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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"

18332 results found.

  1. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  2. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  3. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  4. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  5. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  6. radio observations of X-ray/GRB transient field
  7. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  8. Optical report on X-ray/GRB transient
  9. GRB 990510: optical linear polarization
  10. GRB 990510: optical observations
  11. GRB 990506 R band observations
  12. GRB 990510: BATSE Observations
  13. GRB 990510 optical observations
  14. GRB 990506 Radio Observations
  15. GRB 990123, optical monitoring
  16. GRB 990506, optical observations
  17. GRB 990506, Optical Observations
  18. GRB 990506 optical observations
  19. GRB 990506, optical observations
  20. GRB 990506, optical observations from +1 to +3 hours
  21. GRB 990506, optical observations
  22. GRB990506 observation plan
  23. GRB 970228: Redshift and properties of the host galaxy
  24. GRB 990316 Optical Observations
  25. GRB990316, Optical observations
  26. GRB 990316 optical observations
  27. GRB990316: simultaneous optical observation
  28. GRB 990123, Field Photometry
  29. GRB 990217 Optical Observations
  30. BATSE Flight Anomaly
  31. GRB990123 observations
  32. GRB990123, Optical Observation
  33. GRB 990123: Discovery of the Probable Host Galaxy
  34. GRB 990123: Reduced HST Images
  35. GRB19990123 observations
  36. GRB 990123: BVRI standards in the field
  37. GRB981220, field photometry
  38. GRB990123, Optical observation
  39. GRB990123, Upcoming HST Service Observations
  40. GRB990123, 15-GHz limits
  41. GRB 990123: New Constraints on Possible Foreground Galaxies
  42. GRB990123 Optical Observations
  43. GRB990123, Probability of gravitational lensing
  44. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  45. GRB990123, Preliminary Lens Search Results
  46. GRB990123, Optical BVRI Observations
  47. GRB 990123: near-infrared observations.
  48. GRB990123, OSSE observations
  49. GRB990123: NIR Observation
  50. "GRB 990123: New BV Observations"
  51. GRB 990123: New Optical Observations, Decay Measure
  52. GRB 990123 Optical Follow-Up
  53. GRB 990123: Possible Gravitationally Lensed Burst?
  54. GRB990123, optical observation
  55. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  56. GRB 990123 r-band photometry
  57. GRB 990123 Optical Follow-up
  58. GRB990123, early optical counterpart detection
  59. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  60. Optical Observations of GRB 981220
  61. GRB 981226: radio variable
  62. GRB 981226 Optical Observations
  63. GRB981226 BeppoSAX follow up
  64. GRB 981226
  65. GRB 981226 optical observations
  66. GRB 981220:Optical Observations
  67. GRB981226, BeppoSAX Christmas GRB
  68. GRB 981226 optical observations
  69. GRB 981220, radio observations
  70. GRB 981220
  71. GRB 980326/Host Galaxy
  72. BeppoSAX NFI Observation of GRB980425
  73. GRB980329 R,I flux calibration and R,I,K upper limits
  74. GRB980425 Optical Follow-up
  75. GRB970508 optical observations
  76. GRB980519, Optical Observations
  77. GRB980703 optical photometry
  78. GRB980703 optical observations
  79. GRB980703 Transient Optical Follow-Up
  80. GRB980703: LOTIS observation at early times
  81. BeppoSAX NFI observations of GRB 980703
  82. GRB 980703: ASM Position & Intensity
  83. GRB980703 optical followup
  84. Radio observations of SGRs
  85. SGR1900+14 field optical observations
  86. GRB 980613: Optical transient and its host galaxy
  87. GRB 980613: Detection of the probable host galaxy
  88. GRB 980613 Optical Observations
  89. GRB 980613 optical observations
  90. Discovery of a new SGR source, SGR1627-41
  91. GRB980613 Optical Observations
  92. GRB980613 observations from Palomar
  93. GRB980613 BeppoSAX-NFI follow up
  94. GRB980613 Near Infra-Red Observations
  95. GRB971214 Secondary Standards
  96. GRB980519 Secondary Standards
  97. GRB 980519 Optical Observations
  98. GRB 980519
  99. GRB980519 optical observations
  100. GRB 980519 Optical Observations

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