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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"

28038 results found.

  1. GRB990123, Optical observation
  2. GRB990123, 15-GHz limits
  3. GRB 990123: New Constraints on Possible Foreground Galaxies
  4. GRB990123 Optical Observations
  5. GRB990123, Probability of gravitational lensing
  6. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  7. GRB990123, Preliminary Lens Search Results
  8. On the Lensing Interpretation of GRB 990123
  9. Search for Potential Images of GRB 990123
  10. Search for Potential Images of GRB 990123
  11. GRB990123, Optical BVRI Observations
  12. GRB 990123: near-infrared observations.
  13. GRB990123, OSSE observations
  14. GRB990123: NIR Observation
  15. GRB990123, ASCA X-ray observation of afterglow
  16. "GRB 990123: New BV Observations"
  17. GRB 990123 Optical Follow-Up
  18. GRB 990123: BATSE Observations
  19. GRB990123 Optical Observations
  20. GRB 990123: New Optical Observations, Decay Measure
  21. GRB 990123 Optical Follow-Up
  22. GRB 990123: Possible Gravitationally Lensed Burst?
  23. GRB990123, optical observation
  24. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  25. GRB990123, Optical observation
  26. GRB 990123: Optical Decay Slope
  27. GRB 990123 r-band photometry
  28. GRB 990123 Optical Follow-up
  29. GRB990123, early optical counterpart detection
  30. GRB990123 Optical Observation
  31. Possible identification of SN1999E with GRB980910
  32. Optical Observations of GRB 981220
  33. GRB 981226: radio variable
  34. GRB981220
  35. GRB981220, Correction to GCN 179
  36. GRB 981220 Optical observations
  37. GRB 981226 Optical Observations
  38. GRB 981220 and GRB 981226, optical observations
  39. GRB981226 Optical Observations
  40. GRB981226 BeppoSAX follow up
  41. GRB 981226
  42. GRB 981226 optical observations
  43. GRB981220 B, R and I band observations
  44. Optical Observations of GRB981226
  45. GRB 981220:Optical Observations
  46. GRB 981226 optical observations
  47. GRB 981220
  48. GRB 981220, radio observations
  49. GRB981220 I-band Observations
  50. GRB 981220
  51. GRB 980326/Host Galaxy
  52. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  53. BeppoSAX NFI Observation of GRB980425
  54. GRB980329 R,I flux calibration and R,I,K upper limits
  55. GRB980425 Optical Follow-up
  56. GRB 980923 BATSE Observations
  57. SGR1900+14, BeppoSAX-GRBM observations
  58. GRB970508 optical observations
  59. GRB971214, association with a Galactic star?
  60. GRB980519, Optical Observations
  61. GRB980703 - BeppoSAX/GRBM detection
  62. GRB980703 optical photometry
  63. GRB 980703: BATSE Observations
  64. GRB980703 optical observations
  65. GRB980703: Radio transient
  66. GRB 980703: Spectrum of the proposed optical counterpart
  67. GRB980703 Transient Optical Follow-Up
  68. GRB980703: LOTIS observation at early times
  69. GRB980613 Optical Observations
  70. GRB980703 (I band observations)
  71. BeppoSAX NFI observations of GRB 980703
  72. GRB980519 observation report
  73. GRB980703 optical followup
  74. Radio observations of SGRs
  75. SGR1900+14 field optical observations
  76. GRB980613, optical observations
  77. GRB 980613: Optical transient and its host galaxy
  78. SGR1627-41, RXTE/ASM observations
  79. GRB 980613: Detection of the probable host galaxy
  80. Reduced error box of SGR 1627-41
  81. GRB 980613: BATSE Observations
  82. GRB 980613 Optical Observations
  83. GRB 980613 optical observations
  84. Discovery of a new SGR source, SGR1627-41
  85. GRB980613 Optical Observations
  86. GRB980613 observations from Palomar
  87. GRB 980613 optical/IR obs.
  88. GRB980613 Near Infra-Red Observations
  89. GRB971214 Secondary Standards
  90. GRB980519 Secondary Standards
  91. BATSE on-board GRB trigger change
  92. GRB 980519 Optical Observations
  93. GRB 980519
  94. GRB980519 optical observations
  95. GRB 980519 Optical Observations
  96. GRB980519 BATSE Observations
  97. GRB980519 Optical Observations
  98. GRB980519 Optical Observations
  99. GRB 980519 Optical Observations
  100. GRB980515, BeppoSAX IAUC to be submitted

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