#hd 107146

[chibinotan]

Vermin Galaxy and Milky Way Star

[wigmund]

From SpaceTelescope.Org Picture of the Week; May 29, 2017:

Viewing the Vermin Galaxy

The NASA/ESA Hubble Space Telescope is famous for its jaw-dropping snapshots of the cosmos. At first glance this Picture of the Week appears to be quite the opposite, showing just a blur of jagged spikes, speckled noise, and weird, clashing colours — but once you know what you are looking at, images like this one are no less breathtaking.

This shows a distant galaxy — visible as the smudge to the lower right — as it begins to align with and pass behind a star sitting nearer to us within the Milky Way. This is an event known as a transit. The star is called HD 107146, and it sits at the centre of the frame. Its light has been blocked in this image to make its immediate surroundings and the faint galaxy visible — the position of the star is marked with a green circle.

The concentric orange circle surrounding HD 107146 is a circumstellar disc — a disc of debris orbiting the star. In the case of HD 107146 we see the disc face-on. As this star very much resembles our Sun, it is an interesting scientific target to study: its circumstellar disc could be analogous to the asteroids in our Solar System and the Kuiper belt.

A detailed study of this system is possible because of the much more distant galaxy — nicknamed the “Vermin Galaxy” by some to reflect their annoyance at its presence — as the star passes in front of it. The unusual pairing was first observed in 2004 by Hubble’s Advanced Camera for Surveys, and again in 2011 by Hubble’s Space Telescope Imaging Spectrograph. The latter image is shown here, as the Vermin Galaxy began its transit behind HD 107146. The galaxy will not be fully obscured until around 2020, but interesting science can be done even while the galaxy is only partly obscured. Light from the galaxy will pass through the star’s debris discs before reaching our telescopes, allowing us to study the properties of the light and how it changes, and thus infer the characteristics of the disc itself.

Credit: ESA/Hubble & NASA

[alxndrasplace]

(NASA)  Hubble "Traps" a Vermin Galaxy

Image credit: ESA/Hubble & NASA

(...) This (image) shows a distant galaxy — visible as the smudge to the lower right — as it begins to align with and pass behind a star sitting nearer to us within the Milky Way. This is an event known as a transit. The star is called HD 107146, and it sits at the center of the frame. Its light has been blocked in this image to make its immediate surroundings and the faint galaxy visible — the position of the star is marked with a green circle.

The concentric orange circle surrounding HD 107146 is a circumstellar disk — a disk of debris orbiting the star. In the case of HD 107146 we see the disk face-on. As this star very much resembles our sun, it is an interesting scientific target to study: its circumstellar disk could be analogous to the asteroids in our Solar System and the Kuiper belt.

Full article here

[kosmos-x]

Космический телескоп «Хаббл» увидел «галактику-паразита»

Космический телескоп «Хаббл» известен своими потрясающими снимками космоса. Поэтому представленно... Читать дальше »

[astroblogs]

Zwerm van "Pluto's" ontdekt bij een zon-achtige ster?

ALMA image of the dust surrounding the star HD 107146. Dust in the outer reaches of the disk is thicker than in the inner regions, suggesting that a swarm of Pluto-size planetesimals is causing smaller objects to smash together. The dark ring-like structure in the middle portion of the disk may be evidence of a gap where a planet is sweeping its orbit clear of dust.

Astronomen hebben mogelijk bewijs gevonden voor een hele familie van Pluto-achtige dwergplaneten rondom een jongere versie van de zon. Men heeft namelijk gedetailleerde waarnemingen verricht bij de stofschijf rondom de zonachtige ster HD 107146. Tot ieders verbazing bleek de dichtheid van de schijf het hoogst te zijn aan de rand, m.a.w. op grote afstand van de moederster (zo’n 13 miljard kilometer). Dit zou het gevolg kunnen zijn van Pluto-achtige dwergplaneten die door de buitenschijf bewegen en de boel danig verstoren, waardoor kleinere objecten massaal op elkaar klappen en uiteen geblazen worden.

Artist impression of the debris disk around HD 107146. This adolescent star system shows signs that in its outer reaches, swarms of Pluto-size objects are jostling nearby smaller objects, causing them to collide and “kick up” considerable dust.

Daarnaast hebben de waarnemingen, die overigens verricht zijn door ALMA, ook mogelijk bewijs gevonden voor een gat in de stofschijf op een afstand van ongeveer 2,5 keer de afstand tussen Neptunus en de zon. Dit “gat”, eigenlijk een “depressie” in het aantal stofdeeltjes, zou mogelijk veroorzaakt kunnen zijn door planeet van ongeveer een aardemassa die z’n omloopbaan aan het schoonvegen is. Dat zou betekenen dat planeten ter grootte van de aarde op een geheel nieuwe plaats gevonden kunnen worden: ver in de buitendelen van een planetenstelsel!

Bron: National Radio Astronomy Observatory

Astroblogs: http://www.astroblogs.nl/2014/12/12/zwerm-van-plutos-ontdekt-bij-een-zon-achtige-ster/