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"

15716 results found.

  1. GRB 070219: ROTSE-III Optical Limits
  2. GRB 070129: MDM I-band Detection
  3. GRB 070125: Break in Optical Decay
  4. GRB070208: optical observations
  5. GRB 070208: MARGE Optical Observations
  6. GRB 070208: RAPTOR detection of early afterglow onset
  7. GRB070208: Absorption and emission redshift from Gemini
  8. GRB 070208: MDM Optical Decay
  9. GRB 070208: Early IR detection and afterglow astrometry
  10. GRB 070208: ROTSE-III Optical Limits
  11. GRB 070208: MDM Observations
  12. GRB 070125 detection with CARMA
  13. GRB 070125: Redshift z>~1.54 from Gemini Afterglow Spectrum
  14. GRB 070125: further AAVSO optical observations
  15. GRB 070125: optical observation
  16. GRB 070125: WSRT Radio Detection
  17. GRB070129: MITSuME optical observation
  18. GRB061217: MAGIC telescope GeV observation
  19. GRB 070129, Swift-BAT refined analysis of a particularly long
  20. GRB 070129: Xinglong TNT optical Upper Limit
  21. GRB 070125: further AAVSO optical observations
  22. GRB 070125: MITSuME Okayama optical observation
  23. GRB 070125: AAVSO optical observations
  24. GRB 070125: optical observations
  25. GRB 070125: WSRT Radio Observations
  26. GRB070125: Optical observation by Kanata
  27. Possible GRB 070126: Swift/UVOT Upper Limit
  28. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  29. GRB 070125: Xinglong TNT optical observations
  30. GRB 070125: Continued P60 Observations
  31. GRB070125: Swift-XRT Refined Analysis
  32. GRB 070125: P60 Optical Afterglow Candidate
  33. GRB 070110: optical break
  34. GRB 070110: Continued Detection and Request for Ground Followup
  35. GRB 070110 declared a "Burst of Interest" by Swift team
  36. GRB 070110: VLT absorption redshift
  37. GRB 070110: UVOT Observations of a Candidate Afterglow
  38. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  39. GRB 070110: Swift detection of a burst with a possible optical afterglow
  40. GRB070107: Swift/XRT refined analysis
  41. GRB 061201: Nearby Galaxy Cluster Abell 995 is at z=0.0865
  42. GRB 070103: TAROT Calern observatory optical observations
  43. GRB061222a: optical observations
  44. GRB 061210: Swift/XRT Astrometry Correction
  45. GRB 050826: MDM Redshift
  46. GRB 061222B: TAROT La Silla observatory early optical observations
  47. GRB 061218: TAROT La Silla observatory early optical observations
  48. GRB 061222A: MITSuME Akeno optical upper limits
  49. GRB 061222B: MITSuME Akeno optical upper limits
  50. GRB 061222A: Xinglong Optical Limit
  51. GRB061222A Swift/UVOT: Upper Limits
  52. GRB 061222B: Observation with the KANATA 1.5m telescope
  53. GRB061222B: Swift-XRT Refined Analysis
  54. GRB 061222A: Observation with the KANATA 1.5m telescope
  55. GRB 061222B: BOOTES-IR optical observations
  56. GRB 061222B: REM NIR/optical observations
  57. GRB 061222b, SMARTS optical/IR afterglow observations
  58. GRB 061222B: TAROT La Silla observatory optical observations
  59. GRB 061222b: optical afterglow
  60. GRB 061222A: Prompt ROTSE-III Optical Limits
  61. GRB 061217: Astrometry-Corrected XRT Position
  62. GRB 061201: Magellan redshift of nearby galaxy
  63. GRB 061217, Candidate host galaxy
  64. GRB 061218: TAROT La Silla observatory optical observations
  65. GRB 061217: TAROT Calern observatory optical observations
  66. GRB 061218: TORTOREM optical upper limits
  67. GRB 061218, SMARTS optical/IR observations
  68. GRB 061218: REM prompt observations
  69. GRB 061217, SMARTS optical observations
  70. GRB061217: Swift/UVOT refined analysis.
  71. GRB 061217: optical observations at Calar Alto
  72. GRB 061217: REM prompt observations
  73. GRB 061217: ROTSE-III Optical Limits
  74. GRB 061210: MDM Follow-up Observation
  75. GRB061210: Swift/UVOT observations
  76. GRB 061210: Optical sources near XRT positions
  77. GRB 061210 : Faulkes North Telescope optical limit
  78. GRB 061214(?): ROTSE-III Optical Limits
  79. GRB 061213: MASTER-VWF-Kislovodsk optical candidate
  80. GRB061201, VLT optical decay: correction
  81. Optical Afterglow observations of GRB 061126
  82. GRB061126: optical observations
  83. GRB 060926: MASTER: discovery of the optical flare
  84. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  85. GRB 061202: TORTOREM optical upper limits
  86. GRB 061201: VLT optical decay
  87. GRB061126 : NMSU 1.0m observations
  88. GRB061202 optical limit by "Pi of the Sky"
  89. GRB061202: optical/NIR observations with REM
  90. GRB 061201: Swift XRT Team refined analysis
  91. GRB 061201: VLT optical observations
  92. GRB 061201: Initial UVOT Observations
  93. GRB 061122: GETS observation
  94. GRB 061121, SMARTS optical/IR observations
  95. INT+WFC observations of GRB 061126
  96. GRB 061121: Second Epoch ATCA Radio Observations
  97. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  98. GRB 061121: ATCA & WSRT Radio Observations
  99. GRB061121: optical observations
  100. GRB 061126: Early Super-LOTIS Observations

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