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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"

28044 results found.

  1. GRB990123, Optical Observation
  2. GRB 990123: Discovery of the Probable Host Galaxy
  3. GRB 990123: Reduced HST Images
  4. GRB19990123 observations
  5. GRB 990123: BVRI standards in the field
  6. GRB981220, field photometry
  7. GRB990123, Optical observation
  8. GRB990123, 15-GHz limits
  9. GRB 990123: New Constraints on Possible Foreground Galaxies
  10. GRB990123 Optical Observations
  11. GRB990123, Probability of gravitational lensing
  12. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  13. GRB990123, Preliminary Lens Search Results
  14. On the Lensing Interpretation of GRB 990123
  15. Search for Potential Images of GRB 990123
  16. Search for Potential Images of GRB 990123
  17. GRB990123, Optical BVRI Observations
  18. GRB 990123: near-infrared observations.
  19. GRB990123, OSSE observations
  20. GRB990123: NIR Observation
  21. GRB990123, ASCA X-ray observation of afterglow
  22. "GRB 990123: New BV Observations"
  23. GRB 990123 Optical Follow-Up
  24. GRB 990123: BATSE Observations
  25. GRB990123 Optical Observations
  26. GRB 990123: New Optical Observations, Decay Measure
  27. GRB 990123 Optical Follow-Up
  28. GRB 990123: Possible Gravitationally Lensed Burst?
  29. GRB990123, optical observation
  30. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  31. GRB990123, Optical observation
  32. GRB 990123: Optical Decay Slope
  33. GRB 990123 r-band photometry
  34. GRB 990123 Optical Follow-up
  35. GRB990123, early optical counterpart detection
  36. GRB990123 Optical Observation
  37. Possible identification of SN1999E with GRB980910
  38. Optical Observations of GRB 981220
  39. GRB 981226: radio variable
  40. GRB981220
  41. GRB981220, Correction to GCN 179
  42. GRB 981220 Optical observations
  43. GRB 981226 Optical Observations
  44. GRB 981220 and GRB 981226, optical observations
  45. GRB981226 Optical Observations
  46. GRB981226 BeppoSAX follow up
  47. GRB 981226
  48. GRB 981226 optical observations
  49. GRB981220 B, R and I band observations
  50. Optical Observations of GRB981226
  51. GRB 981220:Optical Observations
  52. GRB 981226 optical observations
  53. GRB 981220
  54. GRB 981220, radio observations
  55. GRB981220 I-band Observations
  56. GRB 981220
  57. GRB 980326/Host Galaxy
  58. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  59. BeppoSAX NFI Observation of GRB980425
  60. GRB980329 R,I flux calibration and R,I,K upper limits
  61. GRB980425 Optical Follow-up
  62. GRB 980923 BATSE Observations
  63. SGR1900+14, BeppoSAX-GRBM observations
  64. GRB970508 optical observations
  65. GRB971214, association with a Galactic star?
  66. GRB980519, Optical Observations
  67. GRB980703 - BeppoSAX/GRBM detection
  68. GRB980703 optical photometry
  69. GRB 980703: BATSE Observations
  70. GRB980703 optical observations
  71. GRB980703: Radio transient
  72. GRB 980703: Spectrum of the proposed optical counterpart
  73. GRB980703 Transient Optical Follow-Up
  74. GRB980703: LOTIS observation at early times
  75. GRB980613 Optical Observations
  76. GRB980703 (I band observations)
  77. BeppoSAX NFI observations of GRB 980703
  78. GRB980519 observation report
  79. GRB980703 optical followup
  80. Radio observations of SGRs
  81. SGR1900+14 field optical observations
  82. GRB980613, optical observations
  83. GRB 980613: Optical transient and its host galaxy
  84. SGR1627-41, RXTE/ASM observations
  85. GRB 980613: Detection of the probable host galaxy
  86. Reduced error box of SGR 1627-41
  87. GRB 980613: BATSE Observations
  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. GRB 980613 optical/IR obs.
  94. GRB980613 Near Infra-Red Observations
  95. GRB971214 Secondary Standards
  96. GRB980519 Secondary Standards
  97. BATSE on-board GRB trigger change
  98. GRB 980519 Optical Observations
  99. GRB 980519
  100. GRB980519 optical observations

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Download all Circulars as a .tar.gz archive (updated once a day):
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