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"

19806 results found.

  1. GRB 071010B correction to GCN 6892 optical observations
  2. GRB 071011: Swift-XRT refined analysis
  3. VLA non-detection of GRB 071010A
  4. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  5. GRB 071011: Confirmation of P60 optical afterglow
  6. GRB 071010B: Optical Detection
  7. GRB 071011: Kanazawa Optical limits
  8. GRB 071011: P60 Optical Afterglow Candidate
  9. GRB 071011: MARGE Optical Limits
  10. GRB 071010B: Super-LOTIS upper limit
  11. GRB 071010B optical photometry
  12. GRB 071011: XRT afterglow detection
  13. GRB 071011: NAYUTA Optical Observation
  14. GRB 071010A: Continued Keck Imaging
  15. GRB 071010B: Bright OT confirmed with TLS
  16. Optical Observation: GRB 071010
  17. Optical observations: GRB 071010A
  18. GRB071010B: Swift/XRT detection
  19. GRB 071010A: Keck/LRIS Photometry
  20. GRB 071010 REM NIR observations
  21. GRB 071010: TAROT La Silla observatory detection of the afterglow
  22. Radio detection of GRB 071003 with the VLA
  23. GRB 070810B: further XRT analysis
  24. Konus-Wind observation of GRB 071003
  25. GRB 071003: Possible rebrightening
  26. GRB 071003 : Lulin R-band observations
  27. GRB 071003: OA power-law decay indices from KAIT
  28. GRB 071003: P60 Confirmation of Optical Afterglow
  29. Faulkes Telescope South observations of GRB 071001
  30. GRB 071001: Swift detection of a burst
  31. VLA observation of GRB 070923
  32. GRB 070911, SMARTS optical/IR afterglow observations
  33. GRB070925: Swift-XRT Afterglow confirmation
  34. GRB 070925: Gemini South Imaging
  35. GRB 070920B: ROTSE-III Early Optical Limits
  36. GRB 070920B: TAROT La Silla observatory optical observations
  37. INTEGRAL ToO observations of SGR1806-20
  38. GRB 070920B: NOT optical observations
  39. GRB 070920: TAROT Calern observatory optical observations
  40. SGR1806-20: Swift-BAT detection of enhanced activity
  41. GRB 070917: P60 Observations
  42. GRB 070917: MITSuME Akeno Ic upper limit
  43. GRB 070917: R band observations
  44. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  45. GRB 070809: The Swift evidence for the SHB nature of this burst
  46. GRB 070913: Swift-BAT refined analysis
  47. GRB 070913: SMARTS optical/IR observations
  48. GRB 070913: TAROT La Silla observatory optical observations
  49. Swift-BAT Notices back to autonomous real-time distribution
  50. GRB 070911: PAIRITEL IR Observations
  51. GRB 070911: Swift detection of a burst
  52. GRB 070809: Confirmation of optical transient
  53. Candidate Orphan GRB Optical Transient in IC 4779
  54. Las Campanas observations of possible TAROT GRB transient near IC
  55. Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
  56. GRB 070824 - Combined SuperAGILE/IPN Localization
  57. Konus-Wind observation of very bright GRB 070821
  58. GRB 070731: Swift/UVOT Upper Limit
  59. IPN Localization of GRB 070821 (long, very bright)
  60. GRB 070805: UVOT afterglow candidate retraction
  61. GRB 070810A: ROTSE-III Refined Analysis
  62. GRB 070810B : Faulkes Telescope South Observations
  63. GRB 070810A: Continued Keck Imaging
  64. GRB 070810B: Keck spectroscopy of possible host galaxies
  65. GRB070810B: Swift/UVOT Upper Limits
  66. GRB 070810B: XRT refined analysis
  67. GRB 070810B: Xinglong TNT optical Upper Limit
  68. GRB070810B: Optical observations with KANATA
  69. A giant outburst from Cygnus X-1 detected by Konus-Wind and Suzaku-WAM
  70. GRB 070809: Swift/UVOT Upper Limits
  71. VLA upper limit on the short hard burst GRB 070729
  72. No radio detection in superAGILE burst 070724B
  73. GRB 070809: Keck Imaging
  74. GRB 070810: enhanced Swift-XRT position
  75. GRB 070810: Swift/UVOT Optical Counterpart
  76. GRB 070808: Swift/UVOT upper limits
  77. GRB 070809: Swift detection of a short burst
  78. GRB 070808 : Faulkes Telescope South Observations
  79. GCN Swift XRT update position notices and enhanced position circulars
  80. GRB 070808: Swift XRT refined analysis
  81. GRB 070808: Xinglong TNT optical Upper Limit
  82. GRB070808: Optical observations with KANATA
  83. GRB070808 - SDSS Pre-Burst Observations
  84. GRB 070808: ROTSE-III Optical Limits
  85. GRB070805 XRT and UVOT afterglow candidate
  86. GRB070612A: Radio upper limit from GMRT
  87. Swift/UVOT observations of GRB070805
  88. UVOT observations of SAXJ1810.8-2609
  89. Swift detection of a outburst from SAX J1810.8-2609
  90. VLA non-detection of GRB 070721B
  91. GRB 070802: REM optical observations
  92. GRB 070802: Swift-XRT refined analysis
  93. GRB070802: Swift/UVOT upper limits
  94. GRB 070802: V-band detection of the candidate afterglow
  95. GRB 070802: GROND J band candidate
  96. Swift/UVOT detection of GRB070714B
  97. AGILE-ACS position for the SGR 1806-20 July 27 burst
  98. VLA upper limit on short hard burst GRB 070714B
  99. GRB070729: Swift/UVOT upper limits
  100. GRB 070729: Swift-XRT 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