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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"

28043 results found.

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

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