Skip to main content
Circulars over Kafka event name backfill. See news and announcements

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.

Lucene Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

3036 results found.

  1. GRB 051022 Chandra Observations scheduled
  2. GRB 051022: SOAR JKs Observations
  3. GRB 051022, J & K-band observation
  4. GRB 051021: P200 Ks Observations
  5. GRB051021: Swift XRT analysis
  6. GRB 051016b: Gemini Near IR Observations
  7. GRB051008: Swift XRT refined analysis
  8. GRB 051001: AAT infra-red observations
  9. GRB 051001: ROTSE-III Optical Limits
  10. GRB050925: Swift/XRT limits
  11. GRB/SGR 050925: IR Observations
  12. GRB050922B: refined XRT analysis
  13. GRB050820B: analysis of the XMM-Newton observation
  14. Swift-BAT trigger 155764 is not a GRB
  15. GRB050916 : Swift-XRT refined analysis
  16. GRB050911: Upper limit on X-ray afterglow
  17. Swift-BAT trigger 155072 ground analysis
  18. GRB 050906: Swift XRT upper limit
  19. GRB 050904: early Swift XRT analysis results
  20. GRB 050827: Swift XRT preliminary analysis results
  21. GRB 050827: P200 NIR Observations
  22. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  23. GRB 050730: XRT refined analysis
  24. GRB 050724: Chandra Observations of the X-ray Afterglow
  25. GRB050713: analysis of the XMM-Newton observation
  26. GRB 050714a: Refined XRT analysis and afterglow confirmation
  27. GRB 050713: ARC NIR Detections and Identification of Fading
  28. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  29. GRB 050626: Swift XRT observations
  30. GRB 050408: ARC 3.5-meter NIR Observations
  31. GRB 050603 - XRT data analysis of the first day
  32. GRB 050525a, infrared observations
  33. GRB 050509b: refined XRT/Chandra afterglow position analysis
  34. XRF050522: NIR observations of XRT candidate
  35. XRF 050522: Continued NIR P200 Monitoring
  36. XRF050522: Near-infrared Observations
  37. XRF050509C: Chandra Afterglow Detection
  38. XRF 050509c: Swift XRT Upper Limit
  39. GRB 050520: P200 Observations
  40. GRB 050504: Swift XRT afterglow candidate has faded
  41. Refined Chandra analysis of GRB 050509b
  42. Chandra observation of GRB 050509b
  43. GRB 050502a: Swift XRT Upper Limit
  44. GRB (?) 050504: IR Observations, Intriguing Source
  45. GRB 050502: Confirmed variability of the afterglow candidate +
  46. GRB 050421: Further Analysis of IR imaging
  47. GRB 050421: IR Observations
  48. GRB050326: analysis of the XMM-Newton observation
  49. GRB050416B: IR observations
  50. GRB050416: P200 NIR Observations
  51. GRB 050408: Swift XRT measurement of possible jet break
  52. GRB 050408: Swift XRT analysis
  53. GRB050408: REM NIR and Optical observation
  54. GRB 050326 XMM-Newton observation
  55. GRB050223: analysis of the XMM-Newton observation
  56. Swift-BAT trigger 107873: No Swift XRT counterpart
  57. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  58. GRB 050306: REM optical-infrared observations
  59. GRB 050126: Confirmation of the NIR afterglow candidate
  60. GRB 050219b: candidate NIR afterglow
  61. GRB 050219b: Optical and near-IR observations from LCO
  62. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  63. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  64. GRB 050124: NIR Candidates from Keck/NIRC
  65. GRB050117: Palomar WIRC Ks-band observations
  66. NIR Observations of GRB 041219
  67. GRB 041211: Infrared Observations
  68. GRB041015: Near-Infrared observations
  69. GRB041006: Near Infrared observations
  70. GRB040827: analysis of the XMM-Newton observation
  71. GRB 040827: 2nd epoch of Magellan K-band imaging
  72. GRB 040827: Detection of NIR afterglow
  73. GRB 040812: Second epoch CXO Observations
  74. CXO observation of GRB 040812
  75. GRB 040730, infrared observations
  76. SGR 1806-20: no IR variability of the proposed counterparts
  77. SGR 1806-20, potential NIR counterpart
  78. GRB 040511: NIR observations with REM
  79. IBAS GRB alerts 1739, 1740, 1741
  80. GRB040223: Deep NIR NTT data re-analysis
  81. GRB 040223: Deep NIR NTT observations
  82. GRB 040223: REM IJK Observations
  83. GRB 040223 XMM-Newton observation ...
  84. GRB 031203 XMM-Newton observation
  85. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  86. XMM-Newton Observation of GRB031203
  87. GRB 031203: Deep NIR NTT & VLT observations
  88. XMM-Newton Observation of GRB031203
  89. GRB 031203: IR NTTobservations do not confirm REM detection
  90. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  91. GRB 031203: IR REM Observations
  92. GRB 031203 XMM-Newton observation
  93. XRF030723: Palomar observations and proposed counterpart
  94. GRB030329: second XMM-Newton observation
  95. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  96. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  97. GRB 030528: tentative NIR counterpart
  98. GRB 030329: Optical limit (contemporaneous photography)
  99. GRB 030429: IR photometry with IRSF/SIRIUS
  100. GRB030501: TAROT candidate afterglow present in archival images

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov