The LONG period(?) comet C/2022 E3 (ZTF) is predicted to become visible to the naked eye in late January - early February. ST4v currently estimates the brightness at 7.1 magnitude in Corona Borealis in the morning. Some estimates have the period as ~50,000 years. The NASA JPL Small Body Database lookup page lists the eccentricty (e) as 1.000270488706647±7.7609E-7, so a slightly hyperbolic orbit & not really periodic.
Here's ST4v's description of the naked eye visibility of the comet:
"C/2022 E3 (ZTF) will reach perihelion in mid January. On January 12 this comet will pass within 0.3 AU of the earth. It is predicted to reach maximum brightness of magnitude 5 in late January. The best visibility from Darby Creek 2 near maximum brightness is predicted to be in late January when it will be approximately magnitude 5. On February 1 this comet will be moving quickly across the sky at a peak rate of 16.6 "/min PA 211.2°. Note that future predictions of magnitude and visibility are subject to the unpredictable nature of these objects."
This is a northern hemisphere object as it will pass through Draco & Ursa Minor. Information about this comet is in the Current Comets Observing List for 2023 January.
The Minor Planet Center (MPC) has reported the first 2 MPs of 2023, the NEOs 2023 AA & 2023 AB. Neither one was listed as approaching within 0.05 AU on the CNEOS website.
It uses a cluster of 30cm telescopes & special software that looks similar to the Tycho Tracker software that can stack signals from moving objects to gain the benefits of multiple exposures to increase SNR.
This large NEO (0-1 km) is predicted to make a close approach during early February 2023. ST4v predicts that this object will reach a peak brightness of 13.4 magnitude on 2023 Feb 14 when it will be in Antlia moving at 39.7"/min.
This will be a good object for southern hemisphere observers. I'll post more information closer to the end of January.
This is not an especially close pass, but because of its size and well known orbit, thought I would mention it. Using the Horizons osculating elements for Feb 2, I ran an ephem for the 4.7LD pass 2023-Feb-03 08:51UT. From my location, it is near 15th magnitude fairly high in my SE light polluted sky moving ~1'/min.
The interesting point is that it is much higher and brighter (14.4) on Feb 1 @03:00CST moving thru Sextans and then again high and bright on the Crater/Virgo/Corvus border, next day, same time. This is due to phase angle improvement.
The big rock continues back into Virgo as it dips below my horizon and fades as the phase angle plummets. Then back up in the predawn of close pass on the 3rd but dim. Track below.
Is there a way to customize the sky mag limit for each telescope from each location? For instance from home, I observe with my 13" from generally Bortle 4 skies. The issue is that when looking south, I'm limited by a dome of sky fog (light pollution) from local towns and cities. Looking for a way to change my limits in that zone.
I'm testing the Exposure Calculator Tool, and I'm not sure if it is working correctly. I'm comparing my real results with the calculated results. So far they are not even close to each other, despite being sure that all the settings are correct.
In addition, my understanding is that if I increase the gain of my camera, then the required time to reach a certain SNR value will be shorter, but using the tool, the total exposure time does NOT change for ALL the gain values that I have! Is this reasonable? Attached is a sample for a target where the required time is 28 minutes to reach SNR value of 50 for ALL the gain values!
Also, I have a question regarding the "Read Noise" value that I should enter for my camera, is it the minimum or the maximum or the value which corresponds to my gain value? The same question applies if I'm doing BIN2, then should I keep the value for BIN1 and the tool will convert it? Or should I enter the value of BIN2?
Researchers from NASA and the University of Alaska are about to perform an unusual radar experiment. They’re going to ping a near-Earth asteroid using shortwave radio. The target is a 500-ft-wide space rock named “2010 XC15.” When it passes by Earth on Tuesday, Dec. 27th, the HAARP array in Alaska will hit it with a pulse of 9.6 MHz radio waves.
What’s unusual about this experiment is the frequency: 9.6 MHz is hundreds of times lower than typical S-band and X-band frequencies used by other asteroid radars. The goal is to probe the asteroid’s interior.
