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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"

28046 results found.

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