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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"

28052 results found.

  1. GRB 990308a and GRB 990308b
  2. GRB990308, Possible new SGR~0209+70
  3. GRB 990123, Field Photometry
  4. GRB 990217 Optical Observations
  5. BATSE Flight Anomaly
  6. GRB990217: BeppoSAX/GRBM data
  7. GRB990123 observations
  8. GRB990217 Optical observation
  9. GRB990123, Optical Observation
  10. GRB 990123: Discovery of the Probable Host Galaxy
  11. GRB 990123: Reduced HST Images
  12. GRB19990123 observations
  13. GRB 990123: BVRI standards in the field
  14. GRB981220, field photometry
  15. GRB990123, Optical observation
  16. GRB990123, 15-GHz limits
  17. GRB 990123: New Constraints on Possible Foreground Galaxies
  18. GRB990123 Optical Observations
  19. GRB990123, Probability of gravitational lensing
  20. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  21. GRB990123, Preliminary Lens Search Results
  22. On the Lensing Interpretation of GRB 990123
  23. Search for Potential Images of GRB 990123
  24. Search for Potential Images of GRB 990123
  25. GRB990123, Optical BVRI Observations
  26. GRB 990123: near-infrared observations.
  27. GRB990123, OSSE observations
  28. GRB990123: NIR Observation
  29. GRB990123, ASCA X-ray observation of afterglow
  30. "GRB 990123: New BV Observations"
  31. GRB 990123 Optical Follow-Up
  32. GRB 990123: BATSE Observations
  33. GRB990123 Optical Observations
  34. GRB 990123: New Optical Observations, Decay Measure
  35. GRB 990123 Optical Follow-Up
  36. GRB 990123: Possible Gravitationally Lensed Burst?
  37. GRB990123, optical observation
  38. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  39. GRB990123, Optical observation
  40. GRB 990123: Optical Decay Slope
  41. GRB 990123 r-band photometry
  42. GRB 990123 Optical Follow-up
  43. GRB990123, early optical counterpart detection
  44. GRB990123 Optical Observation
  45. Possible identification of SN1999E with GRB980910
  46. Optical Observations of GRB 981220
  47. GRB 981226: radio variable
  48. GRB981220
  49. GRB981220, Correction to GCN 179
  50. GRB 981220 Optical observations
  51. GRB 981226 Optical Observations
  52. GRB 981220 and GRB 981226, optical observations
  53. GRB981226 Optical Observations
  54. GRB981226 BeppoSAX follow up
  55. GRB 981226
  56. GRB 981226 optical observations
  57. GRB981220 B, R and I band observations
  58. Optical Observations of GRB981226
  59. GRB 981220:Optical Observations
  60. GRB 981226 optical observations
  61. GRB 981220
  62. GRB 981220, radio observations
  63. GRB981220 I-band Observations
  64. GRB 981220
  65. GRB 980326/Host Galaxy
  66. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  67. BeppoSAX NFI Observation of GRB980425
  68. GRB980329 R,I flux calibration and R,I,K upper limits
  69. GRB980425 Optical Follow-up
  70. GRB 980923 BATSE Observations
  71. SGR1900+14, BeppoSAX-GRBM observations
  72. GRB970508 optical observations
  73. GRB971214, association with a Galactic star?
  74. GRB980519, Optical Observations
  75. GRB980703 - BeppoSAX/GRBM detection
  76. GRB980703 optical photometry
  77. GRB 980703: BATSE Observations
  78. GRB980703 optical observations
  79. GRB980703: Radio transient
  80. GRB 980703: Spectrum of the proposed optical counterpart
  81. GRB980703 Transient Optical Follow-Up
  82. GRB980703: LOTIS observation at early times
  83. GRB980613 Optical Observations
  84. GRB980703 (I band observations)
  85. BeppoSAX NFI observations of GRB 980703
  86. GRB980519 observation report
  87. GRB980703 optical followup
  88. Radio observations of SGRs
  89. SGR1900+14 field optical observations
  90. GRB980613, optical observations
  91. GRB 980613: Optical transient and its host galaxy
  92. SGR1627-41, RXTE/ASM observations
  93. GRB 980613: Detection of the probable host galaxy
  94. Reduced error box of SGR 1627-41
  95. GRB 980613: BATSE Observations
  96. GRB 980613 Optical Observations
  97. GRB 980613 optical observations
  98. Discovery of a new SGR source, SGR1627-41
  99. GRB980613 Optical Observations
  100. GRB980613 observations from Palomar

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