This Hubble Space Telescope image reveals details in the barred spiral galaxy NGC 4731.
ESA/Hubble & NASA, D. Thilker
This new image from the NASA/ESA Hubble Space Telescope shows the broad and sweeping spiral galaxy NGC 4731. It lies in the constellation Virgo and is located 43 million light-years from Earth. This highly detailed image uses data collected from six different filters. The abundance of color illustrates the galaxy’s billowing clouds of gas, dark dust bands, bright pink star-forming regions and, most obviously, the long, glowing bar with trailing arms.
Barred spiral galaxies outnumber both regular spirals and elliptical galaxies put together, numbering around 60% of all galaxies. The visible bar structure is a result of orbits of stars and gas in the galaxy lining up, forming a dense region that individual stars move in and out of over time. This is the same process that maintains a galaxy’s spiral arms, but it is somewhat more mysterious for bars: spiral galaxies seem to form bars in their centers as they mature, which helps explain the large number of bars we see today, but they can also lose them if the accumulated mass along the bar grows unstable. The orbital patterns and the gravitational interactions within a galaxy that sustain the bar also transport matter and energy into it, fueling star formation. Indeed, the observing program studying NGC 4731 seeks to investigate this flow of matter in galaxies.
Beyond the bar, the spiral arms of NGC 4731 stretch out far past the confines of this close-in Hubble view. Astronomers think the galaxy’s elongated arms are the result of gravitational interactions with other, nearby galaxies in the Virgo cluster.
June’s Night Sky Notes: Constant Companions: Circumpolar Constellations, Part III
2 min read
June’s Night Sky Notes: Constant Companions: Circumpolar Constellations, Part III
by Kat Troche of the Astronomical Society of the Pacific
In our final installment of the stars around the North Star, we look ahead to the summer months, where depending on your latitude, the items in these circumpolar constellations are nice and high. Today, we’ll discuss Cepheus, Draco, and Ursa Major. These objects can all be spotted with a medium to large-sized telescope under dark skies.
From left to right: Ursa Major, Draco, and Cepheus.
Credit: Stellarium Web
Herschel’s Garnet Star: Mu Cephei is a deep-red hypergiant known as The Garnet Star, or Erakis. While the star is not part of the constellation pattern, it sits within the constellation boundary of Cepheus, and is more than 1,000 times the size of our Sun. Like its neighbor Delta Cephei, this star is variable, but is not a reliable Cepheid variable. Rather, its brightness can vary anywhere between 3.4 to 5.1 in visible magnitude, over the course of 2-12 years.
This composite of data from NASA’s Chandra X-ray Observatory and Hubble Space Telescope gives astronomers a new look for NGC 6543, better known as the Cat’s Eye nebula. This planetary nebula represents a phase of stellar evolution that our sun may well experience several billion years from now.
Credit: X-ray: NASA/CXC/SAO; Optical: NASA/STScI
The Cat’s Eye Nebula: Labeled a planetary nebula, there are no planets to be found at the center of this object. Observations taken with NASA’s Chandra X-ray Observatory and Hubble Space Telescopes give astronomers a better understanding of this complex, potential binary star, and how its core ejected enough mass to produce the rings of dust. When searching for this object, look towards the ‘belly’ of Draco with a medium-sized telescope.
NASA’s Spitzer, Hubble, and Chandra space observatories teamed up to create this multi-wavelength view of the M82 galaxy. The lively portrait celebrates Hubble’s “sweet sixteen” birthday .X-ray data recorded by Chandra appears in blue; infrared light recorded by Spitzer appears in red; Hubble’s observations of hydrogen emission appear in orange, and the bluest visible light appears in yellow-green.
Credit: NASA, ESA, CXC, and JPL-Caltech
Bode’s Galaxy and the Cigar Galaxy: Using the arrow on the star map, look diagonal from the star Dubhe in Ursa Major. There you will find Bode’s Galaxy (Messier 81) and the Cigar Galaxy (Messier 82). Sometimes referred to as Bode’s Nebula, these two galaxies can be spotted with a small to medium-sized telescope. Bode’s Galaxy is a classic spiral shape, similar to our own Milky Way galaxy and our neighbor, Andromeda. The Cigar Galaxy, however, is known as a starburst galaxy type, known to have a high star formation rate and incredible shapes. This image composite from 2006 combines the power of three great observatories: the Hubble Space Telescope imaged hydrogen in orange, and visible light in yellow green; Chandra X-Ray Observatory portrayed X-ray in blue; Spitzer Space Telescope captured infrared light in red.
Up next, we celebrate the solstice with our upcoming mid-month article on the Night Sky Network page through NASA’s website!
Spacewalk Preps as Station Waits for Weekend Cargo and Crew Missions
The Progress 86 cargo craft, packed with trash and obsolete gear, is pictured before undocking from the space station on May 28 ending a six-month cargo mission.
The Expedition 71 crew continues gearing up for a trio of spacewalks while a cargo craft packed with food, fuel, and supplies orbits Earth headed toward the International Space Station. Back on Earth, two astronauts are counting down to their launch to the orbital lab aboard Boeing’s Starliner spacecraft.
