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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"

25751 results found.

  1. GRB990308, Possible new SGR~0209+70
  2. GRB 990123, Field Photometry
  3. GRB 990217 Optical Observations
  4. BATSE Flight Anomaly
  5. GRB990217: BeppoSAX/GRBM data
  6. GRB990123 observations
  7. GRB990217 Optical observation
  8. GRB990123, Optical Observation
  9. GRB 990123: Discovery of the Probable Host Galaxy
  10. GRB 990123: Reduced HST Images
  11. GRB19990123 observations
  12. GRB 990123: BVRI standards in the field
  13. GRB981220, field photometry
  14. GRB990123, Optical observation
  15. GRB990123, 15-GHz limits
  16. GRB 990123: New Constraints on Possible Foreground Galaxies
  17. GRB990123 Optical Observations
  18. GRB990123, Probability of gravitational lensing
  19. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  20. GRB990123, Preliminary Lens Search Results
  21. On the Lensing Interpretation of GRB 990123
  22. Search for Potential Images of GRB 990123
  23. Search for Potential Images of GRB 990123
  24. GRB990123, Optical BVRI Observations
  25. GRB 990123: near-infrared observations.
  26. GRB990123, OSSE observations
  27. GRB990123: NIR Observation
  28. GRB990123, ASCA X-ray observation of afterglow
  29. "GRB 990123: New BV Observations"
  30. GRB 990123 Optical Follow-Up
  31. GRB 990123: BATSE Observations
  32. GRB990123 Optical Observations
  33. GRB 990123: New Optical Observations, Decay Measure
  34. GRB 990123 Optical Follow-Up
  35. GRB 990123: Possible Gravitationally Lensed Burst?
  36. GRB990123, optical observation
  37. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  38. GRB990123, Optical observation
  39. GRB 990123: Optical Decay Slope
  40. GRB 990123 r-band photometry
  41. GRB 990123 Optical Follow-up
  42. GRB990123, early optical counterpart detection
  43. GRB990123 Optical Observation
  44. Possible identification of SN1999E with GRB980910
  45. Optical Observations of GRB 981220
  46. GRB 981226: radio variable
  47. GRB981220
  48. GRB981220, Correction to GCN 179
  49. GRB 981220 Optical observations
  50. GRB 981226 Optical Observations
  51. GRB 981220 and GRB 981226, optical observations
  52. GRB981226 Optical Observations
  53. GRB981226 BeppoSAX follow up
  54. GRB 981226
  55. GRB 981226 optical observations
  56. GRB981220 B, R and I band observations
  57. Optical Observations of GRB981226
  58. GRB 981220:Optical Observations
  59. GRB 981226 optical observations
  60. GRB 981220
  61. GRB 981220, radio observations
  62. GRB981220 I-band Observations
  63. GRB 981220
  64. GRB 980326/Host Galaxy
  65. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  66. BeppoSAX NFI Observation of GRB980425
  67. GRB980329 R,I flux calibration and R,I,K upper limits
  68. GRB980425 Optical Follow-up
  69. GRB 980923 BATSE Observations
  70. SGR1900+14, BeppoSAX-GRBM observations
  71. GRB970508 optical observations
  72. GRB971214, association with a Galactic star?
  73. GRB980519, Optical Observations
  74. GRB980703 - BeppoSAX/GRBM detection
  75. GRB980703 optical photometry
  76. GRB 980703: BATSE Observations
  77. GRB980703 optical observations
  78. GRB980703: Radio transient
  79. GRB 980703: Spectrum of the proposed optical counterpart
  80. GRB980703 Transient Optical Follow-Up
  81. GRB980703: LOTIS observation at early times
  82. GRB980613 Optical Observations
  83. GRB980703 (I band observations)
  84. BeppoSAX NFI observations of GRB 980703
  85. GRB980519 observation report
  86. GRB980703 optical followup
  87. Radio observations of SGRs
  88. SGR1900+14 field optical observations
  89. GRB980613, optical observations
  90. GRB 980613: Optical transient and its host galaxy
  91. SGR1627-41, RXTE/ASM observations
  92. GRB 980613: Detection of the probable host galaxy
  93. Reduced error box of SGR 1627-41
  94. GRB 980613: BATSE Observations
  95. GRB 980613 Optical Observations
  96. GRB 980613 optical observations
  97. Discovery of a new SGR source, SGR1627-41
  98. GRB980613 Optical Observations
  99. GRB980613 observations from Palomar
  100. GRB 980613 optical/IR obs.

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