and star clusters: https://t.co/dNXPMm8XTy#Hubble30 pic.twitter.com/Rw0MswMHGL
— Hubble (@NASAHubble) December 11, 2020
Landsat:
How did the Landsat mission go from the spark of an idea to a 50-year legacy, with 350 posters & presentations citing the mission at this year’s #AGU20 meeting alone?
Discover in Landsat 9: Continuing the Legacy, narrated by @MarcEvanJackson https://t.co/RXbNG5mOL6— NASA Landsat Program (@NASA_Landsat) December 12, 2020
Climate:
UPDATE: November 2020 was the warmest November globally since modern record-keeping began in 1880, measuring at 1.13 °C (2.03 °F) above the 1951-1980 baseline average. The 10 warmest Novembers have occurred in the past 12 years.https://t.co/AKvhatrHCO pic.twitter.com/lUL5pOIyjy
— NASA Climate (@NASAClimate) December 14, 2020
Citizen Science:
Join us! Watch #NASAScience Live this Wednesday, Dec. 16 at 3:00 p.m. EST to hear from people around the globe about how they’re doing NASA science and learn how you too can get involved with NASA’s citizen science projects.#citizenscience #DoNASAScience pic.twitter.com/mTezXoBqNd
— NASA Citizen Science (@DoNASAScience) December 14, 2020
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.
Exoplanet News
A planet found with gravitational microlensing, MOA-2013-BLG-220L b, and new transmission spectra are this week's new data.
See our news summary page for the list of tables that contain the new spectra and planetary system parameters. https://t.co/gfSUzuaG0J pic.twitter.com/1ge3SnmWVy
— NASA Exoplanet Archive (@NASAExoArchive) December 3, 2020
A gift for you: upgraded PS tables and System Overviews! 🎁🎁🎁
This bump in versions brings us one step closer to a more integrated NASA Exoplanet Archive -- and a step closer to retiring our older tables. Read the latest in our news:https://t.co/gfSUzuaG0J pic.twitter.com/cGuztP01Kk
— NASA Exoplanet Archive (@NASAExoArchive) December 10, 2020
More Dark Sky Parks!
The International Dark-Sky Association (IDA) has awarded International Dark Sky Reserve status to both the Yorkshire Dales National Park and the North York Moors National Park in northern England. https://t.co/X2HA7IWRBL
— Countryfile Magazine (@CountryfileMag) December 14, 2020
Hubble: Beautiful Universe
Caldwell 99. Credits: NASA, ESA, and R. Sahai (Jet Propulsion Laboratory); Processing: Gladys Kober (NASA/Catholic University of America)
Tour of the Local Stellar Neighborhood
Continuing with my visual tour of nearby stars and their systems, we travel to Groombridge 1618, about 15.88 light years distant.
Groombridge 1618 is 15.88 light years from Sol; the plane (green) is aligned with the orientation of the plane of the Milky Way galaxy. Credit: SpaceEngine / Bob Trembley.
Groombridge 1618
Groombridge 1618 is a star in the northern constellation Ursa Major. With an apparent visual magnitude of +6.6, it lies at or below the threshold of stars visible to the naked eye for an average observer. It is relatively close to Earth, at 15.88 light years. This is a main sequence star of spectral type K7.5 Ve, having just 67% of the Sun's mass. There is a suspected planetary companion with an orbital period of 122 days.
Properties
This star was first identified as entry 1618 in the work A Catalog of Circumpolar Stars by Stephen Groombridge published posthumously in 1838. It has such a proper motion across the sky that it guaranteed the star was quite nearby and made it an early candidate for parallax measurements. In 1884 the parallax angle was measured as 0″.322 ± 0″.023, which is larger than the modern value of 0″.205.
Groombridge 1618 has a stellar classification of K8 V, which means it is a K-type main sequence star that is generating energy by fusing hydrogen at its core. It has 67% of the mass of the Sun, 61% of the Sun's radius, but radiates only 15% of the Sun's energy and only 4.6% of the Sun's energy in the visible light spectrum. The effective surface temperature of the star's photosphere is about 4,000 K, giving it an orange hue.
It is a BY Draconis variable with a surface magnetic field strength of 750 G. The chromosphere is relatively inactive and produces star spots comparable to Sun spots. However, like UV Ceti, it has been observed to undergo increases in luminosity as a flare star.
Planetary System
A search for excess infrared emission from this star by the Infrared Space Observatory came up negative, implying that Groombridge 1618 does not possess a nearby debris disk (such as Vega does). However, observations using the Herschel Space Observatory showed a small excess suggesting a low-temperature debris disk. The data can be modeled by a ring of coarse, highly-reflective dust at a temperature below 22 K orbiting at least 51 AU from the host star. If this star does have a companion, astrometric measurements appear to place an upper bound of 3–12 times the mass of Jupiter on such a hypothetical object (for orbital periods in the range of 5–50 years).
Those observations collated by Marcy & Benitz (1989), tend towards a single notable object with periodicity of 122 days as a planetary object with minimum mass 4 times that of Jupiter. This candidate planet has not been confirmed and the signal the authors had found could have been due to intrinsic stellar activity from the star's young age. If confirmed, the planet would be within the star's habitable zone. - Wikipedia
Groombridge 1618 System Diagram
Groombridge 1618 System Diagram (Unconfirmed). Credit: Bob Trembley / SpaceEngine.
Artist Renderings of (Unconfirmed) Exoplanet Groombridge 1618 b
Artistic rendering of unconfirmed gas giant exoplanet Groombridge 1618 b seen from an asteroid moon. Credit: Bob Trembley / SpaceEngine.
Artistic rendering of red dwarf star Groombridge 1618 seen from an asteroid moon of an unconfirmed gas giant exoplanet. Credit: Bob Trembley / SpaceEngine.
What I was listening to when I was editing this:
Apologies for the tardiness of this post
One of the parrots we've owned for nearly 2 decades passed and it hit me incredibly hard.
A better pic of Orion. pic.twitter.com/LU1TMWZQvO
— AstroBalrog (@AstroBalrog) December 6, 2020
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