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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"

24849 results found.

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

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