Our minimal contribution appeared here!. International Churyumov readings “CAMMAC-2020”.
THE DISINTEGRATIONS OF COMETATLAS BY OBSERVATIONS IN TAJIKISTAN AND INDIA:
G.I.Kokhirova1, О.V.Ivanova2,3,4, F.Dzh.Rakhmatullaeva1,S.Borysenko3, V.K.Agnihotri5, A.M. Buriev1.1. Institute of Astrophysics of the National Academy of Sciences of Tajikistan,2. Astronomical Institute of the Slovak Academy of Sciences,3. Main astronomical observatory of the National Academy of Sciences of Ukraine,4. Astronomical Observatory named after T. ShevchenkoKyiv National University5. Cepheid Observatory, Rawabhata Via Kota,Raj, India
Long-period comet C/2019Y4 (Atlas) discovered 28 on December 2019, has passed the perihelion on May 31, 2020.At the end of March 2020, observations by the Hubble Space Telescope were registered the disintegrations ofthe comet’s nucleus into several fragments. To study the nuclear fragmentation observations of comet C/2019Y4(Atlas)in the Cepheid Observatory of India, the International Astronomical Observatory Sanglokh (IAOS)and the Hissar Astronomical Observatory (HissAO) of the Institute of Astrophysics of the National Academy of Science of Tajikistanwere out carried in March-April 2020.Some physical properties of the main nucleus fragment were evaluated using the photometric measurements of comet images.These data confirm the disintegrations of the comet’s nucleus. The coordinates of the comet were determined, the orbit was calculated.and it was shown that the disintegration of the nucleus did not affect the stability of the orbit of the main.Key words: comet, photometry, light curve, astrometry, nucleus, coordinates, orbit. Page35/36 https://cammac.univ.kiev.ua/book-of-abstracts
In March of 2021 I reached out to the Cepheid Observatory team (V.K.Agnihotri, B. Kumar, S. Mahawar, K.Vora) requesting an imaging run on asteroid Apophis. I was impressed by their effort to obtain that data, which I will use in teaching a class on Asteroid studies.
The follow on lightcurve study they performed on the data is quite interesting and is indicative of the scientific rigor of their work
Asteroid research is conducted by a small community of highly dedicated astronomers. I for one greatly appreciate the opportunity to work together with my fellow researchers on the other side of our pale blue dot. I am only just beginning my collaboration with this team of bright thinkers, and look forward to working with them in the future! Please accept my thanks for your assistance!
Jerry Hilburn(San Diego California, USA)– He is working at catfish Software Inc. and also an amateur astronomer. He is contributor in many papers on Astrometric and Photometric Measurements of double stars. For more visit:http://jdso.org/
Asteroid photometry is nothing but the study of fraction of solar radiation, which is reflected by the surface of small body. Here we examined the photometry of Apophis, a big/elongate metal rich asteroid passing by near to earth.
If we assume that asteroid Apophis is metal rich, it could reflect good part of solar radiation at V band as well as R Band. The tendency of photon reflection decrease from V (short wavelengths) to R (longer wavelengths) band. Here we took the assumption that sun is G2V type star, so most of photons are towards yellow + red end and hence small body is reflecting more photons at R band. These are just assumption to make task interesting. Anyway!
The second point is that if asteroid is perfect spherical body, spinning around random axis will reflect same flux towards telescope, but case will be different if small body have irregular structure. In this case the flux reflected will be proportional to the cosine of area seen by telescope and depend on angle between sun/asteroid/earth.
In our study, we dragged the R band flux w.r.t time. The FITS generated and examined using PriSMv10 batch photometry using UCAC4 catalog. The results are shown below.
We should not forget that Apophis photometric curve was measured w.r.t standard stars and as soon as sun and asteroid changes the position in sky, the incident solar flux does not remain constant. It can be seen that the magnitude at the end of observation goes too high.
