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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"

28047 results found.

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

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