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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"

41612 results found.

  1. GRB990123 IPN annulus
  2. GRB990123 Optical Observations
  3. GRB 990123 Spectroscopic Redshifts
  4. GRB 990123: New Optical Observations, Decay Measure
  5. GRB 990123 Optical Follow-Up
  6. GRB 990123: Possible Gravitationally Lensed Burst?
  7. GRB990123, optical observation
  8. GRB 990123 optical observations
  9. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  10. GRB 990123 radio observations
  11. GRB 990123, new radio source
  12. GRB990123 optical observations
  13. GRB990123, Optical observation
  14. GRB 990123: Optical Decay Slope
  15. GRB 990123 r-band photometry
  16. GRB 990123 Optical Follow-up
  17. GRB990123 Optical Observation
  18. GRB990123, refined SAX-WFC position
  19. GRB 990123: Bright New Source, Possible Optical Transient
  20. GRB 990123, Radio observations
  21. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  22. SN 1999E & GRB 980919
  23. Possible identification of SN1999E with GRB980910
  24. Optical Observations of GRB 981220
  25. GRB 981226: radio variable
  26. GRB981220
  27. GRB981220, Correction to GCN 179
  28. GRB981220, Optical Observations
  29. GRB 981220 Optical observations
  30. GRB 981226 Optical Observations
  31. GRB 980613: Spectroscopy of the host galaxy
  32. GRB981226, sub-millimeter observations
  33. GRB981220, sub-millimeter observations
  34. GRB 981220 and GRB 981226, optical observations
  35. GRB981226 Optical Observations
  36. GRB981226 BeppoSAX follow up
  37. GRB 981226 radio observations
  38. GRB 981226
  39. GRB 981226 optical observations
  40. radio observations of GRB 981226
  41. GRB981220 B, R and I band observations
  42. GRB981226, BeppoSAX-NFI follow-up
  43. Optical Observations of GRB981226
  44. GRB 981220:Optical Observations
  45. GRB 981220 optical R and I observations
  46. GRB981226, BeppoSAX Christmas GRB
  47. GRB 981226 - Infrared Observations
  48. GRB 981226 optical observations
  49. GRB 981220
  50. GRB 981220, radio observations
  51. GRB981226 Optical Observation
  52. GRB 981220, radio observations
  53. GRB 981220: BeppoSAX/GRBM results
  54. GRB981220 I-band Observations
  55. GRB981220 Optical Observations
  56. GRB 981220
  57. GRB 981220 Optical Observations
  58. GRB 981220, optical observations
  59. GRB 980326/Host Galaxy
  60. GRB981220 IPN error box
  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. GRB980425: X-ray revised positions
  66. GRB 980923 BATSE Observations
  67. SGR1900+14, BeppoSAX-GRBM observations
  68. GRB980703 Very Long Baseline Interferometry
  69. GRB970508 optical observations
  70. GRB971214, association with a Galactic star?
  71. Optical Observations of the Host Galaxy of GRB 980519
  72. GRB980519, Optical Observations
  73. GRB980703, Host galaxy multicolor photometry
  74. GRB 980703 (NFI observations)
  75. GRB980703 optical photometry
  76. GRB 980703: BATSE Observations
  77. GRB980703 optical observations
  78. GRB980703: Radio transient
  79. GRB980703 H-band Observations
  80. GRB 980703: Spectrum of the proposed optical counterpart
  81. RXTE Observation of GRB 980706
  82. GRB980703: Spectrum of the proposed optical counterpart
  83. GRB980703 Transient Optical Follow-Up
  84. GRB980703: LOTIS observation at early times
  85. GRB980613 Optical Observations
  86. GRB 980703
  87. GRB980703 (I band observations)
  88. GRB 980703 H-band Observations
  89. GRB980703 (optical R observations)
  90. GRB980703: radio source/optical transient
  91. BeppoSAX NFI observations of GRB 980703
  92. GRB 980703: ASM Position & Intensity
  93. GRB980703
  94. GRB980703 optical followup
  95. Radio observations of SGRs
  96. SGR1900+14 field optical observations
  97. GRB 980613 Near-IR observations
  98. GRB980613, optical observations
  99. GRB 980613: Optical transient and its host galaxy
  100. SGR1627-41, RXTE/ASM observations

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