Skip to main content
New! BOOM Notices and Schema v7.0.0. 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.

Advanced Search Examples (click to copy):

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

35441 results found.

  1. Short-Hard GRB 070209: PROMPT Observations
  2. GRB 070318: Gemini + Magellan spectra
  3. GRB 070318: absorption-line redshift
  4. GRB070318: Swift-XRT refined analysis
  5. GRB 070318: Swift/UVOT Continued Observations
  6. GRB 070318, Swift-BAT refined analysis
  7. IBAS Alert n. 4176: not a GRB
  8. GRB 070318: Swift detection of a burst with an optical afterglow
  9. GRB 070311: Late Central Engine Activity Optical Flare??
  10. GRB 070311: MDM Optical Monitoring
  11. VLA observation of GRB 070311
  12. GRB 070311: Tautenburg sees afterglow fading
  13. IBAS Alert n. 4169: not a GRB
  14. GRB 070311: Optical observation.
  15. GRB 070311: Optical Brightening
  16. GRB 070306: possible emission-line redshift
  17. GRB 070311: SARA upper limit
  18. GRB 070309: variability of the XRT afterglow candidate
  19. GRB 070311: MDM Optical Follow-up
  20. GRB 070311: RAPTOR Detection of Optical Emission
  21. GRB070311: FRAM early follow-up limit
  22. GRB 070311: P60 Observations
  23. GRB 070311: MDM Optical Detection
  24. GRB 070311: Swift/UVOT Upper Limits
  25. GRB 070311: MITSuME Okayama Optical Observation
  26. GRB 070311: Swift-XRT refined analysis
  27. GRB 070311: PAIRITEL confirmation of variability of REM candidate
  28. GRB 070311: REM candidate afterglow
  29. GRB 070311: a long GRB detected by INTEGRAL
  30. GRB060901: Candidate optical afterglow
  31. GRB070309: Swift/XRT possible afterglow detection
  32. GRB 070125: Chandra X-ray Confirmation of Jet Break
  33. GRB 070309: Swift/UVOT Upper Limits
  34. GRB 070306, optical observation
  35. Swift UVOT Finding Charts for GRB 070309
  36. GRB 070309: A long GRB detected by INTEGRAL
  37. GRB 070125: X-ray light curve analysis
  38. VLA observation of GRB 070306
  39. IBAS Alert 4162: Not a GRB
  40. GRB 070306: NOT observations
  41. GRB 070306 Swift/UVOT refined analysis
  42. GRB070306: confirmation of near infrared afterglow
  43. GRB 070306: ART-3 early optical and near infrared constraints
  44. GRB 070306: IR observations and candidate afterglow
  45. GRB 070306, Swift-BAT refined analysis
  46. GRB 070306: XRT Team Refined Analysis
  47. GRB 070306: Optical and IR observations with KANATA
  48. GRB070306 - SDSS Pre-burst Observations
  49. GRB 070306: Swift detection of a burst
  50. GRB 070223: NIR observations at WHT
  51. GRB070227: Swift-XRT refined analysis
  52. GRB 060605 new redshift
  53. GRB 070125, deep late-time optical observation
  54. VLA observation of GRB 070224
  55. GRB 070227: optical observations
  56. GRB 070223: Optical Observations
  57. GRB 070227: optical observations
  58. GRB 070227: Swift/UVOT Upper Limits
  59. GRB 070227: TAROT La Silla observatory optical observations
  60. GRB 070227, Swift-BAT refined analysis
  61. GRB070227: possible X-ray afterglow detection
  62. GRB 070227: Swift detection of a burst in ground analysis
  63. GRB 920925C: optical afterglow candidate
  64. GRB 070224: Optical afterglow confirmation
  65. IBAS Alert n. 4144: not a GRB
  66. GRB 070224: Swift/UVOT Upper Limits
  67. VLA observation of GRB 070223
  68. VLA observation of GRB 070220
  69. GRB070224: Magellan Imaging Observations
  70. GRB 070224: WHT K-band imaging
  71. GRB 070224: MDM Observations
  72. GRB 070224: SARA upper limit
  73. GRB070224: Swift-XRT Refined Analysis
  74. GRB 070224: optical afterglow candidate
  75. GRB 070224, Swift-BAT refined analysis
  76. GRB 070224: MASTER-Net refind analysis
  77. GRB 070224: MASTER-VWF-Kislovodsk observations
  78. GRB 070224: MASTER observations
  79. GRB 070224: Swift detection of a burst
  80. GRB 070223: Optical observations
  81. GRB070223: Swift/UVOT refined analysis
  82. GRB 070223: Optical-IR observation with KANATA
  83. GRB 070223, Swift-BAT refined analysis
  84. GRB 070223: Swift-XRT Refined Analysis
  85. GRB 070220: pseudo-z~2.15 from spectral parameters of the prompt
  86. GRB070223 - SDSS Pre-Burst Observations
  87. GRB 070223: Liverpool Telescope Possible Afterglow Candidate
  88. GRB 070223: MDM Observations
  89. GRB070223: Swift burst
  90. Konus-Wind and Konus-A observations of GRB 070220
  91. GRB 070220: MITSuME Okayama Optical Observation
  92. GRB 070220: ART-3 Optical and NIR limits
  93. GRB 070220 Swift-BAT Refined Analysis
  94. Swift/UVOT refined analysis of GRB070220
  95. GRB 070209: Swift XRT refined analysis
  96. GRB 070220: Swift-XRT Refined Analysis
  97. GRB 070220: Observation with the KANATA 1.5m telescope
  98. GRB 070219: Gemini Observations
  99. GRB 070220 : Faulkes Telescope North optical limit
  100. GRB 070220: Swift detection of a burst

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov