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Nova Cassiopeiae 2021 - Drops Off
July 30, 2021

Nova Cassiopeia 2021 was observed again from the Barnegat Road Observing Site in the NJ Pines on July 30, 2021, with 15x56 binoculars. It was immediately apparent that the brightness had dropped significantly compared to July 23. Compared to the stars HD 220819, mag 6.6, and HD 220057, mag 6.9, I estimated the nova at mag 7.0 to 7.5, which corresponded with values on the current light curve at AAVSO. As of this writing on Aug 4, Nova Cas 2021 is at mag 8+, comparable to the brightness after discovery in March 2021.

 

 

Nova Cassiopeiae 2021 - Brightens Again
July 23, 2021

Nova Cassiopeia 2021 was observed again from the Barnegat Road Observing Site in the NJ Pines on July 23, 2021, using a 130 mm, f/7 apo refractor with a 20 mm, 100 eyepiece (= 46x, 2.2 TFOV). With that combination, I could easily see the Nova and nearby stars HD 220819, mag 6.6, and HD 220057, mag 6.9, all at the same time. The nova appeared to be between them in brightness, which is consistent with the updated light curve shown above. The nova also displayed a mild reddish color.

This is a screen clip of the light curve generated from AAVSO data for Nova Cas through July 26 and shows visual and visual equivalent photometric magnitude estimates. The last vertical grid line on the right represents July 25 (the vertical lines are spaced at weekly intervals). Click here to see the current light curve including all wavelengths.

 

 

Nova Cassiopeiae 2021 - Outburst
May 12, 2021

Nova Cassiopeiae 2021 (V1405 Cas) experienced a sudden increase in brightness on May 6-7, 2021, as detailed by Bob King in this S&T online article. On the morning of May 11, I was able to observe it in a suburban sky through passing cirrus clouds with 15x56 binoculars (my casual magnitude estimate was 5.4). On the morning of May 12, 2021, I went to the relatively dark NJ Pines to attempt seeing it with unaided eyes. I was there from about 3:30 until 4:15 am (astronomical twilight began at 3:58 am) and passing cirrus clouds were again present, but this time, there were large gaps between the moving clouds. Using 8x42 binoculars, Nova Cas (estimated magnitude 5.6) was easy to see (as was nearby M52). I think I might have glimpsed the nova a couple of times with unaided eyes using averted vision, but they weren't certain sightings by any means.

The image above is a single raw frame captured at 3:52 am EDT using a Canon EOS RP mirrorless digital camera with a Canon 200 mm f/2.8L lens on a fixed tripod. It was exposed 2.5 seconds at f/3.2, ISO 6400. It was slightly adjusted with Canon's Digital Photo Professional 4, including cropping to about 48% of the original width and height, resulting in a field about 4.9 wide x 3.3 high. Mouseover for labels. The numbers after the star designations are the magnitudes (sans decimal point). Those in yellow are from AAVSO Chart X26520GZ, those in gray are from SkyTools.

From the mid-5 magnitude range noted above, Nova Cas continued to drop noticeably in brightness. My casual magnitude estimates were 5.9 on May 14 (at home, 15x56), 6.6 on May 15 (Swede Run, 15x56) and 7.2 on May 18 (Pines, 15x56 & 88 mm spotting scope). Update: I went to Swede Run on June 1 at 1:15 am, June 4 at 10:34 pm, June 5 at 11:30 pm and June 7 at 3:15 am; in each case using 15x56 binoculars on a monopod, I estimated Nova Cas as about magnitude 6.8. On June 10 at Carranza, using my 88 mm apo spotting scope, I estimated magnitude 6.9. As of June 11, the AAVSO visual light curve seems to have flattened at about magnitude 7 (for now).

 

 

Nova Cassiopeiae 2021
April 21, 2021

Also on the morning of April 21, 2021, while at Wharton State Forest, I checked several novae that were recently discovered when they were around eighth magnitude. They were Nova Cas 2021 (V1405 Cas), Nova Sgr 2021 (V6595 Sgr) and Nova Sco 2021 No. 2 (V1710 Sco). I had already seen Nova Cas several times from different locations using different optics, one of which is covered further down this page. This morning, April 21, it wasn't difficult to see Nova Cas and split the nova from a close ninth magnitude star using 15x56 binoculars and later, the 88 mm apo spotting scope. It appeared distinctly brighter than that star just as it did the first time I saw it. In between, it seemed to have faded such that I saw little or no difference in brightness between them. Correspondingly, the visual light curve at AAVSO shows this nova starting in the magnitude 7.5 to 8 range, then dropping to the 8 to 8.5 range, and now brightening to the 7.5 to 8 range again.

The image above includes Nova Cas and is a single raw frame captured at 3:47 am EDT on April 21 using a Canon EOS RP mirrorless digital camera with a Canon 200 mm f/2.8L lens on a fixed tripod. It was exposed 2.5 seconds at f/2.8, ISO 6400. It was slightly adjusted with Canon's Digital Photo professional 4, including cropping to about 48% of the original width and height, resulting in a field about 4.9 wide x 3.3 high. Mouseover for labels.

 

 

Nova Cassiopeiae 2021
March 22, 2021

Nova Cassiopeiae 2021, now formally designated V1405 Cassiopeiae, was discovered on March 18, 2021, as reported in this Sky & Telescope online article. Currently around eighth magnitude, it's a relatively easy target for visual observers using a small scope or binoculars, with the caveat that this circumpolar object (for 40N latitude) is reaching lower culmination on March nights. Here's a SkyTools chart. Update: Here's a AAVSO visual light curve generated on April 2, 2021.

This image, which includes the nova, was captured on March 22, 2021, from Wharton State Forest, NJ. V1405 Cas is about 6 west-northwest of Caph (Beta Cas), the second magnitude star at the western end of Cassiopeia's W-shaped stick figure. This snapshot of the area was taken at 9:14 pm EDT with a Canon EOS RP mirrorless digital camera and a Canon 200 mm f/2.8L telephoto lens on a fixed tripod. It's a single raw frame exposed 2 seconds at f/2.8, ISO 3200 and 4000 K white balance. It was mildly adjusted in Canon's Digital Photo Professional 4 and cropped to 40% of the original linear dimensions for a field 4.1 wide x 2.7 high. Mouseover for labels. At the time, the nova was at 18 altitude in the north-northwest, so it was within the Philadelphia light dome. In addition, there was a 64% illuminated moon at 71 altitude in Gemini, so the sky was relatively bright, which limited exposure. Nevertheless, all seven stars of the Little Dipper were visible with unaided eyes (albeit, the five fainter stars required some effort to see). The weather was relatively pleasant, 42F with no wind.

 

 

 

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Last Update: Thursday, August 05, 2021 at 08:21 AM Eastern Time