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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"

28045 results found.

  1. GRB990217 Optical observation
  2. GRB990123, Optical Observation
  3. GRB 990123: Discovery of the Probable Host Galaxy
  4. GRB 990123: Reduced HST Images
  5. GRB19990123 observations
  6. GRB 990123: BVRI standards in the field
  7. GRB981220, field photometry
  8. GRB990123, Optical observation
  9. GRB990123, 15-GHz limits
  10. GRB 990123: New Constraints on Possible Foreground Galaxies
  11. GRB990123 Optical Observations
  12. GRB990123, Probability of gravitational lensing
  13. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  14. GRB990123, Preliminary Lens Search Results
  15. On the Lensing Interpretation of GRB 990123
  16. Search for Potential Images of GRB 990123
  17. Search for Potential Images of GRB 990123
  18. GRB990123, Optical BVRI Observations
  19. GRB 990123: near-infrared observations.
  20. GRB990123, OSSE observations
  21. GRB990123: NIR Observation
  22. GRB990123, ASCA X-ray observation of afterglow
  23. "GRB 990123: New BV Observations"
  24. GRB 990123 Optical Follow-Up
  25. GRB 990123: BATSE Observations
  26. GRB990123 Optical Observations
  27. GRB 990123: New Optical Observations, Decay Measure
  28. GRB 990123 Optical Follow-Up
  29. GRB 990123: Possible Gravitationally Lensed Burst?
  30. GRB990123, optical observation
  31. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  32. GRB990123, Optical observation
  33. GRB 990123: Optical Decay Slope
  34. GRB 990123 r-band photometry
  35. GRB 990123 Optical Follow-up
  36. GRB990123, early optical counterpart detection
  37. GRB990123 Optical Observation
  38. Possible identification of SN1999E with GRB980910
  39. Optical Observations of GRB 981220
  40. GRB 981226: radio variable
  41. GRB981220
  42. GRB981220, Correction to GCN 179
  43. GRB 981220 Optical observations
  44. GRB 981226 Optical Observations
  45. GRB 981220 and GRB 981226, optical observations
  46. GRB981226 Optical Observations
  47. GRB981226 BeppoSAX follow up
  48. GRB 981226
  49. GRB 981226 optical observations
  50. GRB981220 B, R and I band observations
  51. Optical Observations of GRB981226
  52. GRB 981220:Optical Observations
  53. GRB 981226 optical observations
  54. GRB 981220
  55. GRB 981220, radio observations
  56. GRB981220 I-band Observations
  57. GRB 981220
  58. GRB 980326/Host Galaxy
  59. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  60. BeppoSAX NFI Observation of GRB980425
  61. GRB980329 R,I flux calibration and R,I,K upper limits
  62. GRB980425 Optical Follow-up
  63. GRB 980923 BATSE Observations
  64. SGR1900+14, BeppoSAX-GRBM observations
  65. GRB970508 optical observations
  66. GRB971214, association with a Galactic star?
  67. GRB980519, Optical Observations
  68. GRB980703 - BeppoSAX/GRBM detection
  69. GRB980703 optical photometry
  70. GRB 980703: BATSE Observations
  71. GRB980703 optical observations
  72. GRB980703: Radio transient
  73. GRB 980703: Spectrum of the proposed optical counterpart
  74. GRB980703 Transient Optical Follow-Up
  75. GRB980703: LOTIS observation at early times
  76. GRB980613 Optical Observations
  77. GRB980703 (I band observations)
  78. BeppoSAX NFI observations of GRB 980703
  79. GRB980519 observation report
  80. GRB980703 optical followup
  81. Radio observations of SGRs
  82. SGR1900+14 field optical observations
  83. GRB980613, optical observations
  84. GRB 980613: Optical transient and its host galaxy
  85. SGR1627-41, RXTE/ASM observations
  86. GRB 980613: Detection of the probable host galaxy
  87. Reduced error box of SGR 1627-41
  88. GRB 980613: BATSE Observations
  89. GRB 980613 Optical Observations
  90. GRB 980613 optical observations
  91. Discovery of a new SGR source, SGR1627-41
  92. GRB980613 Optical Observations
  93. GRB980613 observations from Palomar
  94. GRB 980613 optical/IR obs.
  95. GRB980613 Near Infra-Red Observations
  96. GRB971214 Secondary Standards
  97. GRB980519 Secondary Standards
  98. BATSE on-board GRB trigger change
  99. GRB 980519 Optical Observations
  100. GRB 980519

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