Saturn and Jupiter are excellent observing targets all week after sunset – Jupiter is getting lower towards the horizon each evening. I’m also noting that it’s getting darker earlier each evening.
Saturn and Jupiter in the southwestern sky after sunset on Oct. 15, 2019. Credit: Stellarium / Bob TrembleyThe Moon appears in the predawn sky this week, moving from west to east; the waning gibbous Moon appears high in the western sky before sunrise on Oct. 15 & 16th.
The waning gibbous Moon high in the western sky before sunrise on Oct. 15 & 16th. Credit: Stellarium / Bob TrembleyOn Oct. 17 and 18th, the waning gibbous Moon appears near the star Aldebaran in the southwestern predawn sky.
The third-quarter Moon appears high in the southern predawn sky near the star Pollux on Oct. 21st.
The thrid-quarter Moon high in the southern sky on Oct. 21, 2019. Credit: Stellarium / Bob TrembleyMars appears low in the eastern sky just before sunrise.
The planet Mars appears low on the eastern horizon before dawn. Credit: Stellarium / Bob TrembleyOrion was again impossible to miss high in the southern predawn sky.
The constellation Orion, high in the southern predawn sky. Credit: Stellarium / Bob Trembley
Betelgeuse
Betelgeuse is generally the ninth-brightest star in the night sky and second-brightest in the constellation of Orion (after Rigel). It is a distinctly reddish, semiregular variable star whose apparent magnitude varies between +0.0 and +1.3, the widest range of any first-magnitude star. At near-infrared wavelengths, Betelgeuse is the brightest star in the night sky. It has the Bayer designation α Orionis, which is Latinised to Alpha Orionis and abbreviated Alpha Ori or α Ori.
Classified as a red supergiant of spectral type M1-2, Betelgeuse is one of the largest stars visible to the naked eye. If Betelgeuse were at the center of the Solar System, its surface would extend past the asteroid belt, engulfing the orbits of Mercury, Venus, Earth, Mars, and possibly Jupiter. However, there are several other red supergiants in the Milky Way that are larger, such as Mu Cephei and VY Canis Majoris. Calculations of its mass range from slightly under ten to a little over twenty times that of the Sun. It is calculated to be 640 light-years away, yielding an absolute magnitude of about −6. Less than 10 million years old, Betelgeuse has evolved rapidly because of its high mass. Having been ejected from its birthplace in the Orion OB1 Association—which includes the stars in Orion’s Belt—this runaway star has been observed moving through the interstellar medium at a speed of 30 km/s, creating a bow shock over four light-years wide. Betelgeuse is in the last stages of its evolution, and it is expected to explode as a supernova within the next million years. – Wikipedia
This is the first direct image of a star other than the Sun, made with the Hubble Space Telescope. Called Alpha Orionis, or Betelgeuse, it is a red supergiant star marking the shoulder of the winter constellation Orion the Hunter. The Hubble image reveals a huge ultraviolet atmosphere with a mysterious hot spot on the stellar behemoth’s surface. The enormous bright spot, more than ten times the diameter of Earth, is at least 2, 000 Kelvin degrees hotter than the surface of the star. Credit: Andrea Dupree (Harvard-Smithsonian CfA), Ronald Gilliland (STScI), NASA and ESA
Deep-sky objects in the constellation Orion. Credit: Stellarium / Bob Trembley
The Moon will be a waning gibbous, rising after sunset, visible high in the sky after midnight, and visible to the southwest after sunrise.
The third-quarter Moon occurs on October 21st, rising around midnight, and visible to the south after sunrise.
The Moon from Oct. 15-21, 2019. Visualizations by Ernie Wright / NASA’s Scientific Visualization Studio.
The sun has been spotless for 12 days; coronal holes appear at both poles – with a tendril stretching up towards the equator from the south pole.
Sun in 193 angstroms (extreme ultraviolet) Oct. 15, 2019. Image courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.[Link to 48-hour video of the Sun in 193 angstroms]
Some impressive prominences on the Sun’s limb! I enlarged a couple below.
Sun in 304 angstroms (extreme ultraviolet) Oct. 15, 2019. Image courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
Prominences on the Sun – Oct. 15 2019 see in 304 Angstroms. Image courtesy of NASA/SDO and the AIA, EVE, and HMI science teams, edited by Bob Trembley.[Link to 48-hour video of the Sun in 304 angstroms]
https://www.facebook.com/photo.php?fbid=10218022835596203&set=gm.2713166918694635&type=3&theater&ifg=1
The solar wind speed is 361.4 km/sec (↓), with a density of 2.8 protons/cm3 (↑) at 1342 UT.
Animated LASCO C2 Coronograph showing the solar corona above the Sun’s limb (the white circle). Credit: NASA/JPL-CaltechYou 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.
Sun News
Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT)
|
Miss Distance
|
Velocity (km/s)
|
Diameter (m)
|
| 2019 SR8 |
2019-Oct-16
|
13.5 LD
|
9.8
|
26
|
| 2019 TE2 |
2019-Oct-18
|
8.2 LD
|
10.1
|
29
|
| 2019 TW6 |
2019-Oct-18
|
14.8 LD
|
5.6
|
19
|
| 2019 TP5 |
2019-Oct-18
|
8.2 LD
|
18.6
|
29
|
| 2019 TA1 |
2019-Oct-18
|
15.5 LD
|
6.4
|
22
|
| 2019 TM7 |
2019-Oct-18
|
10.9 LD
|
23.8
|
57
|
| 2019 TK5 |
2019-Oct-19
|
2.5 LD
|
5.8
|
11
|
| 2019 TG7 |
2019-Oct-19
|
16.8 LD
|
7.6
|
23
|
| 2019 SJ8 |
2019-Oct-19
|
11.6 LD
|
7.4
|
48
|
| 2019 TQ2 |
2019-Oct-25
|
12.8 LD
|
12.4
|
35
|
| 162082 |
2019-Oct-25
|
16.2 LD
|
11.2
|
589
|
| 2017 TG5 |
2019-Oct-25
|
14.4 LD
|
11.9
|
34
|
| 2019 TR2 |
2019-Oct-29
|
19.4 LD
|
13.9
|
73
|
| 2015 JD1 |
2019-Nov-03
|
12.9 LD
|
11.9
|
269
|
| 2010 JG |
2019-Nov-12
|
19.6 LD
|
14.9
|
235
|
| 481394 |
2019-Nov-21
|
11.3 LD
|
7.9
|
372
|
| 2008 EA9 |
2019-Nov-23
|
10.5 LD
|
2.2
|
10
|
| 2017 AP4 |
2019-Dec-03
|
8.5 LD
|
7.5
|
15
|
| 2018 XW2 |
2019-Dec-07
|
17.4 LD
|
13
|
28
|
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
Potentially hazardous asteroids: 2018 (last updated Oct. 1, 2019)
Minor Planets discovered: 829,334 (+588)
Asteroid News
On Oct. 14, 2019, the NASA All Sky Fireball Network reported 8 fireballs.
(8 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.comFireball News
Comet C/2019 Q4
Position of the planets and a couple spacecraft in the inner solar system:
Position of the planets and some spacecraft in the inner solar system, Oct. 15 2019 – the orbit of asteroid 101955 Bennu is highlighted. Credit: NASA Eyes on the Solar System / Bob Trembley.Position of the planets and a couple bodies in the middle solar system:
Position of the planets in the middle solar system, Oct. 15, 2019. Credit: NASA Eyes on the Solar System / Bob TrembleyPosition of the planets and a several bodies in the outer solar system:
Position of the planets in the outer solar system, Oct. 15, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley2014 UZ224 a trans-neptunian object (TNO) and possible dwarf planet orbiting in the scattered disc. As of October 2018, it was approximately 90.7 astronomical units (1.357×1010 km) from the Sun, and will slowly decrease in distance until it reaches its perihelion of 38 AU sometime near 2142. The discoverers have nicknamed it “DeeDee” for “Distant Dwarf”.
2014 UZ224 was discovered by a team led by David Gerdes using data collected by the large camera Dark Energy Camera (DECam). It has a diameter of ~635 km (395 mi) and reflects just 13 percent of the sunlight that hits it on its 1,136 year orbit around the sun. Since the numbering of (532037) 2013 FY27 in May 2019, 2014 UZ224 is the largest unnumbered object in the Solar System. –Wikipedia
Orbit of Trans-neptunian object 2014 UZ224 – Oct. 15, 2019. Credit: SpaceEngine / Bob Trembley
