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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"

17651 results found.

  1. GRB990704, optical observations
  2. GRB990704: possible X-ray afterglow
  3. GRB990704
  4. GRB990704: BeppoSAX detection
  5. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  6. GRB 990627, radio observations
  7. Late-time HST/STIS Observation of GRB 990123
  8. Optical Observations of GRB 990506
  9. GRB 990506 Radio Transient
  10. GRB990527 Optical Observations
  11. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  12. IPN error box for GRB990527
  13. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  14. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  15. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  16. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  17. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  18. radio observations of X-ray/GRB transient field
  19. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  20. Optical report on X-ray/GRB transient
  21. radio detection of X-ray/GRB transient
  22. GRB 990510: optical linear polarization
  23. GRB 990510: optical observations
  24. GRB990510: X-ray afterglow
  25. GRB 990510 optical observations
  26. GRB990510: NFI X-ray source
  27. GRB 990506 Radio Observations
  28. GRB 990123, optical monitoring
  29. GRB 990506, optical observations
  30. GRB 990510: Final BeppoSAX-WFC Coordinates
  31. GRB 990506, Optical Observations
  32. GRB 990506 optical observations
  33. GRB 990506 optical observations
  34. GRB 990506, optical observations
  35. GRB990506 observation plan
  36. GRB 990506, optical observations from +1 to +3 hours
  37. GRB 990506, optical observations
  38. GRB990506 observation plan
  39. GRB 990316 Optical Observations
  40. GRB 990316 optical observations
  41. GRB990316: simultaneous optical observation
  42. GRB990308, Possible new SGR~0209+70
  43. GRB 990123, Field Photometry
  44. GRB 990217 Optical Observations
  45. BATSE Flight Anomaly
  46. GRB990217: BeppoSAX/GRBM data
  47. GRB990123 observations
  48. GRB990123, Optical Observation
  49. GRB 990123: Discovery of the Probable Host Galaxy
  50. GRB19990123 observations
  51. GRB 990123: BVRI standards in the field
  52. GRB981220, field photometry
  53. GRB990123, Optical observation
  54. GRB 990123: Publicly available reduced HST images
  55. GRB990123, Upcoming HST Service Observations
  56. GRB990123, 15-GHz limits
  57. GRB 990123: New Constraints on Possible Foreground Galaxies
  58. GRB990123 Optical Observations
  59. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  60. GRB 990123: Continued Radio Observations
  61. GRB990123, Preliminary Lens Search Results
  62. Search for Potential Images of GRB 990123
  63. GRB990123, Optical BVRI Observations
  64. GRB 990123: near-infrared observations.
  65. GRB990123, OSSE observations
  66. GRB990123: NIR Observation
  67. "GRB 990123: New BV Observations"
  68. GRB 990123: New Optical Observations, Decay Measure
  69. GRB 990123 Optical Follow-Up
  70. GRB 990123: Possible Gravitationally Lensed Burst?
  71. GRB990123, optical observation
  72. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  73. GRB 990123 r-band photometry
  74. GRB 990123 Optical Follow-up
  75. Optical Observations of GRB 981220
  76. GRB 981226: radio variable
  77. GRB 981226 Optical Observations
  78. GRB981226 BeppoSAX follow up
  79. GRB 981226
  80. GRB 981226 optical observations
  81. GRB 981220:Optical Observations
  82. GRB981226, BeppoSAX Christmas GRB
  83. GRB 981226 optical observations
  84. GRB 981220, radio observations
  85. GRB 981220
  86. GRB 980326/Host Galaxy
  87. BeppoSAX NFI Observation of GRB980425
  88. GRB980329 R,I flux calibration and R,I,K upper limits
  89. GRB980425 Optical Follow-up
  90. GRB970508 optical observations
  91. GRB980519, Optical Observations
  92. GRB 980703 (NFI observations)
  93. GRB980703 optical photometry
  94. GRB980703 optical observations
  95. GRB980703: Radio transient
  96. GRB980703 Transient Optical Follow-Up
  97. GRB980703: LOTIS observation at early times
  98. BeppoSAX NFI observations of GRB 980703
  99. GRB980703 optical followup
  100. SGR1627-41

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