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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"

18323 results found.

  1. GRB 990510: optical observations
  2. GRB 990506 R band observations
  3. GRB 990510: BATSE Observations
  4. GRB 990510 optical observations
  5. GRB 990506 Radio Observations
  6. GRB 990123, optical monitoring
  7. GRB 990506, optical observations
  8. GRB 990506, Optical Observations
  9. GRB 990506 optical observations
  10. GRB 990506, optical observations
  11. GRB 990506, optical observations from +1 to +3 hours
  12. GRB 990506, optical observations
  13. GRB990506 observation plan
  14. GRB 970228: Redshift and properties of the host galaxy
  15. GRB 990316 Optical Observations
  16. GRB990316, Optical observations
  17. GRB 990316 optical observations
  18. GRB990316: simultaneous optical observation
  19. GRB 990123, Field Photometry
  20. GRB 990217 Optical Observations
  21. BATSE Flight Anomaly
  22. GRB990123 observations
  23. GRB990123, Optical Observation
  24. GRB 990123: Discovery of the Probable Host Galaxy
  25. GRB 990123: Reduced HST Images
  26. GRB19990123 observations
  27. GRB 990123: BVRI standards in the field
  28. GRB981220, field photometry
  29. GRB990123, Optical observation
  30. GRB990123, Upcoming HST Service Observations
  31. GRB990123, 15-GHz limits
  32. GRB 990123: New Constraints on Possible Foreground Galaxies
  33. GRB990123 Optical Observations
  34. GRB990123, Probability of gravitational lensing
  35. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  36. GRB990123, Preliminary Lens Search Results
  37. GRB990123, Optical BVRI Observations
  38. GRB 990123: near-infrared observations.
  39. GRB990123, OSSE observations
  40. GRB990123: NIR Observation
  41. "GRB 990123: New BV Observations"
  42. GRB 990123: New Optical Observations, Decay Measure
  43. GRB 990123 Optical Follow-Up
  44. GRB 990123: Possible Gravitationally Lensed Burst?
  45. GRB990123, optical observation
  46. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  47. GRB 990123 r-band photometry
  48. GRB 990123 Optical Follow-up
  49. GRB990123, early optical counterpart detection
  50. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  51. Optical Observations of GRB 981220
  52. GRB 981226: radio variable
  53. GRB 981226 Optical Observations
  54. GRB981226 BeppoSAX follow up
  55. GRB 981226
  56. GRB 981226 optical observations
  57. GRB 981220:Optical Observations
  58. GRB981226, BeppoSAX Christmas GRB
  59. GRB 981226 optical observations
  60. GRB 981220, radio observations
  61. GRB 981220
  62. GRB 980326/Host Galaxy
  63. BeppoSAX NFI Observation of GRB980425
  64. GRB980329 R,I flux calibration and R,I,K upper limits
  65. GRB980425 Optical Follow-up
  66. GRB970508 optical observations
  67. GRB980519, Optical Observations
  68. GRB980703 optical photometry
  69. GRB980703 optical observations
  70. GRB980703 Transient Optical Follow-Up
  71. GRB980703: LOTIS observation at early times
  72. BeppoSAX NFI observations of GRB 980703
  73. GRB 980703: ASM Position & Intensity
  74. GRB980703 optical followup
  75. Radio observations of SGRs
  76. SGR1900+14 field optical observations
  77. GRB 980613: Optical transient and its host galaxy
  78. GRB 980613: Detection of the probable host galaxy
  79. GRB 980613 Optical Observations
  80. GRB 980613 optical observations
  81. Discovery of a new SGR source, SGR1627-41
  82. GRB980613 Optical Observations
  83. GRB980613 observations from Palomar
  84. GRB980613 BeppoSAX-NFI follow up
  85. GRB980613 Near Infra-Red Observations
  86. GRB971214 Secondary Standards
  87. GRB980519 Secondary Standards
  88. GRB 980519 Optical Observations
  89. GRB 980519
  90. GRB980519 optical observations
  91. GRB 980519 Optical Observations
  92. GRB970519, optical follow-up at Schmidt Calern
  93. GRB980519 Optical Observations
  94. GRB 980519 Optical Observations
  95. GRB980515, BeppoSAX IAUC to be submitted
  96. BSAX Observations of GRB980425 field
  97. SAX J0840.7+2248 Optical Observations
  98. GRB980425: optical obs.
  99. GRB980425: Radio Observations
  100. report on BSAX observations of GRB980425

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