Author: cepheids

Review By Jerry Hillburn

cepheids

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

(see https://posts.3cepheids.co.in/wp/photometry/apophis-photometric-curve/).

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/

Jerry Hilburn

Apophis Photometric Curve

cepheids1 Comment

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.

Apophis Photometric Curve

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

Review By Khushi Arora

cepheids

“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 science and 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.

Khushi Arora

Space Rock: Apophis

cepheids

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.

Apophis

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

https://www.youtube.com/watch?v=gjS0c1mHAuU

Optical part of gravitational lens system, QSO 0957+561

cepheids

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).

For more reading:

https://wwwmpa.mpa-garching.mpg.de/~komatsu/meetings/ds2013/schedule/suyu_desitterii.pdf

https://iopscience.iop.org/article/10.1086/320462/pdf

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

https://www.youtube.com/watch?v=YECujbmyTMo

R/I Photometry: S5 0716+714

cepheids

Image:
Object: S5 0716+714/8C 0716+714 — BL Lac
DATE-OBS: 2021-02-19T16:59:54.7152
EXPTIME: 3600.00 (seconds)
SUBFRMS: 60
OBJCTRA: 07 21 55.576
OBJCTDEC: +71 20 36.22
Instrument:
Catalog: SIMBAD
Bessell (B): +15.5, Bessell (V): +14.17
Bessell (R): +14.27, 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. The S5 0716+714 seems brighten about +1.0 mag at R band.
End

https://www.youtube.com/watch?v=5zwQmz9-1TU

Comet 409P/LONEOS-Hill

cepheids

Image:
Object: Comet 409P/LONEOS-Hill
DATE-OBS: 2021-02-17T22:11:27
EXPTIME: 3000.00 (seconds)
SUBFRMS: 25
OBJCTRA: 13 05 29.257
OBJCTDEC: +08 54 09.190
Instrument:
Catalog: UCAC4
Bessell (B): +*.*, Bessell (V): +*.*
Bessell (R): +15.7, 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

Photometry: HAT-P-30b

cepheids

Exo-Planet, Class confirmed:
HAT-P-30b
Imaged/Calibration/Image solve:
PRiSM v11
Photometry and Data Fitting:
HOPS 3.0/Platform: Python 3.7.6
Instrument:
CCD: ATIK-383L+ mono
FILTERS: R
TELESCOPE: C11, 1623.0mm
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

Comet C/2021 A1 (Leonard)

cepheids

Image:
Object: Comet C/2021 A1 (Leonard)
DATE-OBS: 2021-02-12T23:17:45
EXPTIME: 2250.00 (seconds)
SUBFRMS: 50
OBJCTRA: 14 01 27.281
OBJCTDEC: +49 38 36.060
Instrument:
Catalog: UCAC4
Bessell (B): +*.*, Bessell (V): +*.*
Bessell (R): +18.3, 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. As per, Prof. Seiichi Yoshida comet@aerith.net, it may attend mag around +4.0 and go visible to eyes in mid of Dec-2021
End

COMET C/2021 A4 (NEOWISE)

cepheids

Image:
Object: Comet C/2021 A4 (NEOWISE)
DATE-OBS: 2021-02-10T14:41:31
EXPTIME: 990.00 (seconds)
SUBFRMS: 22
OBJCTRA: 07 29 52.575
OBJCTDEC: +65 13 20.642
Instrument:
Catalog: UCAC4
Bessell (B): +*.*, Bessell (V): +*.*
Bessell (R): +14.9, 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