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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"

24610 results found.

  1. GRB990806 UBVRIJHK observations
  2. GRB 990712 Optical Observations
  3. GRB 990712
  4. Late-time HST/STIS Observations of GRB 990510
  5. BeppoSAX NFI Observation of GRB990705
  6. BeppoSAX NFI Observation of GRB990705
  7. GRB 990705, R-band observations
  8. Infrared and Optical Observations of GRB990705
  9. GRB990704: SAX-NFI results summary
  10. GRB990704 radio and optical observations
  11. GRB990704
  12. GRB990704, optical observations
  13. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  14. Optical Observations of GRB990627
  15. BeppoSAX: GRB990625
  16. Late-time HST/STIS Observation of GRB 990123
  17. Optical Observations of GRB 990506
  18. GRB990527 Optical Observations
  19. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  20. Late Afterglows of GRBs 990510, 990123
  21. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  22. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  23. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  24. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  25. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  26. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  27. radio observations of X-ray/GRB transient field
  28. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  29. Optical report on X-ray/GRB transient
  30. radio detection of X-ray/GRB transient
  31. BeppoSAX: A new fast X-ray transient
  32. GRB 990510: optical observations
  33. GRB 990510: optical linear polarization
  34. GRB 990510: optical observations
  35. GRB990510: X-ray afterglow
  36. GRB 990510: Broad Band Break
  37. GRB 990510: BATSE Observations
  38. GRB 990510: BeppoSAX/GRBM observations
  39. GRB990510 optical observations
  40. GRB 990510 optical observations
  41. GRB 990506 Radio Observations
  42. GRB 990123, optical monitoring
  43. GRB 990506: BATSE Observations
  44. GRB 990506, optical observations
  45. GRB 990506, Optical Observations
  46. GRB 990506 optical observations
  47. GRB 990506, optical observations
  48. GRB 990506, armchair astronomy
  49. GRB 990506, optical observations from +1 to +3 hours
  50. GRB 990506, optical observations
  51. GRB990506 observation plan
  52. IPN localization for GRB990506
  53. GRB990323 PRECISE IPN POSITION
  54. GRB 990316 Optical Observations
  55. GRB 990316 optical observations
  56. GRB990316: simultaneous optical observation
  57. GRB990316 - Optical null results
  58. GRB990308 not a new SGR
  59. GRB 990308a and GRB 990308b
  60. GRB990308, Possible new SGR~0209+70
  61. GRB 990123, Field Photometry
  62. GRB 990217 Optical Observations
  63. BATSE Flight Anomaly
  64. GRB990217: BeppoSAX/GRBM data
  65. GRB990123 observations
  66. GRB990217 Optical observation
  67. GRB990123, Optical Observation
  68. GRB 990123: Discovery of the Probable Host Galaxy
  69. GRB 990123: Reduced HST Images
  70. GRB19990123 observations
  71. GRB 990123: BVRI standards in the field
  72. GRB981220, field photometry
  73. GRB990123, Optical observation
  74. GRB990123, 15-GHz limits
  75. GRB 990123: New Constraints on Possible Foreground Galaxies
  76. GRB990123 Optical Observations
  77. GRB990123, Probability of gravitational lensing
  78. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  79. GRB990123, Preliminary Lens Search Results
  80. On the Lensing Interpretation of GRB 990123
  81. Search for Potential Images of GRB 990123
  82. Search for Potential Images of GRB 990123
  83. GRB990123, Optical BVRI Observations
  84. GRB 990123: near-infrared observations.
  85. GRB990123, OSSE observations
  86. GRB990123: NIR Observation
  87. GRB990123, ASCA X-ray observation of afterglow
  88. "GRB 990123: New BV Observations"
  89. GRB 990123 Optical Follow-Up
  90. GRB 990123: BATSE Observations
  91. GRB990123 Optical Observations
  92. GRB 990123: New Optical Observations, Decay Measure
  93. GRB 990123 Optical Follow-Up
  94. GRB 990123: Possible Gravitationally Lensed Burst?
  95. GRB990123, optical observation
  96. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  97. GRB990123, Optical observation
  98. GRB 990123: Optical Decay Slope
  99. GRB 990123 r-band photometry
  100. GRB 990123 Optical Follow-up

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