Tag Archives: Scope Mob

An Update On Nova Del 2013 (PNVJ20233073+2046041) – Dimmer Views And A Distance Estimate

Greetings fellow astrophiles!

While the Night Sky is always inspiring, it is quite… constant. The positions of objects within our own Solar System change with respect to the background of stars, weather patterns on Jupiter and Saturn can produce a bit of variety for backyard telescopes, Iridium flares and other satellites produce some nice bursts of reflected sunlight, the Sun can prove to be a many-varied treat to afternoon solar watchers, and the most astute observers can pick out the differences in brightness of variable stars. That said, much of the rest of the Night Sky only changes due to the rotation of the Earth about its axis and the revolution of the Earth around the Sun (within the lifetimes of most observers, that is).

Significant changes to stars, nebulae, and galaxies can take decades, lifetimes, or eons, meaning even many observers take in the same deep sky views throughout their entire lives. The recent nova in Delphinus was then noteworthy as something that (1) changed dramatically over the course of days and (2) occurred within our own Milky Way galaxy. CNYO members held their first Scope Mob at Jamesville Beach to take in a prime view of the nova from just outside Syracuse, finding a quite reasonable spot for future sessions at the same time.

2013sept14_gif_1531x1459_2db958_zps3f68f105

“Animation of Possible Nova in Del by E. Guido & N. Howes,”
taken from s176.photobucket.com/…/gif_1531x1459_2db958_zps3f68f105.gif.html

With several excellent websites providing great detail on the nova itself (I specifically direct you to universetoday.com, space.com, and AstroBob’s article (link HERE), which I count as the most thorough article written on the event), a group of astronomers have provided an official measurement of the distance to Nova Del 2013, posted to Astronomers Telegram on 23 August. In their report, they determine that the nova is 4.2 kiloparsecs (I refer you to the wikipedia article on the parsec for more info), or about 13,700 light years, away. As our own galaxy is about 100,000 light years across and we’re about 25,000 light years from the center, this puts the nova in our own celestial neighborhood. That said, this means the nova itself occurred near the end of Beringia, the land at the bottom of the Bering Strait, after the last great ice retreat but before the flooding that separated Asia from America (so it’s been a while, but an eye blink in celestial terms).

A snippet of the abstract that includes the reported distance estimate is reproduced below from the original post, which can be found at: www.astronomerstelegram.org/?read=5313

Distance of nova Del 2013 from MMRD relations

ATel #5313; M. M.M. Santangelo, M. Pasquini, S. Gambogi, G. Cavalletti (OAC – Osservatorio Astronomico di Capannori and IRF – Istituto Ricerche Fotometriche, Italy)
on 23 Aug 2013; 15:56 UT
Credential Certification: Filippo Mannucci (filippo@arcetri.astro.it)

Subjects: Optical, Nova

… So the distance of the nova is d ~ 4.2 +/- 0.4 kpc Using the linear Mv-log(t2) relation of Downes & Duerbeck (2000, AJ 120, p.2007) a t2 = 8.5 implies an absolute magnitude of Mv ~ -8.9 +/- 0.2. So, ceteris paribus, the distance changes to d ~ 3.5 +/- 0.4 kpc. As a final preliminary estimate, we can adopt a value around 4 kpc (or a bit less) for the distance of the nova DEL 2013.

A Small Mob For A Big Event – Quick Summary Of The New Nova Party For PNVJ20233073+2046041

CNYO’s first official “Scope Mob” and New Nova Party was composed of Larry Slosberg, Dan Williams, and myself. After only 50 minutes of observing (and enjoying a moonlit sky still clear enough to see plenty of detail), I am pleased to report that we:

(1) found the nova easily enough in binoculars and scopes

(2) saw three bright Perseids between us (it’s still going!)

(3) caught the ISS and many, many satellites

(4) as an added bonus – we caught DAICHI (ALOS) that flared four times as it went from South to North (very nice addition!). To see what gave it that flaring power, I refer you to the image below (and its very hefty solar array):

2013august15_jaxa-alos-daichi-satellite

DAICHI (ALOS) – See space.com for details.

(5) found the Moon yet again (very pleasant as always, with some nice brightening of high-elevation objects beyond the terminator)

(6) found a great little spot for hosting future impromptu darker sky observing sessions

For those wanting to check out the nova themselves in the next few days, I am pleased to report that it is presently Naked Eye (so is markedly brighter than it was even last night – 5.0 and brightening by all reports). For those interested in the search, I provide unlabeled and labeled images below. The key is to find the brighter Delphinus (look below Cygnus for the medium-bright diamond shape), then find Sagitta above and to the right (looks like a dim arrow). Naked Eye, you will see a star above Delphinus’ head, then another one between this bright star and the arrow tip of Sagitta. That “other” star is the nova, likely set to be even brighter tomorrow (with a closer Moon but still clear predicted skies). If you’re using 7x to 25x binoculars, you will see a small cluster of stars to the lower-left of the nova – which I’ve connected in the form of a Rockette for what may or may not be an obvious reason.

2013august15_nova_unmarked

Unmarked image (Canon T3i, 13 sec. exposure, ISO 1600). Click for a larger view.

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Marked image (Canon T3i, 13 sec. exposure, ISO 1600). Click for a larger view.

But it’s a relatively easy find once you have Delphinus and Sagitta figured out. There are only two other bright starts in the vicinity!