Bright stars and planets are splashed across the southern sky at midnight; Jupiter and Saturn are both great observing targets all night long!
Southern sky at midnight, July 4, 2018. Credit: Stellarium / Bob Trembley.Mars shines bright red in the southern sky before sunrise; Saturn sets in the southwest with the sunrise.
Mars and Saturn in the southwestern sky at 4:00 AM on July 3, 2018. Credit: Stellarium / Bob Trembley.Venus continues its vigil in the west as the evening star; you may be able to catch a glimpse of Mercury shortly after sunset.
Venus and Mercury in the western sky after sunset, July 3, 2018. Credit: Stellarium / Bob Trembley.The star Regulus will appear very near Venus after sunset on July 9th.
Conjunction of Venus and the star Regulus in the western sky after sunset, July 9, 2018. Credit: Stellarium / Bob Trembley.The Moon
The Moon is a waning gibbous heading towards third quarter on July 6th, after which it will be a waning crescent.
The Moon from July 3-July 9, 2018. Visualizations by Ernie WrightThe waning gibbous Moon will appear in the southern sky with Mars on the 3rd and 4th.
The Moon and Mars the southeastern sky at 4:00 AM on July 3, 2018. Credit: Stellarium / Bob Trembley.A thin waning crescent Moon will appear in the eastern sky with the Pleiades star cluster before sunrise on July 9th.
The Moon and Pleiades star cluster in the eastern sky at 4:00 AM on July 9, 2018. Credit: Stellarium / Bob Trembley.Observing Target: Albireo
At the head of Cygnus the swan is Albireo, a star whose name it seems, I will always spell wrong…
Location of Double Star Albireo in the constellation Cygnus. Credit: Stellarium / Bob Trembley.Albireo when viewed through a small telescope appears as a double star with a gold and a striking blue component.
Double Star Albireo, Credit: Wikipedia/Creative Commons: CC BY-SA 3.0In light-polluted skies, a trick to see the star’s colors better is to slightly de-focus the telescope:
Albireo unfocused in a small telescope. Credit: Wikipedia/Creative Commons: CC BY-SA 3.0 / Bob TrembleyIt is unknown if Albireo is a true double star system (as in the image below), or an optical binary – where the two components are not gravitationally bound, and can be physically quite far apart. If Albireo is a true binary, the pair will orbit around a common center-of-gravity called a barycenter, and have an orbital period of around 100,000 years.
Double Stars orbit around their center of mass – called a Barycenter. Credit: Space Engine / Bob Trembley.I’m hopeful stellar census data collected the GAIA mission will resolve the issue of Albireo as a binary star.
The Sun
The Sun as been spot-free for 6 days. The coronal hole at the south pole from last week seems to have closed up, only to be replaced by a large hole at the Sun’s north pole.
SpaceWeather.com says: that “the featureless solar disk is a sign that Solar Minimum is coming…” The solar wind speed is 315.4 km/sec, with a density of 10.1 protons/cm3.
To make up for the lack of sunspots, there have been small prominences everywhere on the Sun’s limb over the last couple days
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.
Asteroids
Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT)
|
Miss Distance
|
Velocity (km/s)
|
Diameter (m)
|
| 2018 LT6 |
2018-Jul-01
|
11.6 LD
|
12.9
|
126
|
| 2018 LJ1 |
2018-Jul-01
|
13.9 LD
|
2.7
|
18
|
| 2018 MB7 |
2018-Jul-04
|
2.8 LD
|
11.6
|
63
|
| 2018 LQ2 |
2018-Aug-27
|
9.4 LD
|
1.5
|
41
|
| 2016 GK135 |
2018-Aug-28
|
16.8 LD
|
2.8
|
9
|
| 2016 NF23 |
2018-Aug-29
|
13.3 LD
|
9
|
93
|
| 1998 SD9 |
2018-Aug-29
|
4.2 LD
|
10.7
|
51
|
| 2018 DE1 |
2018-Aug-30
|
15.2 LD
|
6.5
|
28
|
Notes: LD means “Lunar Distance.” 1 LD = 384,401 km, the distance between Earth and the Moon. Table from SpaceWeather.com
Near-Earth objects (NEOs) discovered this month: 0, this year: 886, all time: 18436.
Potentially hazardous asteroids: 1912 (as of July 3, 2018)
Minor Planets discovered: 779,736 (as of July 3, 2018)
Fireballs
On July 2, 2018, the NASA All Sky Fireball Network reported 27 fireballs.
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point–Earth. Source: Spaceweather.comThe Solar System
This is the position of the planets and a couple spacecraft in the solar system:
Position of the planets in the inner solar system, July 3, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets in the middle solar system, July 3, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Alternate view of the position of the planets in the inner solar system, July 3, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.As I was generating these solar system images, it occurred to me that most of the planets are (more or less) on the same side of the Sun if viewed from a certain angle along the plane of the ecliptic:
Side view of the solar system, July 3, 2018. Order from left-to right: Sun, Mercury, Venus, Earth, Mars, Neptune, Jupiter, Saturn. Credit: NASA Eyes on the Solar System / Bob Trembley.Exoplanets
Confirmed Exoplanets: 3,735 (5/31/2018)
Multi-Planet Systems: 614 (5/31/2018)
Kepler Candidate Exoplanets: 4,496 (8/31/2017)
TESS Candidate Exoplanets: 0
Data from the NASA Exoplanet Archive
Exoplanet of the Week: Kepler-16b
Kepler-16b is a Saturn-mass planet orbiting binary star Kepler-16 with a period of 229 days. Kepler-16b was the first confirmed example of a circumbinary planet– a planet orbiting a binary star pair.
Exoplanet Kepler-16bApps used for this post:
Stellarium: a free open source planetarium app for PC/MAC/Linux. It’s a great tool for planning observing sessions.
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.
Space Engine is realistic 3D space simulator; you can travel from star to star, from galaxy to galaxy
