In the Sky This Week – January 28, 2020

The handle of the “Big Dipper” asterism points nearly straight down toward the northeastern horizon at midnight this week.

The handle of the “Big Dipper” points down in the northeastern sky at midnight. Credit: Stellarium / Bob Trembley.

The waxing crescent Moon appears near at dusk on Jan 29th & 30th.

The Moon appears near the star Aldebaran at dusk on the evenings of February 2nd-4th.

Jupiter appears low and Mars appears high above the southeastern horizon at dawn this week.

Jupiter low and Mars high above the southeastern horizon at dawn this week. Credit: Stellarium / Bob Trembley.

M 47

Messier 47 (M47 or NGC 2422) is an open cluster in the constellation Puppis. It was discovered by Giovanni Batista Hodierna before 1654 and independently discovered by Charles Messier on February 19, 1771. It was later independently discovered again, under the current name NGC 2422.

There is actually no cluster in the position indicated by Messier, which he expressed in terms of its right ascension and declination with respect to the star 2 Puppis. However, if the signs of Messier’s coordinate differences are changed, the position matches that of NGC 2422. Until the equivalency of M47 with NGC 2422 was found, M47 was considered a lost Messier Object. The discovery that M47 and NGC 2422 were the same cluster only came in 1959 with a realization by Canadian astronomer T. F. Morris.

M47 is at a distance of about 1,600 light-years from Earth with an estimated age of about 78 million years. The member stars of M47 have been measured down to about red dwarfs at apparent magnitude 19. There are around 500 members, the brightest being HD 60855, a magnitude 5.7 Be star. The cluster is dominated by hot class B main sequence and giant stars, but a noticeable colour contrast comes from several bright red giants.

Location of M 47. Credit: Stellarium / Bob Trembley.

This spectacular image of the star cluster Messier 47 was taken using the Wide Field Imager camera, installed on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. This young open cluster is dominated by a sprinkling of brilliant blue stars but also contains a few contrasting red giant stars. Credit: ESO.

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

The first quarter Moon occurs on February 2nd, it will be visible high in the southern sky in early evening.

After February 2nd, the Moon will be a waxing gibbous, visible to the southeast in early evening, and up for most of the night.

The Moon from 2020-01-28 – 2020-02-03. Visualizations by Ernie Wright / NASA’s Scientific Visualization Studio.

Moon News

We have a spot! Sunspot AR2757 is a member of old Solar Cycle 24.

The northern coronal hole remains small, while the southern hole is huge!

The Sun seen in 193 angstroms (extreme ultraviolet) Jan. 27, 2020:

Some awesome prominences on the Sun’d limb over the last couple days – the location of sunspot AR2757 is easily visible as the bright orange region in the video below.

The Sun seen in 304 angstroms (extreme ultraviolet) Jan. 27, 2020:

Facebook: SolarActivity

https://www.facebook.com/photo.php?fbid=10221051272932395&set=gm.2949055088439149&type=3&theater&ifg=1

Solar Corona

Solar wind speed is 323.6 km/sec (↑), with a density of 6.3 protons/cm³ (↑) at 1257 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

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

The latest Minor Planet Center circular is out with several newly named asteroids: https://minorplanetcenter.net/iau/ECS/MPCArchive/2020/MPC_20200109.pdf

On Jan. 27, 2020, the NASA All Sky Fireball Network reported 4 fireballs. 
(3 sporadics, 1 alpha Antilid)

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 News

Position of the planets and a couple spacecraft in the inner solar system – the Parker Solar Probe will reach perihelion #4 on Jan. 29th at about 4:30 a.m. EST.

Position of the planets and a couple spacecraft in the inner solar system, 2020-01-28. 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, 2020-01-28. Credit: NASA Eyes on the Solar System / Bob Trembley.

Position of the planets in the outer solar system – the orbit of transneptunian object 148780 Altjira is highlighted:

Outer Solar System 2020-01-28 – Orbit of binary transneptunian object 148780 Altjira is highlighted. Credit: SpaceEngine / Bob Trembley.

(148780) Altjira

148780 Altjira /ælˈtʃɪrə/ is a binary classical Kuiper belt object (cubewano). The secondary, S/2007 (148780) 1, is large compared to the primary, 140 kilometres (87 mi) vs. 160 kilometres (99 mi). The Altjiran lightcurve is quite flat (Δmag<0.10), which is indicative of a "quasi-spherical body with a homogeneous surface”.

The satellite’s orbit has the following parameters: semi-major-axis, 9904 ± 56 km; period, 139.561 ± 0.047 days; eccentricity, 0.3445 ± 0.0045; and inclination, 35.19 ± 0.19°(retrograde). The total system mass is about 4 × 10¹⁸ kg.

It was named after the Arrernte creation deity, Altjira, who created the Earth during the Dreamtime and then retired to the sky.. – Wikipedia

Artist’s conception of S/2007 (148780) 1 seen in the distance from above (148780) Altj