14
$\begingroup$

This is one of the recent pictures from the James Webb released by NASA. It's a picture of the galaxy cluster SMACS 0723. It locates in the Volans constellation.

JamesWebb

I'm trying to identify the stars in this picture. For example, which star does the brightest one in the middle correspond to in the following picture of Volans constellation?

volans

$\endgroup$
7
  • 5
    $\begingroup$ I suspect that there's only one or two stars in the SMACS 0723 image collected by JWST. Those stars are the objects in the image that shows diffraction spikes. All of the other sources of light are galaxies. The paucity of nearby stars in that region of space is one of the reasons that that tiny region of space was chosen for a deep field image. $\endgroup$ Jul 15 at 4:49
  • $\begingroup$ Here is a video by Alyssa Goldman showing Zoom out from JWST image: twitter.com/AlyssaAGoodman/status/1546675001755111424 $\endgroup$
    – Elon
    Jul 16 at 1:36
  • $\begingroup$ Here is a interactive view of JWST images: web.wwtassets.org/specials/2022/jwst-release $\endgroup$
    – Elon
    Jul 16 at 2:01
  • 1
    $\begingroup$ @DavidHammen Probably more than one or two stars: nearly all diffraction spikes will be caused by (point-like) stars: nebulae and galaxies will be too fuzzy to cause spikes, except perhaps for a very compact galaxy core. $\endgroup$
    – 9769953
    Jul 16 at 21:10
  • $\begingroup$ I think if you type SMACS 0723 here : aladin.u-strasbg.fr/AladinLite you can choose your favorite survey to view its vicinity. $\endgroup$
    – chris
    Jul 17 at 16:11

3 Answers 3

18
$\begingroup$

None of the stars in the image of SMACS 0723 are bright enough to be shown in the picture you've provided of Volans.

SMACS 0723's at right ascension 07h 23m 19.5s, declination -73° 27′ 15.6”, and the image is approximately 2.4 arcminutes across, according to "Webb’s First Deep Field: Galaxy Cluster SMACS 0723" from constellationguide.com.

The view field of the SMACS 0723 image is too small, and the stars within it aren't bright enough to be among the stars that are in the image you've provided.

Stellarium Location and Stars

My version of Stellarium locates the object at a slightly different position, but with the brightness minimums set to magnitude 5.7, and field of view of 11.7° no stars in my attempt at approximation of your provided image are nearby enough to appear in the JWST image.

(My personal version of Stellarium doesn't show any stars at all close enough to the location to appear in the image even when I kick the brightness limits down to magnitude 12. I don't have enough information in my Stellarium install to definitively identify any of the potential stars in the JWST deep-field image.)

$\endgroup$
4
  • 2
    $\begingroup$ In contrast, the Volans constellation is about 12 degrees across, or about 300 times wider than the SMACS 0723 image. $\endgroup$ Jul 15 at 4:45
  • 5
    $\begingroup$ With regard to the edit, "no stars in my attempt at approximation of your provided image are nearby enough to appear in the JWST image." That's the intent of a deep field image. A star with an even moderately low apparent magnitude would ruin the deep field image. While there is obviously at least one star in the JWST deep field image, I strongly suspect it is a star with such a ridiculously low apparent magnitude that Stellarium doesn't bother to model it. $\endgroup$ Jul 15 at 10:50
  • $\begingroup$ This answers the question and does so well, but I'm still hoping someone with a beefier data set can identify the star even though Stellarium doesn't. $\endgroup$
    – Bear
    Jul 15 at 13:07
  • $\begingroup$ @Bear - one thing, the only "identification" of such a star would likely just be some database entry (likely from GAIA). $\endgroup$
    – Fattie
    Jul 16 at 17:31
12
$\begingroup$

Notovnys answer does explain where one can find the picture. Stellarium web does indeed show stars with a lower magnitude if one zooms in.

At 07h 23m33.2s, -73°27'22.2", which puts it close to the center of the image, one can find the star Gaia DR2 5262905967918434432 with a magnitude of 15.81. One can only see its position in this pictue:

enter image description here

If one zooms in a lot one can finally see this 0.04 Degree should be almost the same as the 2.4 arcminutes mentioned in the other answer:

enter image description here

$\endgroup$
3
  • 1
    $\begingroup$ Ah, interesting .I guess the web version was bound to be more up-to-date than my desktop version, which I hadn't updated in a couple years, and probably hadn't downloaded any packages with stars that dim. $\endgroup$
    – notovny
    Jul 15 at 16:52
  • 1
    $\begingroup$ Darn, I guessed it was 5262905967918434431 or maybe 5262905967918434437. Who would have thought 5262905967918434432 ? Obvious in retrospect. $\endgroup$
    – Fattie
    Jul 16 at 17:31
  • 1
    $\begingroup$ I exhaled through my nose @Fattie :) $\endgroup$
    – SirHawrk
    Jul 17 at 5:52
8
$\begingroup$

I don't have astronomy experience, but since I took the time to identify the star, I thought I would post it here. I simultaneously zoomed in the provided links https://web.wwtassets.org/specials/2022/jwst-release/ and https://stellarium-web.org/ and found the exact star which is Gaia DR2 5262900027979791104. It has a magnitude of 14.56 and is at 07h 22m 47.9s, -73°29'26.5" on Stellarium Web.

As other answers have stated, the star is not visible on the picture showing Volans as it is very faint. It can only be seen after zooming in many times on Stellarium Web.

The Gaia Data Release at https://gea.esac.esa.int/archive/ says that the same star is at right ascension 7h 23m 18.3s and declination -73°26'55.4" after unit conversion, which is closer to the stated position of SMACS 0723.

Stellarium Web screenshot AAS WorldWide Telescope screenshot

Side by side view for original image Side by side view

Location near Volans Stellarium Web screenshot of Volans

The nearest star I could link is here. https://stellarium-web.org/skysource/TYC9191-737-1?fov=0.14092&date=2022-07-17T16:40:00Z&lat=39.93&lng=-116.32&elev=0 The website should look like the image below after disabling Atmosphere and Landscape at the bottom of the screen. I have marked the red square which is the JWST image location, and the red cross which is the position of SMACS 0723 given by many sources at 07h 23m 19.5s, -73° 27′ 15.6”. Marked Stellarium Web screenshot

$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .