Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

16238 results found.

  1. GRB 210912A: Mondy optical afterglow confirmation
  2. GRB 210912A: BOOTES-5/JGT optical afterglow candidate
  3. GRB 210619B: Maidanak and Assy optical observations, broken power law parametrization
  4. GRB 210905A: Swift/UVOT Upper Limits
  5. GRB 210905A: ATCA detection
  6. GRB 210905A: ALMA detection
  7. GRB 210610A: Maidanak and AbAO optical observations
  8. GRB 210905A: REM NIR afterglow detection
  9. GRB 210905A: Continued LCO Optical Observations
  10. GRB 210905A: LCO Optical Detection
  11. GRB 210901A: Swift/UVOT Upper Limits
  12. GRB 210820A: TSHAO optical upper limit
  13. GRB 210901A: LCO Optical Upper Limit
  14. GRB 210827A: Swift/UVOT Upper Limits
  15. GRB 210827A: BOOTES-5/JGT optical upper limit
  16. GRB 210820A: CAHA 2.2m Optical Detection
  17. GRB 210824A: Swift/UVOT Upper Limits
  18. GRB 210826A: Swift/UVOT Upper Limits
  19. GRB 210822A: CAHA 2.2m observations
  20. GRB 210824A: MITSuME Akeno optical upper limits
  21. GRB 210822A: TSHAO continued optical observation
  22. GRB 210822A: VLA detection
  23. GRB 210822A: TSHAO optical observation
  24. GRB 210824A: BOOTES-5/JGT optical upper limit
  25. GRB 210824A: Nanshan/NEXT optical upper limit
  26. GRB 210822A: Abbey Ridge Observatory optical afterglow observation
  27. GRB 210822A: NOT photometry and spectroscopy
  28. GRB 210820A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  29. GRB 210822A: Nanshan/NEXT optical observations
  30. GRB 210822A: RATIR Optical Detections
  31. GRB 210822A: KAIT Optical Afterglow Confirmation
  32. GRB 210822A: Swift detection of a burst with an optical afterglow
  33. GRB 210820A: LT optical upper limit
  34. GRB 210820A: LCO Optical Upper Limit
  35. GRB 210820A: RATIR Optical Detections
  36. GRB 210820A: NOT optical upper limit
  37. GRB 210820A: Nanshan/NEXT optical upper limit
  38. GRB 210820A: Swift detection of a burst with an optical counterpart
  39. GRB 210818A: Swift detection of a burst with an optical counterpart
  40. GRB 210807A: continued Assy, AbAO and Mondy observations
  41. GRB 210807A: Tautenburg observations
  42. GRB 210807C: Swift/UVOT Upper Limits
  43. GRB 210807A: correction to the GCN Circ. #30614 Assy optical observations
  44. GRB 210610B: Assy optical observations
  45. GRB 210807A: BOOTES-5/JGT optical afterglow detection
  46. GRB 210807A: Swift detection of a burst with an optical counterpart
  47. GRB 210802A: MITSuME Okayama optical upper limits
  48. GRB 210802A: BOOTES-2/TELMA optical upper limit
  49. GRB 210731A: continued GROND observations
  50. GRB 210731A: KAIT Optical Detection
  51. GRB 210731A: MASTER optical afterglow detection
  52. GRB 210731A: GROND observations
  53. GRB 210731A: Swift/UVOT Detection of an optical afterglow
  54. GRB 210731A: MeerLICHT optical afterglow detection
  55. GRB 210730A: Campo Imperatore optical observations
  56. GRB 210730A: BOOTES-5/JGT and 2.2m CAHA telescopes optical limit
  57. GRB 210730A: TNG optical observations
  58. GRB 210730A: Swift/UVOT Upper Limits
  59. GRB 210724A: Corrected Swift-XRT enhanced position
  60. GRB 210702A: MeerKAT radio detection
  61. GRB 210726A: RATIR Optical Upper Limits and Candidate Host Galaxy
  62. GRB 210725A: AbAO optical upper limit
  63. GRB 210724A: Swift/UVOT Upper Limits
  64. GRB 210723A: Swift/UVOT Upper Limits
  65. GRB 210725A: Swift/UVOT Upper Limits
  66. GRB 210725B: Swift/UVOT Upper Limits
  67. GRB 210726A: CAHA 2.2m telescope optical limit
  68. GRB 210724A: Zeiss-1000 of Koshka observatory, optical upper limit
  69. GRB 210724A: Afterglow candidate from OSIRIS/GTC
  70. GRB 210725A: MITSuME Akeno optical upper limits
  71. GRB 210722A: continued Assy optical observations
  72. GRB 210722A: Nanshan/NEXT further optical observations
  73. GRB 210725A: KAIT Optical Upper Limit
  74. GRB210724A: MeerLICHT upper limits
  75. GRB 210722A: continued Assy optical observations
  76. GRB 210722A: D50 optical detection
  77. GRB 210722A: Kitab optical observations, light curve
  78. GRB 210722A: RATIR Optical Observations
  79. GRB 210722A: GIT optical detection and preliminary analysis
  80. GRB 210722A: Assy optical detection
  81. GRB 210722A: Nanshan/NEXT optical afterglow observations
  82. GRB 210722A: Swift detection of a burst with a bright optical counterpart
  83. Konus-Wind detection of GRB 210714A
  84. Fermi trigger No 647942198: MASTER optical afterglow detection
  85. GRB 210704A: Zeiss-1000/SAO-RAS optical observations
  86. GRB 210712A: Swift/UVOT Upper Limits
  87. GRB 210712A: BOOTES-3/YA optical upper limit
  88. GRB 210704A: Lowell Discovery Telescope Optical Observations
  89. GRB 210704A: Continued Gemini-North NIR K-band Detections
  90. GRB 210704A: NOT optical observations and color change
  91. GRB210704A: Gemini near-infrared upper limits
  92. GRB 210704A: Assy optical afterglow upper limit
  93. GRB 210704A: OSIRIS/GTC Observations and Archival Detection of the Possible Host Galaxy
  94. GRB 210704A: Gemini-North Infrared Source Detection
  95. GRB 210704A: further TNG optical observations
  96. GRB 210708A: Swift/UVOT Upper Limits
  97. GRB 210702A: ATCA detection
  98. GRB 210702A: ALMA detection
  99. GRB 210704A: CAHA 2.2m telescope optical limit
  100. GRB 210706A: optical upper limit of Sintesz-Newton/CrAO and AS-32/AbAO

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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