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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"

26364 results found.

  1. GRB 990506, optical observations
  2. GRB 990506, armchair astronomy
  3. GRB 990506, optical observations from +1 to +3 hours
  4. GRB 990506, optical observations
  5. GRB990506 observation plan
  6. IPN localization for GRB990506
  7. GRB990323 PRECISE IPN POSITION
  8. GRB 990316 Optical Observations
  9. GRB 990316 optical observations
  10. GRB990316: simultaneous optical observation
  11. GRB990316 - Optical null results
  12. GRB990308 not a new SGR
  13. GRB 990308a and GRB 990308b
  14. GRB990308, Possible new SGR~0209+70
  15. GRB 990123, Field Photometry
  16. GRB 990217 Optical Observations
  17. BATSE Flight Anomaly
  18. GRB990217: BeppoSAX/GRBM data
  19. GRB990123 observations
  20. GRB990217 Optical observation
  21. GRB990123, Optical Observation
  22. GRB 990123: Discovery of the Probable Host Galaxy
  23. GRB 990123: Reduced HST Images
  24. GRB19990123 observations
  25. GRB 990123: BVRI standards in the field
  26. GRB981220, field photometry
  27. GRB990123, Optical observation
  28. GRB990123, 15-GHz limits
  29. GRB 990123: New Constraints on Possible Foreground Galaxies
  30. GRB990123 Optical Observations
  31. GRB990123, Probability of gravitational lensing
  32. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  33. GRB990123, Preliminary Lens Search Results
  34. On the Lensing Interpretation of GRB 990123
  35. Search for Potential Images of GRB 990123
  36. Search for Potential Images of GRB 990123
  37. GRB990123, Optical BVRI Observations
  38. GRB 990123: near-infrared observations.
  39. GRB990123, OSSE observations
  40. GRB990123: NIR Observation
  41. GRB990123, ASCA X-ray observation of afterglow
  42. "GRB 990123: New BV Observations"
  43. GRB 990123 Optical Follow-Up
  44. GRB 990123: BATSE Observations
  45. GRB990123 Optical Observations
  46. GRB 990123: New Optical Observations, Decay Measure
  47. GRB 990123 Optical Follow-Up
  48. GRB 990123: Possible Gravitationally Lensed Burst?
  49. GRB990123, optical observation
  50. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  51. GRB990123, Optical observation
  52. GRB 990123: Optical Decay Slope
  53. GRB 990123 r-band photometry
  54. GRB 990123 Optical Follow-up
  55. GRB990123, early optical counterpart detection
  56. GRB990123 Optical Observation
  57. Possible identification of SN1999E with GRB980910
  58. Optical Observations of GRB 981220
  59. GRB 981226: radio variable
  60. GRB981220
  61. GRB981220, Correction to GCN 179
  62. GRB 981220 Optical observations
  63. GRB 981226 Optical Observations
  64. GRB 981220 and GRB 981226, optical observations
  65. GRB981226 Optical Observations
  66. GRB981226 BeppoSAX follow up
  67. GRB 981226
  68. GRB 981226 optical observations
  69. GRB981220 B, R and I band observations
  70. Optical Observations of GRB981226
  71. GRB 981220:Optical Observations
  72. GRB 981226 optical observations
  73. GRB 981220
  74. GRB 981220, radio observations
  75. GRB981220 I-band Observations
  76. GRB 981220
  77. GRB 980326/Host Galaxy
  78. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  79. BeppoSAX NFI Observation of GRB980425
  80. GRB980329 R,I flux calibration and R,I,K upper limits
  81. GRB980425 Optical Follow-up
  82. GRB 980923 BATSE Observations
  83. SGR1900+14, BeppoSAX-GRBM observations
  84. GRB970508 optical observations
  85. GRB971214, association with a Galactic star?
  86. GRB980519, Optical Observations
  87. GRB980703 - BeppoSAX/GRBM detection
  88. GRB980703 optical photometry
  89. GRB 980703: BATSE Observations
  90. GRB980703 optical observations
  91. GRB980703: Radio transient
  92. GRB 980703: Spectrum of the proposed optical counterpart
  93. GRB980703 Transient Optical Follow-Up
  94. GRB980703: LOTIS observation at early times
  95. GRB980613 Optical Observations
  96. GRB980703 (I band observations)
  97. BeppoSAX NFI observations of GRB 980703
  98. GRB980519 observation report
  99. GRB980703 optical followup
  100. Radio observations of SGRs

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