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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

31731 results found.

  1. GRB 990510: optical observations
  2. GRB990510, VI observations
  3. GRB 990506 R band observations
  4. GRB990510: X-ray afterglow
  5. VLT spectrum of GRB990510
  6. GRB 990510: Broad Band Break
  7. GRB 990510: BATSE Observations
  8. GRB990510: optical observation
  9. GRB 990510 Optical Observations
  10. GRB 990510, BVI photometry
  11. GRB 990510 optical observations
  12. GRB990510 optical observations
  13. GRB990510
  14. GRB 990510 optical observations
  15. GRB 990510 optical observations
  16. Galactic extinction towards GRB 990510
  17. IPN localization of GRB990510
  18. GRB 990506 Radio Observations
  19. GRB 990506: BATSE Observations
  20. GRB 990506, optical observations
  21. GRB 990506, Optical Observations
  22. GRB 990506 optical observations
  23. GRB 990506 optical observations
  24. GRB 990506, optical observations
  25. GRB990506 observation plan
  26. GRB 990506: Limits on the possible optical transient
  27. GRB 990506, armchair astronomy
  28. GRB 990506, optical observations from +1 to +3 hours
  29. GRB 990506, optical observations
  30. GRB990506 observation plan
  31. New IPN/RXTE error box for GRB990506
  32. IPN localization for GRB990506
  33. GRB 970228: Redshift and properties of the host galaxy
  34. GRB981220 VLBA observations
  35. GRB990321 REFINED IPN ANNULUS
  36. GRB990323 PRECISE IPN POSITION
  37. GRB 990316 Optical Observations
  38. GRB 990316, Radio observations
  39. GRB 990316, Optical observations
  40. GRB990316, Optical observations
  41. GRB 990316 optical observations
  42. GRB990316: simultaneous optical observation
  43. GRB990308 not a new SGR
  44. GRB 990308a and GRB 990308b
  45. GRB990308 (Trig. 7457), optical observations
  46. GRB981220, IPN localization
  47. GRB 981220, radio observations
  48. GRB 990123, Field Photometry
  49. GRB 990217, radio observations
  50. BATSE Resumes Normal Operations
  51. BATSE Flight Anomaly
  52. GRB990123: Caltech STIS Photometry and Images
  53. GRB990123 observations
  54. GRB990123, Optical Observation
  55. GRB 990123: Discovery of the Probable Host Galaxy
  56. GRB 990123: Reduced HST Images
  57. For Immediate Posting to GCN - HST Data GRB 990123 Available
  58. GRB19990123 observations
  59. GRB 990123: Updated Keck Spectroscopy Results
  60. GRB 990123 NOT Spectrum Update
  61. GRB990123, Optical observation
  62. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  63. GRB 990123: Publicly available reduced HST images
  64. GRB 990123: New Constraints on Possible Foreground Galaxies
  65. GRB990123 Optical Observations
  66. GRB990123, Probability of gravitational lensing
  67. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  68. GRB 990123: Continued Radio Observations
  69. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  70. On the Lensing Interpretation of GRB 990123
  71. Search for Potential Images of GRB 990123
  72. Search for Potential Images of GRB 990123
  73. GRB990123, Optical BVRI Observations
  74. GRB 990123: near-infrared observations.
  75. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  76. GRB990123: NIR Observation
  77. "GRB 990123: New BV Observations"
  78. GRB 990123 Optical Follow-Up
  79. GRB 990123; Addendum to GCN 223
  80. GRB 990123: BATSE Observations
  81. GRB 990123 Keck Spectrum update
  82. GRB990123 IPN annulus
  83. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  84. GRB990123 Optical Observations
  85. GRB 990123 Spectroscopic Redshifts
  86. GRB 990123: New Optical Observations, Decay Measure
  87. GRB 990123 Optical Follow-Up
  88. GRB 990123: Possible Gravitationally Lensed Burst?
  89. GRB990123, optical observation
  90. GRB 990123 optical observations
  91. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  92. GRB 990123 radio observations
  93. GRB 990123, new radio source
  94. GRB990123, Optical observation
  95. GRB 990123: Optical Decay Slope
  96. GRB 990123 r-band photometry
  97. GRB 990123 Optical Follow-up
  98. GRB990123, early optical counterpart detection
  99. GRB990123 Optical Observation
  100. GRB 990123: Bright New Source, Possible Optical Transient

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