Skip to main content
Passing of Scott Barthelmy, GCN Founder 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"
  1. GRB 070508: Multicolor optical observations and possible redshift limit
  2. GRB 070508: Swift-XRT refined analysis
  3. GRB 070508: Optical observation limiting magnitude
  4. GRB 070508: Optical afterglow detection
  5. GRB 070508: REM observations
  6. GRB 070508: TAROT La Silla observatory optical observations
  7. GRB 070508: Swift detection of an intense burst with an optical counterpart
  8. GRB070412: MAGIC telescope GeV observation
  9. Swift-BAT trigger 278809 is not a GRB
  10. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  11. GRB 070506: VLT redshift
  12. GRB070506: Swift/UVOT Observations
  13. GRB070506: Swift XRT refined analysis
  14. GRB 070506, Swift-BAT Refined Analysis
  15. GRB 070506: Swift detection of a burst with optical afterglow
  16. GRB 070412, deep LBT imaging
  17. GRB 070429A: Swift XRT further analysis
  18. GRB070429B: VLT observations
  19. GRB 070429A: optical observations
  20. GRB070429B: position correction
  21. GRB 070309: Swift-XRT afterglow confirmation
  22. GRB070429B: possible host galaxy detection
  23. VLA observation of GRB 070429B
  24. Swift/UVOT observations of GRB070429B
  25. GRB 070429B, Swift-BAT refined analysis
  26. Swift/UVOT observations of GRB070429A
  27. GRB 070429A: Swift XRT refined analysis
  28. GRB 070429A, Swift-BAT refined analysis
  29. GRB 070429A: optical and NIR observations
  30. GRB 070429B: Swift XRT refined analysis
  31. GRB 070429B: ROTSE-III Optical Limits
  32. GRB 070429B: Swift detection of a short burst
  33. GRB 070429: What's the temperature?
  34. GRB 070429: ROTSE-III Optical Limits
  35. GRB 070429: Swift detection of a burst
  36. GRB 070427, Swift-BAT Refined Analysis
  37. LT monitoring of GRB070412
  38. GRB 070427: Swift detection of a burst
  39. GRB 070411, further deep LBT photometry
  40. GRB 070411: Late-time Keck imaging
  41. GRB 070411 : Planned XMM-Newton observation
  42. GRB070419B: Suzaku WAM observation of the prompt emission
  43. GRB 070420, SMARTS optical/IR afterglow observations
  44. GRB 070411, deep LBT photometry
  45. GRB 070420: pseudo-z~1.56 from spectral parameters of the prompt
  46. Konus-Wind observation of GRB 070420
  47. GRB 070411: break in the optical light curve
  48. GRB 070420 Swift-BAT Refined Analysis
  49. GRB070419A: Kuiper Optical detection
  50. GRB070419a: Swift UVOT observations
  51. GRB 070419A: MARGE Observations
  52. GRB 070420: optical rebrightening observed at Mt. John
  53. GRB 070420: Swift XRT refined analysis
  54. GRB070420: Swift UVOT continuing observations
  55. GRB 070411: BART early limit
  56. GRB 070420: Faulkes Telescope South Observations
  57. GBR 070419A: Swift/XRT refined analysis
  58. GRB 070420: TAROT La Silla observatory optical observations
  59. GRB 070420: NIR and optical afterglow confirmed
  60. GRB 070420: Swift detection of a burst with optical afterglow
  61. GRB 070419A: MITSuME Okayama Observations
  62. GRB 070419A: Early Super-LOTIS Observations
  63. GRB 070419B, Swift-BAT refined analysis
  64. GRB 070419A Swift-BAT Refined Analysis
  65. GRB070419B: Confirmation of Optical Transient
  66. GRB 070419A: RAPTOR Detection of Early Emission
  67. GRB 070419B: Swift XRT refined analysis
  68. GRB 070419: Keck/LRIS Absorption Redshift
  69. GRB 070419B: optical afterglow confirmation
  70. GRB 070419A, Optical observations
  71. GRB 070411: Deep VLT detection
  72. GRB070419 - SDSS Pre-Burst Observations
  73. GRB 070419A: SARA observations
  74. GRB 070419A: NAYUTA Optical Observation
  75. GRB 070419A: Faulkes Telescope North Optical Observations
  76. GRB 070419B optical afterglow candidate
  77. GRB 070419A: Optical and IR observations with KANATA
  78. GRB 070419B: optical afterglow candidate
  79. GRB 070419A: Lulin Optical observation
  80. GRB070419A, optical observation
  81. Infrared detection of GRB070419A with UKIRT
  82. GRB 070419A: Kiso Optical observation
  83. GRB070330: Correction to UVOT position
  84. GRB 070419: P60 Confirmation of Optical Afterglow
  85. GRB 070419B: Swift detection of a burst
  86. GRB 070419 optical afterglow candidate
  87. GRB 070419A: ROTSE-III Optical Limits
  88. GRB 070419: Swift detection of a burst
  89. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  90. GRB 070418: Optical and IR observations with KANATA
  91. Trigger 276045: Swift detection of a possible burst
  92. GRB 070406: Swift XRT refined analysis
  93. IBAS Alert n.4202: not a real GRB
  94. GRB 070318, SMARTS optical/IR afterglow observations
  95. GRB 070411: TLS data shows plateau, flares
  96. GRB070412: UKIRT-WFCAM JHK upper limits
  97. GRB070412: Swift UVOT observations
  98. IBAS Alert n.4199: Not a GRB
  99. GRB 070411: Swift/UVOT observations
  100. GRB 070412, Swift-BAT refined analysis

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