Instrument: Catalog: UCAC4 Bessell (B): +*.*, Bessell (V): +*.* Bessell (R): +15.2, Bessell (I): +*.* CCD: ATIK-383L+ FILTERS: R TELESCOPE: C11, 1623.0mm PRiSMv10, Astrometrica Site: ORIGIN: Cepheid Observatory, India, Vorion Scientific, India SITELAT: +24:55:00:00 SITELONG:+75:33:58:99 Observers: V.K.Agnihotri, B. Kumar, S. Mahawar, K.Vora Remark: Sky Clear. End
“I must say, Cepheid Observatory is one of the upcoming observatories to rock the world. The detailed information provided in the website enhances the zeal in me to learn more about Astronomy. The explained procedures of astronomical astrometry, photometry and spectroscopy , develops a sense of scientific revolution in the youth. Hoping for the best times with Cepheid Observatory.
“Thank you “
Khushi Arora (India)– She is currently doing graduation in scienceand want to be an astrophysicist and start an experimental laboratory of astrochemistry in India. She is an amateur astronomer and a motivational speaker . She is working as a citizen scientist and space educator.
Apophis is 1,120 feet (340-meter-wide) wide and made of rock, iron and nickel. It is probably shaped roughly like a peanut, though astronomers will have a better idea of its form when it passes by Earth this week, according to NASA.
The asteroid takes a full orbit around the sun about every 11 months. On March 5, it will come within 10,471,577 miles (16,852,369 km) of Earth at 8:15 p.m. EST (0115 GMT on March 6). That’s too far to be seen with the naked eye, but scientists will use planetary radar to image Apophis as it flies by using NASA’s Goldstone Deep Space Communications Complex in California and the Green Bank Telescope in West Virginia. They hope to determine the asteroid’s shape and learn more about the way it rotates.
“We know Apophis is in a very complicated spin state, it’s sort of spinning and tumbling at the same time,” Richard Binzel, a planetary scientist at the Massachusetts Institute of Technology, told Space.com.
Instrument: Catalog: MPC Bessell (B): +*.*, Bessell (V): +*.* Bessell (R): +15.2, Bessell (I): +*.* CCD: ATIK-383L+ FILTERS: R TELESCOPE: C11, 1623.0mm PRiSMv10, Astrometrica Site: ORIGIN: Cepheid Observatory, India, Vorion Scientific, India SITELAT: +24:55:00:00 SITELONG:+75:33:58:99 Observers: V.K.Agnihotri, B. Kumar, S. Mahawar, K.Vora Remark: Sky Clear. End
QSO 0957+561 is first discovered gravitational lens system by Walsh, Carswell, & Weymann in 1979. The quasar QSO 0957+561 appears twin (QSO 0957+561A and QSO 0957+561B) due to gravitational lensing by host galaxy YGKOW G1 that is located directly between Earth and the quasar. The expected distance of QSO 0957+561 from earth is around 9.0 billion Ly.
The photometric analysis of such lensed quasars a like QSO 0957+561 are studied to estimate the more accurate value of Hubble constant. Two images are photometrically examined for long time to estimate the time delay which is proportional to difference between distances travelled by to twin counterparts and mass lens model (which depends on host galaxy). The time delay approach is independent of both methods, like plank ΛCDM (Lambda cold dark matter) or Lambda-CDM model flat results and distance ladder + Type Ia SNe results, which are previously used to estimate Hubble constant (for more watch video link added below).
We imaged the QSO 0957+561A and QSO 0957+561B. An astrometric reduction of two optical centers of twin quasars in FITS image estimates the separation of 6 arc second due to gravitational lensing by host galaxy. We used photometric R band filter as expecting that redder part of optical spectrum should be more dominated due to high redshift z=1.4.
Instrument: Catalog: SIMBAD Bessell (B): +*.*, Bessell (V): +*.* Bessell (R): +16.4, Bessell (I): +*.* CCD: ATIK-383L+ FILTERS: R TELESCOPE: C11, 1623.0mm PRiSMv10, Astrometrica Site: ORIGIN: Cepheid Observatory, India, Vorion Scientific, India SITELAT: +24:55:00:00 SITELONG:+75:33:58:99 Observers: V.K.Agnihotri, B. Kumar, S. Mahawar, K.Vora Remark: Sky Clear. End
Cosmology with Time Delay Strong Lensing by Kenneth Wong