brajesh

Brajesh Kumar

 Professor
Udaipur Solar Observatory
Physical Research Laboratory
Dewali, Badi Road, Udaipur 313 004, Rajasthan, INDIA.

E-mail: [email protected]
Telephone: +91-294-2457214, Fax: +91-294-2457202

My research interests include:


The studies related to the seismic investigation of the Sun are carried out using the data obtained from GONG and the space missions SOHO and SDO. We are a part of the international network of six ground based telescopes known as GONG which is dedicated to the continuous observations of the Sun aimed for helioseismology. The data from these instruments are also used to study the impulsive velocity flows on the Sun's surface taking place during solar energetic events. These impulsive flows are correlated with the high energy emissions in the solar environment like H-alpha brightenings and X-ray emissions. The ground based daily H-alpha observations from USO and space based X-ray observations from RHESSI and GOES are used for analysing these solar transients.
Estimation of astronomical seeing is very important for ground based high resolution observations. A study has been carried out at the lake site of USO using burst of solar H-alpha images to estimate the diurnal and seasonal variations in seeing. The results from this study have helped in the design and development of a solar adaptive optics (SAO) system at USO. The SAO is now deployed on the Multi-Application Solar Telescope (MAST) of USO for high resolution observations of the Sun simultaneously at different heights. The MAST is now operational and giving very good quality high-resolution images of the Sun. The multi-height narrow-band filtergrams obtained from MAST will be useful for the study of propagation of waves in the active regions. The spectro-polarimetric observations from MAST will be used to study the velocity and magnetic transients appearing during the large flares and their influences in the solar atmosphere.


Selected Publications :
  1. On the signatures of flare-induced global waves in the Sun: GOLF and VIRGO observations
    Brajesh Kumar, Savita Mathur, Rafael A. Garcia, and Antonio Jimenez (2017). Monthly Notices of the Royal Astronomical Society, Vol. 471 , 4677.

  2. Analysis of sudden variations in photospheric magnetic fields during a large flare and their influences in the solar atmosphere
    Brajesh Kumar, A. Raja Bayanna, P. Venkatakrishnan, and Shibu K. Mathew (2016). Research in Astronomy and Astrophysics, Vol. 16 No. 8, 97.

  3. On the line profile changes observed during the X2.2 class flare in the active region NOAA 11158
    A. Raja Bayanna, Brajesh Kumar, P. Venkatakrishnan, Shibu K. Mathew, Ravindra, B., S. Mathur, and R. A. Garcia (2014). Research in Astronomy and Astrophysics, Vol. 14 No. 2, 207.

  4. A study of the relation between intensity oscillations and magnetic field parameters in a sunspot: Hinode observations
    A. Raja Bayanna, Shibu K. Mathew, Brajesh Kumar, Rohan E. Louis, and P. Venkatakrishnan (2014). Research in Astronomy and Astrophysics, Vol. 14 No. 11, 1458.

  5. On the flare-induced seismicity in the active region NOAA 10930 and related enhancement of global waves in the Sun
    Brajesh Kumar, P. Venkatakrishnan, S. Mathur, Sanjiv K. Tiwari, and R. A. Garcia (2011). The Astrophysical Journal, 711, 12.

  6. On the flare induced high-frequency global waves in the Sun
    Brajesh Kumar, S. Mathur, R. A. Garcia, and P. Venkatakrishnan (2010). The Astrophysical Journal Letters, 743, 29.

  7. Evidence of enhanced high-frequency velocity oscillations in the Sun observed during solar flare using disk-integrated Doppler signals
    Brajesh Kumar, P. Venkatakrishnan (2009). ASP Conf. Series, 416, 333.

  8. Co-spatial evolution of photospheric Doppler enhancements and H-alpha flare ribbons observed during the solar flare of 2003 October 28
    P. Venkatakrishnan, Brajesh Kumar, and Wahab Uddin (2008). MNRAS Letters, 387, 69.

  9. Development of a low-order Adaptive optics system at Udaipur Solar Observatory
    A. R. Bayanna, Brajesh Kumar,, R. E. Louis and S. K. Mathew (2008). J. Astrophys. Astron., 353, 29.

  10. Site characterization using solar H-alpha images
    Brajesh Kumar, P. Venkatakrishnan, A. Raja Bayanna and K. Venugopalan (2007). Solar Phys., 241, 427.

  11. An Image Stabilization System for solar observations
    R. Sridharan, A. Raja Bayanna, R. E. Louis, Brajesh Kumar, P. Venkatakrishnan, and S. K. Mathew (2007). Proc. SPIE, 6689, 66890Z.

  12. Analysis of enhanced velocity signals observed during solar flares
    Brajesh Kumar, and B. Ravindra     (2006). J. Astrophys. Astron., 27, 425.

  13. Preliminary results on the calibration and control of an adaptive optics system
    Brajesh Kumar, R. Sridharan, A. Raja Bayanna, and P. Venkatakrishnan (2005). Bull. Astron. Soc. India, 33, 413.

  14. The pattern of moving magnetic inhomogeneities in and around sunspots
    B. Ravindra, P. Venkatakrishnan, and Brajesh Kumar (2004). Solar Phys., 225, 47.

  15. On the rapid variations of solar magnetic fields
    P. Venkatakrishnan, Brajesh Kumar, and B. Ravindra (2003). Bull. Astron. Soc. India, 31, 299.

  16. Variation of acoustic power with magnetic field as seen in GONG+ data
    P. Venkatakrishnan,, Brajesh Kumar, and S. C. Tripathy (2002). Solar Phys., 211, 77.

  17. Search for spatial variability in the solar acoustic spectrum
    P. Venkatakrishnan,, Brajesh Kumar, and S. C. Tripathy (2001). Solar Phys., 202, 229.

  18. Analysis of hysteresis effect in p-mode frequencies and solar activity indices
    S. C. Tripathy,, Brajesh Kumar, K. Jain, and A. Bhatnagar (2001). Solar Phys., 200, 3.

  19. Empirical estimate of p-mode frequency shift for solar cycle 23
    K. Jain, S. C. Tripathy, A. Bhatnagar, and, Brajesh Kumar (2000). Solar Phys., 192, 487.

  20. p-modes in and away from a sunspot
    Brajesh Kumar,, R. Jain, S. C. Tripathy, H. O. Vats, and M. R. Deshpande (2000). Solar Phys., 191, 295.

  21. H-alpha intensity oscillations in solar flares
    R. Jain, S. C. Tripathy, L. Bharti, and, Brajesh Kumar (1999). ASP Conf. Series, 183, 256.