Three NASA astronauts spent Thursday checking out a spacesuit ahead of a series of spacewalks planned to take place in June. Flight Engineer Tracy C. Dyson began her day in the Quest airlock powering up one spacesuit and checking out its life support and communications components. Afterward, she installed batteries on the suit’s jetpack, a safety device that a spacewalker would use to maneuver back to the space station in the unlikely event they became untethered from the orbital outpost.
Dyson was assisted by fellow crew members Mike Barratt and Jeanette Epps during the spacesuit checks. The duo also reviewed standard spacewalk procedures such as suiting up, exiting and entering Quest, safety steps, and communication protocols. NASA will announce the upcoming spacewalks for maintenance and science soon in a media advisory and a televised news conference.
NASA Flight Engineer Matthew Dominick started his day printing the spacewalk procedures his crewmates would later review. Next, he gathered emergency hardware and prepared the gear in advance of the arrival of two new crewmates planned to arrive on Sunday. Afterward, Dominick inspected and cleaned module hatches then set up wearable biomedical gear to monitor an astronaut’s heart activity.
Meanwhile, NASA astronauts Butch Wilmore and Suni Williams are at Kennedy Space Center in Florida preparing for their launch to the space station set for 12:25 p.m. EDT on Saturday. The duo will lift off for Boeing’s Crew Flight Test inside Starliner atop the Atlas V rocket from United Launch Alliance. The experienced crew will take a daylong ride to the space station and dock to the Harmony module’s forward port at 1:50 p.m. on Sunday.
NASA TV will broadcast the mission live on the NASA+ streaming service via the web or the NASA app. Launch and docking coverage also will air live on NASA Television, YouTube, and on the agency’s website. Learn how to stream NASA TV through a variety of platforms including social media.
In the Roscosmos segment of the station, cosmonaut Nikolai Chub continued researching the ability to 3D print tools in microgravity. Expedition 71 Commander Oleg Kononenko completed his 24-hour heart and blood pressure monitoring session then conducted a photographic inspection of windows inside the Zvezda service module. Flight Engineer Alexander Grebenkin also spent his shift inside Zvezda performing routine maintenance on the module’s air conditioning system.
NASA Welcomes Slovakia as New Artemis Accords Signatory
From left to right, Ambassador of the Slovak Republic to the United States Radovan Javorcik, Slovak Republic Minister of Education, Research, Development, and Youth Tomáš Drucker, NASA Administrator Bill Nelson, and United States Department of State Deputy Assistant Secretary for the Bureau of European and Eurasian Affairs Sonata Coulter pose for a photo during an Artemis Accords signing ceremony, Thursday, May 30, 2024, at the Mary W. Jackson NASA Headquarters building in Washington. Slovakia is the 42nd country to sign the Artemis Accords, which establish a practical set of principles to guide space exploration cooperation among nations participating in NASA’s Artemis program.
Credits: NASA/Keegan Barber
Slovakia signed the Artemis Accords Thursday during a ceremony hosted by NASA Administrator Bill Nelson at the agency’s headquarters in Washington, becoming the 42nd nation to join an international community in a commitment to peaceful, transparent, and responsible exploration of space for the benefit of all.
“NASA welcomes Slovakia as the newest signatory of the Artemis Accords,” said Nelson. “The United States and Slovakia share a deep understanding of the power of exploration. Through this new chapter in our nations’ partnership, we will further this global coalition to explore the cosmos openly, responsibly, in peace.”
Tomáš Drucker, Minister of Education, Research, Development, and Youth signed the Accords on behalf of Slovakia. Sonata Coulter, deputy assistant secretary for the Bureau of European and Eurasian Affairs, U.S. State Department, and Radovan Javorcik, ambassador of the Slovak Republic to the U.S., also participated in the signing ceremony.
“Slovakia perceives the Artemis Accords as a great opportunity for this generation to positively define guidelines and principles for the responsible and sustainable exploration and use of outer space,” said Drucker.
Earlier Thursday, Peru became the 41st country to sign the Artemis Accords. The United States and seven other nations were the first to sign the Artemis Accords in 2020, which identified an early set of principles promoting the beneficial use of space for all humanity. The accords are grounded in the Outer Space Treaty and other agreements including the Registration Convention, the Rescue and Return Agreement, as well as best practices and norms of responsible behavior that NASA and its partners have supported, including the public release of scientific data.
Several accords signatories also met face-to-face for a workshop in May to continue implementing the principles. The commitments of the Artemis Accords, and the efforts by the signatories to advance implementation of these principles, support NASA’s Artemis campaign with its partners, as well as for the success of the safe and sustainable exploration activities of the other Accords signatories.
For more information on the Artemis Accords, visit:
Planets rule the a.m., and what’s that bright light?
Saturn and Mars meet up with the Moon, Jupiter returns at dawn, and tips for identifying some common objects seen in the sky.
Highlights
All month – All the planetary action continues to be in the morning sky, with Saturn and Mars rising in the early morning hours. They are joined later in the month by Jupiter.
June 2 – In the hour before sunrise, reddish Mars hangs just beneath the crescent Moon. Find the pair low in the east with Saturn lurking nearby, toward the south.
