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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"

28039 results found.

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