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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"

16152 results found.

  1. GRB 220501A: BOOTES-1 optical upper limit
  2. GRB 220501A: GRANDMA/TJML Optical Observations
  3. GRB 220430A: CAHA 2.2m telescope optical limit
  4. GRB 220430A: GRANDMA observations
  5. GRB 220430A: Mondy and AbAO optical upper limits
  6. GRB 220430A: MeerLICHT optical upper limits
  7. GRB 220427A: VLT/X-shooter photometry
  8. GRB 220427A: Swift detection of a burst with an optical counterpart
  9. Fermi-LAT Gamma-ray Observations of IceCube-220425A
  10. GRB 220412B: Swift/UVOT Upper Limits
  11. GRB 220412B: TNG optical observations
  12. GRB 220412A: GRANDMA observations
  13. GRB 220412A: Continued RATIR Observations and Steepening of the Light Curve
  14. GRB 220412A: BOOTES-network optical upper limits
  15. GRB 220412B: BOOTES-1 optical upper limit
  16. GRB 220412A: RATIR Observations of the Fading Afterglow
  17. GRB 220408A: HCT optical upper limit
  18. GRB 220412B: GIT optical upper limit
  19. GRB 220412A: MITSuME Akeno optical upper limits
  20. GRB 220412B: MITSuME Akeno optical upper limits
  21. GRB 220412A: Swift/UVOT Upper Limits
  22. GRB 220408A: GRANDMA observations
  23. GRB 220408A: Lowell Discovery Telescope Optical Observations
  24. GRB 220408A: RATIR Optical and NIR Observations
  25. GRB 220403B: 1.3m DFOT Optical upper limit
  26. GRB 220408A: 1.3m DFOT Optical upper limit
  27. GRB 220408A: LOAO, DOAO, and, SAO optical upper limit
  28. GRB 220408A: NOT optical observations and archival detection
  29. GRB 220408A: LCO Optical Afterglow Detection
  30. GRB 220408A: BOOTES-5/JGT optical afterglow detection
  31. GRB 220408A: GIT optical upper limit
  32. GRB 220408A: Xinglong-2.16m optical upper limit
  33. GRB 220408A: KAIT Optical Observations
  34. GRB 220408A: Swift detection of a burst with an optical counterpart, possibly associated with M51
  35. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, SAO RAS, CrAO)
  36. GRB 220403B: Mondy optical upper limit
  37. GRB 220403B: 1.5m OSN optical observation
  38. GRB 220403B: Kitab optical observations
  39. GRB 220403B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  40. GRB 220403B: Fermi GBM detection
  41. GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
  42. GRB 220403A: Tautenburg observations
  43. GRB 220403B: optical detection by D50
  44. GRB 220403B: Swift detection of a burst with an optical counterpart
  45. ZTF22aaajecp/AT2022cmc: 1.3m DFOT Optical observations
  46. GRB 220325A: Swift/UVOT Upper Limits
  47. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, TSHAO, AbAO)
  48. GRB 220325A: LCO Optical Upper Limits
  49. GRB 220325A: 1.3m DFOT Optical upper limit
  50. GRB 220325A: MASTER Global Robotic Net optical observations
  51. GRB 220319A: MITSuME Akeno optical upper limits
  52. GRB220319A: Optical observations from NOT
  53. GRB 220319A: LCO Optical Upper Limit
  54. GRB 220319A: Mondy optical uper limit
  55. GRB 220319A: MASTER Global Robotic Net optical observations
  56. GRB 220310A: MITSuME Akeno optical observation
  57. IceCube-220317A: MASTER Global Robotic Net optical observations
  58. GRB 220315A: MASTER Global Robotic Net optical observations
  59. GRB 220306B: Swift/UVOT Upper Limits
  60. GRB 220311A: MITSuME Akeno optical upper limits
  61. IPN triangulation of GRB 220310A
  62. GRB 210722A: TAROT Reunion observatory optical light curve
  63. GRB 210222B: TAROT Reunion observatory optical light curve
  64. GRB 201021C: TAROT Reunion observatory optical light curve
  65. GRB 220310A: K-800 of Terskol observatory optical upper limit
  66. GRB 220310A: [KAO-Egypt] SDSS r, i observation
  67. Integral GRB220311.69: Global MASTER-Net OT detection
  68. ZTF22aabjpxh/AT2022cva (GRB 220219B): evidence of supernova in LBT spectra
  69. GRB 220310A: GIT confirmation of optical afterglow.
  70. GRB 220306B: Nanshan/NEXT optical upper limit
  71. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, possible photometric evidence of SN
  72. GRB 220310A: MASTER optical counterpart detection
  73. GRB 220306B: Mondy optical observations, confirmation afterglow candidate
  74. GRB 220306B: AbAO optical observations, possible afterglow candidate
  75. GRB 220306B: BOOTES-1 optical upper limit
  76. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, SN signature search
  77. GRB 220302A: Swift/UVOT Upper Limits
  78. Tev Blazar as possible optical counterpart of the high-energy neutrino IceCube-220303A
  79. GRB 220302A: BOOTES-5/JGT optical upper limit
  80. ZTF22aaajecp/AT2022cmc: AMI-LA radio detection
  81. ZTF22aaajecp/AT2022cmc: Mondy optical observations
  82. Konus-Wind observation of GRB 220219B
  83. GRB 220219B: Swift-XRT observations
  84. ZTF22aabjpxh/AT2022cva (GRB 220219B): Mondy optical observations
  85. ZTF22aaajecp/AT2022cmc: Swift Observation and a UV Detection
  86. ZTF22aabjpxh/AT2022cva: 1.5m OSN optical observation
  87. ZTF22aabjpxh/AT2022cva: Assy optical observations
  88. ZTF22aaajecb/AT2022cmc: Submillimeter Array detection
  89. ZTF22aaajecp/AT2022cmc: Terskol observatory optical observations
  90. IPN triangulation of GRB 220219B (consistent with ZTF22aabjpxh/AT2022cva)
  91. IceCube Alert 220220.60:NuEm-220220A: MASTER optical possible counterpart
  92. ZTF22aabjpxh/AT2022cva: ZTF Discovery of a Rapidly Fading Transient with a Likely Long-GRB Counterpart
  93. GRB 220218A: BOOTES-5/JGT optical upper limit
  94. ZTF22aaajecp/AT2022cmc: Keck DEIMOS Redshift
  95. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory continued optical observations
  96. ZTF22aaajecp/AT2022cmc: VLT/X-shooter redshift
  97. GRB 220211A: MASTER optical observations of ZTF22aaajecp/AT2022cmc
  98. ZTF22aaajecp: GIT optical follow-up observations
  99. ZTF22aaajecp/AT2022cmc: Liverpool Telescope photometry
  100. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory optical observations

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