June 3 – The crescent Moon sits beneath Mars in morning twilight. Look for them low in the eastern sky.
June 6 – New moon
June 21 – Full moon
June 24 – Jupiter is now visible low in the east before sunrise. Look for the bright planet around 10 degrees above the horizon this final week of June, forming a line with Mars and Saturn that stretches toward the south.
June 27 – Look for the Moon rising in the east with Saturn around midnight. By dawn this morning, you’ll find them high in the southern sky. They appear super close together – close enough to appear in the same field of view through binoculars.
“Planet Parade” note: Some online sources have shared excitement about a “parade of planets” visible in the morning sky in early June (June 3 in particular). In reality, only two of the six planets supposedly on display (Saturn and Mars) will actually be visible. In early June, Jupiter and Mercury will be at or below the horizon in morning twilight and not visible; Uranus and Neptune are far too faint to see without a telescope, especially as the morning sky brightens. The closest thing to a planet parade will be June 29, when Saturn, the Moon, Mars, and Jupiter will line up across the morning sky. This arrangement persists into July, and we’ll talk more about that lineup in the next “What’s Up” video.
Sky chart showing the planets’ Saturn, Mars, and Jupiter forming a diagonal line across the morning sky in late June.
Transcript
What’s Up for June? Saturn and Mars meet up with the Moon, Jupiter returns at dawn, and tips for identifying some common objects seen in the sky.
On June 2nd in the hour before sunrise, reddish Mars hangs beneath the crescent Moon. Find the pair low in the east with Saturn lurking nearby. The following morning, on June 3rd, the Moon has moved so that it sits beneath Mars.
During the last week of June, giant Jupiter re-emerges as a morning planet, after passing behind the Sun, from our point of view on Earth, over the past couple of months. By June 24th, you can find it about 10 degrees above the horizon as the morning sky begins to brighten. It climbs a little higher each morning after that as July approaches.
Then on June 27th, look for the Moon with Saturn. The pair rise around midnight, and by dawn you’ll find them high in the southern sky. They appear super close together this morning – close enough to appear in the same field of view through binoculars.
Sky chart showing the pre-dawn sky on June 3, with Saturn, Mars, and the crescent Moon.
NASA/JPL-Caltech
When you spot bright or moving objects in the night sky, it might not be immediately clear what you’re looking at. Is that a planet, or just a bright star? Is it a satellite, or maybe just an airplane? Here are a few quick tips on how to tell the difference.
First, there are five planets that are easily observed with the unaided eye. Of these, two planets – Venus and Jupiter – can sometimes appear incredibly bright, like shining beacons in the sky. The other planets are much less bright, but still generally shine as brightly as bright stars.
The big tipoff that you’re looking at a star and not a planet is that planets tend to shine steadily, whereas stars twinkle. Stars are so far away that they’re just points of light,
and ripples in our atmosphere easily distort them, causing the familiar flicker. The planets are relatively closeby, being here in our solar system. Through binoculars or a telescope, instead of a single point, planets show us a tiny disk or crescent that’s illuminated by the Sun. So even though they appear star-like to the eye, the light from a planet is coming from a slightly more spread-out area, making planets appear more constant in brightness. Both planets and stars rise in the east and set in the west, and they move very slowly across the sky during the night.
But what if you see an object that’s moving? Distant aircraft are usually pretty easy to identify, because they follow a slow, steady path that’s straight or gently curving. They have exterior lights that flash in a regular pattern, often including a red beacon.
Satellites tend to be most visible in the hour or so after dark or before dawn, when it’s night here on the surface, but the satellites are high enough in the sky to be illuminated by sunlight. They’re generally fainter than aircraft, and move in slow, very steady, very straight paths. They might briefly flare in brightness, but they don’t have lights that blink.
The International Space Station traces its path across the twilight sky over a California desert landscape.
NASA/Preston Dyches
The International Space Station is an exception, because it’s very bright, and is often visible for long enough to observe the curving path of its orbit. But it doesn’t have flashing lights you can see from the ground, and it does something else satellites do: Satellites often fade out of view as they travel into Earth’s shadow, or fade into view as they emerge. And occasionally you might see a train of satellites moving slowly and silently in formation.
One other sight that’s sometimes confusing is rocket launches that happen soon after sunset or before sunrise. Similar to spotting satellites, this is when it’s darker here on the ground, but launching rockets climb high enough to be illuminated by sunlight. When rockets launching at these times of day get really high in altitude, their exhaust can be brilliantly illuminated, and sometimes you might even see spiral or circular shapes that slowly grow and then dissipate, as a spent rocket stage empties its propellant into space.
With so much to see in the night sky, it’s helpful to be familiar with some of these common sights, so you can get on with your skywatching and investigate whatever mysteries and wonders you’re in search of.
Here are the phases of the Moon for June.
The phases of the Moon for June 2024.
NASA/JPL-Caltech
Stay up to date on NASA’s missions exploring the solar system and beyond at science.nasa.gov. I’m Preston Dyches from NASA’s Jet Propulsion Laboratory, and that’s What’s Up for this month.
